COCOS-432 - FDE support (#553)

* initial FDE setup * add Manager support * fix igvmmeasure build * rebase on main * add tests * NOISSUE - Allow interoperability with CC Attestation Agent (#568) * feat: Add Confidential Containers attestation agent as an alternative attestation backend with new proto definitions and build system integration. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: Update protoc-gen-go and protoc-gen-go-grpc versions in CI workflow Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add mock implementation for AttestationAgentServiceClient and corresponding tests Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: Add missing periods to test function comments in provider_test.go Signed-off-by: Sammy Oina <sammyoina@gmail.com> --------- Signed-off-by: Sammy Oina <sammyoina@gmail.com> * NOISSUE - Agent Pull mode for remote resources (#575) * feat(kbs): implement KBS client for attestation and resource retrieval - Added KBS client implementation in pkg/kbs/client.go with methods for attestation and resource retrieval. - Introduced necessary data structures for requests and responses. - Implemented error handling for various scenarios. test(kbs): add unit tests for KBS client - Created comprehensive tests for the KBS client in pkg/kbs/client_test.go. - Included tests for attestation success and failure cases, as well as resource retrieval. feat(registry): introduce HTTP and S3 registry implementations - Added HTTPRegistry for downloading resources over HTTP/HTTPS with retry logic in pkg/registry/http.go. - Implemented S3Registry for downloading resources from AWS S3 and S3-compatible services in pkg/registry/s3.go. - Included error handling and configuration options for both registries. chore(registry): define registry interface and configuration - Created registry interface and configuration struct in pkg/registry/registry.go. - Added default configuration settings for registry clients. docs(cvms): update README for CVMS server configuration and usage - Enhanced documentation for CVMS server with detailed command-line flags and usage examples. - Clarified direct upload and remote resource modes, including KBS integration. fix(cvms): integrate KBS for remote resource handling in main.go - Updated main.go to support remote datasets and algorithms using KBS. - Added validation for command-line flags to ensure proper configuration. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: Move ifeq conditional outside define block in attestation-service.mk Make conditionals cannot be evaluated inside define...endef blocks when used as recipe bodies. Restructured to define the ATTESTATION_SERVICE_INSTALL_INIT_SYSTEMD block conditionally based on BR2_PACKAGE_CC_ATTESTATION_AGENT configuration. * feat: Implement remote resource downloading for algorithms and datasets using AWS S3/MinIO credentials. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add comprehensive documentation and agent support for testing remote resource download with KBS attestation. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Improve agent logging for remote resource configuration and KBS status, and add a testing guide for remote resource downloads with KBS attestation. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add a comprehensive guide for testing remote resource download with KBS attestation and update multiple package versions to a specific commit. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add failure transitions for resource reception states and a comprehensive guide for testing remote resource downloads with KBS attestation. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Implement remote resource download with KBS attestation in the agent and add a comprehensive testing guide. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * test: Add comprehensive guide for testing remote resource download with KBS attestation and include a debug log in the attestation client. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Delegate KBS attestation and token retrieval to a new attestation-agent service and document remote resource testing. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * client fixes Signed-off-by: Sammy Oina <sammyoina@gmail.com> * raw evidence Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: Build all Go files in cmd directories, not just main.go This fixes the issue where fetch_raw_evidence.go wasn't being included in the attestation-service build. * fix: Wrap binary evidence in JSON for KBS compatibility Fixes 'invalid character' error by wrapping raw binary evidence in a JSON structure with base64 encoding, as expected by KBS. * chore: Update buildroot packages to c28cefae Includes fixes for: 1. attestation-service build (including fetch_raw_evidence.go) 2. Agent KBS evidence format (wrapping binary in JSON) * fix: Implement KBS RCAR handshake with cookies Fixes 'cookie not found' error (401) from KBS by: 1. Adding CookieJar support to KBS client 2. Implementing GetChallenge() to perform /auth handshake and capture session cookie 3. Updating Agent to get challenge, decode nonce, and use it for evidence generation 4. Regenerating mocks * chore: Update buildroot packages to f6981ac5 Includes KBS RCAR handshake fix (cookie support + GetChallenge loop) * fix: Update KBS client JSON tags to kebab-case Fixes deserialization error (401) from KBS by: 1. Using kebab-case (e.g. extra-params) for JSON tags as per protocol. 2. Initializing ExtraParams as empty object {} instead of null/omitted. * fix: Wrap attestation evidence in primary_evidence format Updates Agent to construct 'tee-evidence' payload with: - primary_evidence: containing the actual quote/data - additional_evidence: empty JSON object This matches the Confidential Containers KBS Attestation Protocol requirements. * fix: Update KBS protocol version to 0.4.0 KBS rejected 0.1.0 with a version mismatch error. Bumping to 0.4.0 to match server expectation. * fix: Generate ephemeral key for KBS RuntimeData Updates RuntimeData to include a valid ephemeral EC P-256 public key in JWK format, as required by the KBS RCAR protocol. Also fixes the KBS client struct to support TEEPubKey as an object. * fix: Update sample attestation quote to valid JSON The default attestation.bin was binary, but the KBS Sample Verifier expects a valid JSON quote containing 'svn' and 'report_data'. Updated the embedded bin file to contain this JSON structure. * fix: Generate dynamic JSON quote for Sample TEE in FetchRawEvidence The KBS Sample Verifier expects a JSON object with 'svn' and 'report_data'. Previously, we were returning raw binary data (reportData+nonce). This commit updates FetchRawEvidence to return a marshaled JSON structure with: - svn: "1" - report_data: base64(req.ReportData) * refactor: Delegate Sample Attestation to Provider Refactored sample attestation logic: - Moved JSON Quote generation into EmptyProvider (standalone mode). - Updated FetchRawEvidence to call provider.TeeAttestation instead of manual generation. This enables using the real CC Attestation Agent for UNSPECIFIED platform if configured. * feat: Add comprehensive debug logging and enforce CC AA usage Changes: - Updated EmptyProvider to return error instead of generating mock data This forces proper use of CC Attestation Agent's sample attester - Added detailed logging to attestation-service FetchRawEvidence: * Hex dump of evidence (first 200 bytes) * String preview of evidence * Total evidence length - Added detailed logging to agent service: * Raw evidence hex and string previews * KBS evidence JSON preview (first 500 bytes) * Evidence lengths at each transformation step This logging will help diagnose why KBS Sample Verifier is rejecting evidence. * fix: Enable CC AA by default and add attestation-service log forwarding Changes: - Set USE_CC_ATTESTATION_AGENT=true by default in systemd service - Added StandardOutput/StandardError to forward logs to /var/log/cocos/ - Updated HAL makefile to handle new default value - This ensures attestation-service uses CC AA's sample attester - Logs will now be visible in CVMS output for debugging * feat: Add gRPC log forwarding to attestation-service Implemented the same log forwarding mechanism used by the agent: - Added ProtoHandler to write logs to both stdout and logQueue - Connected to log client (/run/cocos/log.sock) for gRPC forwarding - Added goroutine to forward logs to CVMS via log client - Logs will now appear in CVMS output during computation runs This enables visibility into attestation-service debug output including: - CC AA connection status - Evidence generation details (hex dumps, string previews) - Any errors from providers * fix: Parse sample evidence JSON instead of base64-encoding it The attestation-service returns sample evidence as JSON: {"svn":"1","report_data":"base64..."} The agent was incorrectly base64-encoding this JSON string again. KBS Sample Verifier expects the parsed JSON object directly. Fixed by: - Parsing the JSON evidence from attestation-service - Passing the parsed object directly in primary_evidence.evidence - This matches what KBS Sample Verifier expects * debug: Increase KBS evidence logging preview to 1000 bytes Show the complete JSON structure being sent to KBS to debug the attestation failure. * debug: Add comprehensive CC AA configuration logging Added debug logs to show: - Whether CC AA is enabled in config - CC AA address being used - Connection success/failure - Which provider is ultimately selected - Warning when falling back to EmptyProvider This will help diagnose why EmptyProvider is being used instead of CC Attestation Agent. * debug: Add startup logging for log client connection Added log message to show if log client connection succeeds at attestation-service startup. This will help diagnose why logs aren't appearing in CVMS output. * feat: Add retry logic with exponential backoff to log client Added simple retry mechanism to handle concurrent log requests: - 3 retry attempts with exponential backoff (10ms, 20ms, 40ms) - Applies to both SendLog and SendEvent methods - Centralized in log client so all services benefit - Should eliminate 'failed to send log' errors from concurrent requests This fixes the issue where attestation-service logs weren't appearing in CVMS output due to dropped messages. * fix: Flatten sample evidence fields in primary_evidence for KBS KBS Sample Verifier expects svn and report_data at the top level of primary_evidence, not nested under an 'evidence' key. Changed structure from: {"primary_evidence": {"tee": "sample", "evidence": {"svn": "1", ...}}} To: {"primary_evidence": {"tee": "sample", "svn": "1", "report_data": "...", ...}} This matches what KBS expects when deserializing the Quote structure. * fix: Use sample quote directly as primary_evidence per KBS protocol According to KBS attestation protocol spec, for sample TEE type, primary_evidence should be the sample quote JSON directly: {"svn": "1", "report_data": "..."} Removed extra 'tee' and 'platform' fields that were causing KBS to fail deserializing the Quote structure. The 'tee' field is already sent in the Request payload during RCAR handshake. Refs: - https://github.com/confidential-containers/trustee/blob/main/kbs/docs/kbs_attestation_protocol.md - https://github.com/confidential-containers/guest-components/blob/main/attestation-agent/attester/src/sample/mod.rs * fix: Make CC AA required for sample attestation when configured When USE_CC_ATTESTATION_AGENT=true, attestation-service now requires AA to be available for NoCC/sample platform. This ensures sample evidence always comes from AA with the correct KBS format. Changes: - Error out if AA connection fails for NoCC platform when AA is configured - Only use EmptyProvider if AA is explicitly NOT configured - Prevents incorrect sample evidence format from EmptyProvider This ensures attestation-service delegates to AA for sample evidence generation instead of creating it itself. * fix: Implement proper RCAR protocol with tee-pubkey and runtime-data hash Fixed KBS attestation error 'REPORT_DATA is different from that in Sample Quote' Changes: 1. Generate ephemeral EC key pair BEFORE getting evidence from AA 2. Create runtime-data with nonce + tee-pubkey (JWK format) 3. Hash runtime-data (SHA-256) and use as report_data for AA 4. This binds the tee-pubkey to the TEE evidence per RCAR protocol The report_data in the evidence now matches what KBS expects: hash(runtime-data) instead of computation ID. This completes the full RCAR protocol implementation: - Request → Challenge → Attestation (with bound tee-pubkey) → Response * fix(agent): use simple nonce for Sample attestation report_data For Sample/NoCC attestation, use the raw nonce bytes directly as report_data instead of hashing runtime-data. This avoids JSON serialization mismatches with the KBS Sample verifier. Real TEEs (TDX/SNP) still use runtime-data hash binding to cryptographically bind the ephemeral tee-pubkey to the evidence. * fix(agent): use RFC 8785 canonical JSON for runtime-data hashing The KBS Sample attestation verifier (and likely others) expects the report_data to be the SHA-256 hash of the *canonical* JSON serialization (RFC 8785) of the runtime-data. Standard Go JSON marshaling does not guarantee key ordering, leading to hash mismatches. This change uses github.com/gowebpki/jcs to canonicalize the runtime-data before hashing, ensuring compatibility with the KBS RCAR implementation. Also reverted the temporary 'simple nonce' workaround. * feat(hal): add CoCo Keyprovider and Skopeo packages - Add coco-keyprovider buildroot package with systemd service - Add skopeo buildroot package for OCI image handling - Add ocicrypt_keyprovider.conf for encrypted image decryption - Update Config.in to include new packages This enables standard CoCo ecosystem integration for encrypted OCI images instead of custom S3/HTTP registry clients. * feat(oci): add OCI image handling package with Skopeo integration - Add pkg/oci/types.go with ResourceSource and ImageManifest types - Add pkg/oci/skopeo.go with Skopeo wrapper for pull/decrypt - Add pkg/oci/extract.go for extracting algorithms and datasets from layers This package provides OCI image handling using Skopeo and CoCo Keyprovider for encrypted image decryption, replacing custom S3/HTTP registry clients. * chore: regenerate protobuf files for updated cvms.proto * refactor(agent): replace S3/HTTP/KBS with OCI package - Remove pkg/kbs and pkg/registry imports - Add pkg/oci import for OCI image handling - Replace downloadAndDecryptResource with OCI-based implementation - Use Skopeo + CoCo Keyprovider for automatic decryption - Reduce code from ~240 lines to ~70 lines This eliminates custom KBS RCAR handshake, S3/HTTP registry clients, and manual decryption logic. CoCo Keyprovider handles all decryption automatically via ocicrypt protocol. * chore: remove obsolete pkg/kbs and pkg/registry packages - Delete pkg/kbs/ (custom KBS client, ~300 lines) - Delete pkg/registry/ (S3/HTTP registry clients, ~400 lines) - Remove unused imports from agent/service.go - Run go mod tidy to clean up dependencies These packages have been replaced by pkg/oci with Skopeo and CoCo Keyprovider for standard CoCo ecosystem integration. * fix(agent): update ResourceSource struct to include type and encryption fields Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix(hal): update CoCo Keyprovider to v0.16.0 and fix build path - Update version from v0.11.0 to v0.16.0 (matches attestation agent) - Fix install path: target is at repo root, not in coco_keyprovider subdir - This fixes the build error where coco_keyprovider binary wasn't found The cargo workspace in guest-components builds to a shared target/ directory at the repository root, not within each crate's subdirectory. * feat: Update remote resources testing guide to use kbs-client and coco-keyprovider for key management and encryption, enable insecure TLS for Skopeo, and enhance CVMS with Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Update component versions, revise image encryption documentation, and sanitize OCI image paths for Skopeo compatibility. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add `decompress` option to Dataset and `algo_type`/`algo_args` to Algorithm protobuf messages, updating client, test, and build configurations. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * Update multiple package versions and enhance OCI image extraction error reporting for missing algorithm files. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * chore: Bump package versions, improve OCI image extraction debugging by returning seen files, and remove unused dataset type parsing from test code. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * refactor: Migrate OCI extraction to use structured logging with `slog` and `context`, and update package versions. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Bump multiple component versions, add encrypted status for computation inputs and algorithms, and refine OCI layer extraction warnings. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * logging Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: Add `Encrypted` field to algorithm and dataset resource sources and update all component versions. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: update component versions, integrate coco-keyprovider service, and configure ocicrypt key provider. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: add support for KBS parameters and dataset/algorithm hash calculations in CVMS Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: update resource download and extraction logic to support requirements.txt and improve hash verification Signed-off-by: Sammy Oina <sammyoina@gmail.com> * chore: Update dependencies, improve code style, and add GetRawEvidence to attestation client mocks. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * Refactor code structure for improved readability and maintainability Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: update golangci configuration to include errcheck for build path and remove unnecessary exclusions Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: streamline kernel command line handling in QEMU args construction Signed-off-by: Sammy Oina <sammyoina@gmail.com> * feat: add attestation binary and update checksum tests and policy structure Signed-off-by: Sammy Oina <sammyoina@gmail.com> * Add unit tests for attestation agent, attestation, log, crypto, OCI, and Skopeo clients - Implement tests for the attestation agent client including Unix socket and TCP address handling, token retrieval, and error scenarios. - Enhance attestation client tests to cover fetching raw evidence for various platforms (SNP, TDX, VTPM, SNPvTPM) and validate error handling. - Introduce log client tests to verify retry behavior for sending logs and events. - Create comprehensive tests for crypto package focusing on AES-GCM decryption, encrypted resource parsing, and key unwrapping. - Add tests for OCI package to validate algorithm and dataset extraction, including JSON serialization of OCILayout. - Implement Skopeo client tests to ensure proper functionality for image pulling, inspecting, and resource source handling. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: handle JSON marshal errors in test cases for decrypt and extract functions Signed-off-by: Sammy Oina <sammyoina@gmail.com> * test: add comprehensive tests for algorithm and dataset extraction with various scenarios Signed-off-by: Sammy Oina <sammyoina@gmail.com> * refactor: replace hardcoded Python script content with constant variable Signed-off-by: Sammy Oina <sammyoina@gmail.com> * fix: remove redundant mock expectation for SendAgentConfig in TestCreateVMWithAaKbsParams Signed-off-by: Sammy Oina <sammyoina@gmail.com> * test: add tests for event sending failure, dataset extraction with path traversal, and Skopeo client behavior Signed-off-by: Sammy Oina <sammyoina@gmail.com> * test: add tests for download and decryption of resources with various URL formats Signed-off-by: Sammy Oina <sammyoina@gmail.com> * refactor: Introduce OCIClient interface for agent service to improve testability of OCI image operations and enhance related tests. Signed-off-by: Sammy Oina <sammyoina@gmail.com> * refactor: Change `get_uint64_from_tcb` to accept `TcbVersion` by value and use `u64::from` for type conversions. --------- Signed-off-by: Sammy Oina <sammyoina@gmail.com> * initial FDE setup * add Manager support * add cloud-init script * rebase onto main * add blank lines * add tdx rtmr support * add FDE flow * use DiskConfig.Format instead of fixed values * add tests and expand Manager README.md * add curl command * add encrypted partition support * remove nbd * add dm-verity * fix manager boot sequence --------- Signed-off-by: Sammy Oina <sammyoina@gmail.com> Co-authored-by: ultraviolet <cocosai@worker-52.local.pragmatic-it.com> Co-authored-by: Sammy Kerata Oina <44265300+SammyOina@users.noreply.github.com>
2026-06-22 20:00:18 +00:00 · 2026-05-08 14:59:13 +02:00
parent d5badba547
commit 81fe0b11b5
54 changed files with 2436 additions and 30 deletions
@@ -85,6 +85,29 @@ var (
 	ImaPcrIndex             = 10
 )

+func ensureDir(path string, mode os.FileMode) error {
+	info, err := os.Stat(path)
+	switch {
+	case err == nil:
+		if info.IsDir() {
+			return nil
+		}
+		if err := os.Remove(path); err != nil {
+			return fmt.Errorf("removing non-directory path %q: %w", path, err)
+		}
+	case os.IsNotExist(err):
+		// Continue and create it below.
+	default:
+		return fmt.Errorf("stating path %q: %w", path, err)
+	}
+
+	if err := os.MkdirAll(path, mode); err != nil {
+		return fmt.Errorf("creating directory %q: %w", path, err)
+	}
+
+	return nil
+}
+
 var (
 	// ErrMalformedEntity indicates malformed entity specification (e.g.
 	// invalid username or password).
@@ -478,8 +501,8 @@ func (as *agentService) downloadAlgorithmIfRemote(state statemachine.State) {
 		as.algoReceived = true
 		as.algoRequirements = res.Requirements // Store requirements for installation

-		// Create datasets directory
-		if err := os.Mkdir(algorithm.DatasetsDir, 0o755); err != nil {
+		// The initramfs may have already provisioned /cocos/datasets.
+		if err := ensureDir(algorithm.DatasetsDir, 0o755); err != nil {
 			as.runError = fmt.Errorf("error creating datasets directory: %w", err)
 			as.logger.Error(as.runError.Error())
 			as.sm.SendEvent(RunFailed)
@@ -976,7 +999,7 @@ func (as *agentService) Algo(ctx context.Context, algo Algorithm) error {
 	as.algoRequirements = algo.Requirements
 	as.algoReceived = true

-	if err := os.Mkdir(algorithm.DatasetsDir, 0o755); err != nil {
+	if err := ensureDir(algorithm.DatasetsDir, 0o755); err != nil {
 		return fmt.Errorf("error creating datasets directory: %v", err)
 	}

@@ -1145,7 +1168,7 @@ func (as *agentService) runComputation(state statemachine.State) {
 		}
 	}()

-	if err := os.Mkdir(algorithm.ResultsDir, 0o755); err != nil {
+	if err := ensureDir(algorithm.ResultsDir, 0o755); err != nil {
 		as.mu.Lock()
 		as.runError = fmt.Errorf("error creating results directory: %s", err.Error())
 		as.mu.Unlock()
@@ -0,0 +1,9 @@
+source "$BR2_EXTERNAL_COCOS_PATH/package/agent/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/attestation-service/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/cc-attestation-agent/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/coco-keyprovider/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/wasmedge/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/log-forwarder/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/computation-runner/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/egress-proxy/Config.in"
+source "$BR2_EXTERNAL_COCOS_PATH/package/ingress-proxy/Config.in"
@@ -0,0 +1,214 @@
+# Disk Image Workflow
+
+This directory is the Buildroot external tree for the current Cocos disk test
+VM image and its runtime configuration.
+
+## Layout
+
+- [configs/cocos_defconfig](./configs/cocos_defconfig):
+  Buildroot configuration for the bootable image.
+- [board/rootfs-overlay/init](./board/rootfs-overlay/init):
+  early initramfs script that provisions `/cocos`, mounts the real root, and
+  switches into the installed system.
+- [board/cocos/genimage.cfg](./board/cocos/genimage.cfg):
+  GPT disk layout for the final `disk.img`.
+- [board/cocos/post-image.sh](./board/cocos/post-image.sh):
+  builds the minimal initramfs, stages EFI files, signs boot artifacts, and
+  assembles `disk.img`.
+- [external.desc](./external.desc): Buildroot external tree descriptor.
+- [external.mk](./external.mk): includes package makefiles from `package/*`.
+
+## Current Buildroot Image
+
+The current Buildroot flow produces a bootable GPT disk image:
+
+- `efi` partition: FAT EFI system partition with GRUB, kernel, and initramfs
+- `root` partition: ext4 root filesystem protected by dm-verity
+- `verity` partition: dm-verity hash tree for the root filesystem
+- `cocos` partition: blank partition provisioned at boot as an encrypted ext4
+  filesystem mounted at `/cocos`
+
+The final image is written to:
+
+```bash
+output/images/disk.img
+```
+
+The root filesystem image is also available separately as:
+
+```bash
+output/images/rootfs.ext4
+```
+
+## Current Boot Flow
+
+At boot, GRUB loads:
+
+- `bzImage`
+- `initrd.cpio.gz`
+
+The initramfs script in
+[board/rootfs-overlay/init](./board/rootfs-overlay/init)
+then:
+
+1. mounts `/proc`, `/sys`, `devtmpfs`, and `devpts`
+2. assumes the boot disk is `/dev/sda`
+3. opens a dm-verity mapping for the root filesystem using:
+   - `/dev/sda2` as the data partition
+   - `/dev/sda3` as the verity hash partition
+   - `roothash=` from the kernel command line
+4. mounts `/dev/mapper/root_verity` read-only at `/root`
+5. generates a fresh ephemeral key
+6. formats `/dev/sda4` as LUKS2
+7. opens it as `/dev/mapper/cocos_crypt`
+8. formats that mapper as ext4 and mounts it at `/root/cocos`
+9. creates working directories on `/cocos`, including:
+   - `/cocos/.cache/oci`
+   - `/cocos/datasets`
+   - `/cocos/docker`
+   - `/cocos/cocos_init`
+10. mounts `tmpfs` on `/tmp` and `/var` because the root filesystem is
+   intentionally read-only
+11. bind-mounts `/cocos/docker` onto `/var/lib/docker`
+12. bind-mounts `/cocos/cocos_init` onto `/cocos_init`
+13. rewrites `/etc/fstab` in the mounted root to describe the live runtime
+14. preserves or adds 9P mounts for:
+    - `certs_share` -> `/etc/certs`
+    - `env_share` -> `/etc/cocos`
+15. securely wipes the temporary LUKS key file
+16. runs `switch_root /root /sbin/init`
+
+Important details:
+
+- the root filesystem is verified through dm-verity before it is mounted
+- `/cocos` is encrypted with an ephemeral per-boot key
+- that key is not persisted, so `/cocos` is provisioned fresh on each boot
+
+## Runtime Filesystem Model
+
+The running system is split into:
+
+- read-only root on `/`
+- encrypted writable storage on `/cocos`
+- `tmpfs` on `/tmp`
+- `tmpfs` on `/var`
+
+Service state that must survive within a boot session is redirected away from
+the read-only root:
+
+- Docker data lives on `/cocos/docker`
+- agent setup scripts work through `/cocos_init`, which is backed by
+  `/cocos/cocos_init`
+- algorithm datasets and results live under `/cocos`
+
+This means services can use `/cocos` like a regular directory tree after boot,
+even though it is backed by an encrypted mapper created in early userspace.
+
+## systemd Runtime Expectations
+
+Several services depend on files mounted from 9P shares under `/etc/certs` and
+`/etc/cocos`. To avoid boot-order races, the rootfs overlay includes systemd
+drop-ins under:
+
+```bash
+board/rootfs-overlay/usr/lib/systemd/system/*service.d/
+```
+
+These drop-ins require the relevant mount points before starting services such
+as:
+
+- `egress-proxy.service`
+- `log-forwarder.service`
+- `computation-runner.service`
+- `cocos-agent.service`
+
+The overlay also ships tmpfiles rules in
+[board/rootfs-overlay/usr/lib/tmpfiles.d/cocos.conf](./board/rootfs-overlay/usr/lib/tmpfiles.d/cocos.conf)
+to create:
+
+- `/var/log/cocos`
+- `/run/cocos`
+
+## Agent Packaging In Buildroot
+
+The Buildroot `agent` package is wired to build the binary from the local Cocos
+checkout, not only from a downloaded release snapshot. The package definition is
+in [package/agent/agent.mk](./package/agent/agent.mk).
+
+That package currently:
+
+- builds `cocos-agent` from the local source tree
+- installs the local
+  [cocos-agent.service](../../init/systemd/cocos-agent.service)
+- installs the local
+  [agent_setup.sh](../../init/systemd/agent_setup.sh)
+- installs the local
+  [agent_start_script.sh](../../init/systemd/agent_start_script.sh)
+
+So changes under:
+
+- `cocos/agent/...`
+- `cocos/init/systemd/...`
+
+are intended to be picked up by the next Buildroot rebuild.
+
+## Buildroot Packages And Tools
+
+The current `cocos_defconfig` includes the components needed by the boot flow
+and runtime image, including:
+
+- systemd
+- DHCP client
+- `cryptsetup`
+- `eudev`
+- `e2fsprogs`
+- Docker, containerd, and runc
+- `skopeo`
+- TPM2 tools
+- 9P filesystem support
+- GRUB2 EFI boot support
+- host `genimage`
+
+The initramfs built in `post-image.sh` is intentionally minimal and contains
+only the binaries needed for early boot, dm-verity root verification, and
+`/cocos` provisioning.
+
+## Secure Boot Notes
+
+During `post-image.sh`:
+
+- GRUB is rebuilt with `--disable-shim-lock`
+- `bootx64.efi` and `bzImage` are signed with the configured Secure Boot keys
+  when those keys are present
+
+This flow is designed for booting directly through OVMF with your own enrolled
+keys. It does not currently rely on booting through `shim`.
+
+## Rebuilding
+
+This directory is meant to be used as a Buildroot external tree. From this
+directory, configure a Buildroot checkout with:
+
+```bash
+make -C /path/to/buildroot BR2_EXTERNAL=$PWD cocos_defconfig
+```
+
+Then build with:
+
+```bash
+make -C /path/to/buildroot BR2_EXTERNAL=$PWD -j$(nproc)
+```
+
+The resulting boot image is:
+
+```bash
+/path/to/buildroot/output/images/disk.img
+```
+
+Additional generated artifacts include:
+
+```bash
+/path/to/buildroot/output/images/rootfs.ext4
+/path/to/buildroot/output/images/rootfs.verity
+/path/to/buildroot/output/images/rootfs.roothash
+```
@@ -0,0 +1,42 @@
+image efi-part.vfat {
+    vfat {
+        file EFI {
+            image = "efi-part/EFI"
+        }
+        file bzImage {
+            image = "efi-part/bzImage"
+        }
+        file initrd.cpio.gz {
+            image = "efi-part/initrd.cpio.gz"
+        }
+    }
+    size = 256M
+}
+
+image disk.img {
+    hdimage {
+        partition-table-type = "gpt"
+    }
+
+    partition efi {
+        image = "efi-part.vfat"
+        partition-type-uuid = "C12A7328-F81F-11D2-BA4B-00A0C93EC93B"
+        offset = 1M
+        bootable = true
+    }
+
+    partition root {
+        image = "rootfs.ext4"
+        partition-type-uuid = "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
+    }
+
+    partition verity {
+        image = "rootfs.verity"
+        partition-type-uuid = "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
+    }
+
+    partition cocos {
+        size = "20480M"
+        partition-type-uuid = "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
+    }
+}
@@ -0,0 +1,279 @@
+###
+# Architecture / base
+###
+CONFIG_SYSVIPC=y
+CONFIG_SMP=y
+CONFIG_EXPERT=y
+CONFIG_LOCALVERSION_AUTO=n
+
+###
+# Modules
+###
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+
+###
+# Virtualization
+###
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+CONFIG_VIRTUALIZATION=y
+CONFIG_KVM=y
+CONFIG_KVM_SW_PROTECTED_VM=y
+CONFIG_KVM_INTEL=y
+CONFIG_VIRT_DRIVERS=y
+
+###
+# Cgroups — base + Docker/container subsystems
+###
+CONFIG_CGROUPS=y
+CONFIG_CGROUP_CPUACCT=y
+CONFIG_CGROUP_DEVICE=y
+CONFIG_CGROUP_FREEZER=y
+CONFIG_CGROUP_MISC=y
+CONFIG_CGROUP_PIDS=y
+CONFIG_CGROUP_BPF=y
+CONFIG_CGROUP_NET_PRIO=y
+CONFIG_CGROUP_NET_CLASSID=y
+CONFIG_CPUSETS=y
+CONFIG_MEMCG=y
+CONFIG_BLK_CGROUP=y
+
+###
+# Namespaces — required by containerd / runc
+###
+CONFIG_NAMESPACES=y
+CONFIG_UTS_NS=y
+CONFIG_IPC_NS=y
+CONFIG_USER_NS=y
+CONFIG_PID_NS=y
+CONFIG_NET_NS=y
+
+###
+# PCI
+###
+CONFIG_PCI=y
+CONFIG_PCI_MSI=y
+CONFIG_IRQ_REMAP=y
+
+###
+# Initramfs
+###
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_RD_GZIP=y
+
+###
+# Block devices
+###
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_BLK_DEV_SD=y
+CONFIG_SCSI_VIRTIO=y
+CONFIG_ATA=y
+CONFIG_ATA_PIIX=y
+CONFIG_VIRTIO_BLK=y
+
+# Loop device (used by containerd image mounts)
+CONFIG_BLK_DEV_LOOP=y
+CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
+
+###
+# Device mapper — FDE, dm-verity, dm-crypt, dm-integrity
+# These must be built-in (y) because they are needed before the
+# rootfs is mounted, during the initramfs FDE init stage.
+###
+CONFIG_MD=y
+CONFIG_BLK_DEV_DM_BUILTIN=y
+CONFIG_BLK_DEV_DM=y
+CONFIG_DM_CRYPT=y
+CONFIG_DM_VERITY=y
+CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG=y
+# CONFIG_DM_VERITY_FEC is not set
+CONFIG_DM_INTEGRITY=y
+CONFIG_DM_INIT=y
+
+###
+# Networking — base
+###
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_WIRELESS is not set
+CONFIG_NETDEVICES=y
+CONFIG_VIRTIO_NET=y
+CONFIG_NE2K_PCI=y
+CONFIG_8139CP=y
+# CONFIG_WLAN is not set
+CONFIG_VSOCKETS=y
+CONFIG_VIRTIO_VSOCKETS=y
+
+# Virtual Ethernet pairs and bridge (Docker networking)
+CONFIG_VETH=m
+CONFIG_BRIDGE=m
+CONFIG_BRIDGE_NETFILTER=m
+
+###
+# Netfilter — Docker NAT, iptables, conntrack (modules, loaded on demand)
+###
+CONFIG_NETFILTER=y
+CONFIG_NETFILTER_ADVANCED=y
+CONFIG_NF_CONNTRACK=m
+CONFIG_NF_CONNTRACK_MARK=y
+CONFIG_NF_NAT=m
+CONFIG_NF_NAT_MASQUERADE=y
+CONFIG_NF_TABLES=y
+CONFIG_IP_NF_IPTABLES=m
+CONFIG_IP_NF_FILTER=m
+CONFIG_IP_NF_TARGET_MASQUERADE=m
+CONFIG_NETFILTER_XT_MATCH_ADDRTYPE=m
+CONFIG_NETFILTER_XT_MATCH_CONNTRACK=m
+
+###
+# BPF
+###
+CONFIG_BPF_SYSCALL=y
+
+###
+# Filesystems
+###
+CONFIG_EXT4_FS=y
+CONFIG_OVERLAY_FS=y
+CONFIG_AUTOFS4_FS=y
+CONFIG_TMPFS=y
+CONFIG_TMPFS_POSIX_ACL=y
+CONFIG_PROC_FS=y
+CONFIG_SYSFS=y
+
+###
+# 9P filesystem (virtio shares for certs and env)
+###
+CONFIG_NET_9P=y
+CONFIG_NET_9P_VIRTIO=y
+CONFIG_9P_FS=y
+CONFIG_9P_FS_POSIX_ACL=y
+CONFIG_9P_FS_SECURITY=y
+
+###
+# Virtio devices
+###
+CONFIG_VIRTIO_PCI=y
+CONFIG_VIRTIO_BALLOON=y
+CONFIG_VIRTIO_INPUT=y
+CONFIG_VIRTIO_CONSOLE=y
+CONFIG_VIRTIO_MMIO=y
+CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y
+CONFIG_HW_RANDOM_VIRTIO=m
+
+###
+# Console / Input
+###
+CONFIG_INPUT_EVDEV=y
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+
+###
+# Kernel features required by systemd
+###
+CONFIG_FHANDLE=y
+CONFIG_INOTIFY_USER=y
+CONFIG_SIGNALFD=y
+CONFIG_TIMERFD=y
+CONFIG_EPOLL=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_POSIX_MQUEUE_SYSCTL=y
+CONFIG_UNWINDER_FRAME_POINTER=y
+
+###
+# Security
+###
+CONFIG_SECCOMP=y
+CONFIG_SECCOMP_FILTER=y
+CONFIG_SECURITY=y
+CONFIG_SECURITYFS=y
+
+###
+# EFI
+###
+CONFIG_EFI=y
+CONFIG_EFI_STUB=y
+
+###
+# AMD SEV-SNP
+###
+CONFIG_AMD_MEM_ENCRYPT=y
+CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n
+CONFIG_SEV_GUEST=y
+CONFIG_IOMMU_DEFAULT_PASSTHROUGH=n
+
+###
+# Intel TDX
+###
+CONFIG_X86_X2APIC=y
+CONFIG_X86_CPUID=y
+CONFIG_X86_SGX=y
+CONFIG_X86_SGX_KVM=y
+CONFIG_INTEL_TDX_GUEST=y
+CONFIG_TDX_GUEST_DRIVER=y
+
+###
+# Preemption (disabled for VM performance)
+###
+CONFIG_PREEMPT_COUNT=n
+CONFIG_PREEMPT=n
+CONFIG_PREEMPT_DYNAMIC=n
+CONFIG_DEBUG_PREEMPT=n
+
+###
+# Key/signature management
+###
+CONFIG_SYSTEM_TRUSTED_KEYS=n
+CONFIG_SYSTEM_REVOCATION_KEYS=n
+CONFIG_MODULE_SIG_KEY=n
+CONFIG_KEYS=y
+CONFIG_ENCRYPTED_KEYS=y
+
+###
+# Crypto — AES-GCM (LUKS2 cipher) + SHA-256 (dm-verity hash)
+###
+CONFIG_CRYPTO_AES=y
+CONFIG_CRYPTO_SHA256=y
+CONFIG_CRYPTO_GCM=y
+CONFIG_CRYPTO_GHASH=y
+CONFIG_CRYPTO_SEQIV=y
+CONFIG_CRYPTO_ECHAINIV=y
+CONFIG_CRYPTO_XTS=y
+CONFIG_CRYPTO_CBC=y
+CONFIG_CRYPTO_AUTHENC=y
+CONFIG_CRYPTO_ESSIV=y
+CONFIG_CRYPTO_USER_API=y
+CONFIG_CRYPTO_USER_API_HASH=y
+CONFIG_CRYPTO_USER_API_SKCIPHER=y
+CONFIG_CRYPTO_USER_API_AEAD=y
+CONFIG_CRYPTO_AES_NI_INTEL=m
+CONFIG_CRYPTO_GHASH_CLMUL_NI_INTEL=m
+
+###
+# TPM
+###
+CONFIG_TCG_TPM=y
+CONFIG_TCG_TPM2_HMAC=y
+CONFIG_TCG_PLATFORM=y
+
+###
+# IMA (Linux Integrity Measurement Architecture)
+###
+CONFIG_INTEGRITY=y
+CONFIG_INTEGRITY_SIGNATURE=y
+CONFIG_IMA=y
+CONFIG_IMA_MEASURE_PCR_IDX=10
+CONFIG_IMA_LSM_RULES=y
+CONFIG_IMA_APPRAISE=y
+CONFIG_IMA_DEFAULT_TEMPLATE="ima-ng"
+CONFIG_IMA_DEFAULT_HASH="sha256"
+
+###
+# Disabled options
+###
+CONFIG_KSM=n
+CONFIG_EISA=n
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -u
+set -e
+
+# Add a console on tty1
+if [ -e ${TARGET_DIR}/etc/inittab ]; then
+    grep -qE '^tty1::' ${TARGET_DIR}/etc/inittab || \
+    sed -i '/GENERIC_SERIAL/a\
+tty1::respawn:/sbin/getty -L  tty1 0 vt100 # QEMU graphical window' ${TARGET_DIR}/etc/inittab
+fi
@@ -0,0 +1,273 @@
+#!/bin/bash
+
+COCOS_BOARD_DIR="$(dirname "$0")"
+DEFCONFIG_NAME="$(basename "$2")"
+README_FILES="${COCOS_BOARD_DIR}/readme.txt"
+START_QEMU_SCRIPT="${BINARIES_DIR}/start-qemu.sh"
+
+# ---------------------------------------------------------------------------
+# Build a minimal FDE initramfs (rootfs.cpio.gz) containing only the tools
+# needed to mount the root partition read-only, provision LUKS2, and switch_root.
+# All other packages live
+# on the ext4 disk image and are available after switch_root.
+# ---------------------------------------------------------------------------
+echo "[post-image] Building minimal FDE initramfs..."
+
+INITRAMFS_STAGE="${BUILD_DIR}/initramfs-staging"
+rm -rf "${INITRAMFS_STAGE}"
+
+# Merged-usr layout: bin/sbin/lib/lib64 are symlinks into usr/, matching the
+# Buildroot target layout so that hardcoded ELF interpreter paths (ld-linux)
+# and the #!/bin/sh shebang both resolve correctly inside the initramfs.
+mkdir -p "${INITRAMFS_STAGE}/usr/bin" \
+         "${INITRAMFS_STAGE}/usr/sbin" \
+         "${INITRAMFS_STAGE}/usr/lib" \
+         "${INITRAMFS_STAGE}/dev" \
+         "${INITRAMFS_STAGE}/proc" \
+         "${INITRAMFS_STAGE}/sys" \
+         "${INITRAMFS_STAGE}/tmp" \
+         "${INITRAMFS_STAGE}/run" \
+         "${INITRAMFS_STAGE}/root" \
+         "${INITRAMFS_STAGE}/etc/udev/rules.d"
+ln -s usr/bin  "${INITRAMFS_STAGE}/bin"
+ln -s usr/sbin "${INITRAMFS_STAGE}/sbin"
+ln -s usr/lib  "${INITRAMFS_STAGE}/lib"
+ln -s usr/lib  "${INITRAMFS_STAGE}/lib64"
+
+# init script (PID 1)
+install -m 0755 "${BR2_EXTERNAL_COCOS_PATH}/board/rootfs-overlay/init" \
+    "${INITRAMFS_STAGE}/init"
+
+# Binaries required by the init script
+FDE_BINS="
+    bash
+    cryptsetup
+    veritysetup
+    mkfs.ext4
+    mount
+    umount
+    losetup
+    switch_root
+    dd
+    shred
+    tr
+    cut
+    grep
+    awk
+    cat
+    ls
+    cp
+    mkdir
+    readlink
+    dirname
+    lsblk
+    udevadm
+    blkid
+    rm
+"
+
+for BIN in ${FDE_BINS}; do
+    SRC="$(find "${TARGET_DIR}/usr/bin" "${TARGET_DIR}/usr/sbin" \
+               "${TARGET_DIR}/bin"      "${TARGET_DIR}/sbin" \
+               -name "${BIN}" \( -type f -o -type l \) 2>/dev/null | head -1)"
+    if [ -n "${SRC}" ]; then
+        cp -P "${SRC}" "${INITRAMFS_STAGE}/usr/bin/${BIN}"
+        chmod 0755 "${INITRAMFS_STAGE}/usr/bin/${BIN}" 2>/dev/null || true
+        # If this is a symlink, also copy the resolved target binary (e.g. busybox, coreutils, mke2fs)
+        # so that other applet symlinks pointing to the same target also work at runtime.
+        if [ -L "${SRC}" ]; then
+            REAL_SRC="$(readlink -f "${SRC}")"
+            REAL_NAME="$(basename "${REAL_SRC}")"
+            if [ -f "${REAL_SRC}" ] && [ ! -e "${INITRAMFS_STAGE}/usr/bin/${REAL_NAME}" ]; then
+                cp "${REAL_SRC}" "${INITRAMFS_STAGE}/usr/bin/${REAL_NAME}"
+                chmod 0755 "${INITRAMFS_STAGE}/usr/bin/${REAL_NAME}" 2>/dev/null || true
+            fi
+        fi
+    else
+        echo "[post-image] WARNING: ${BIN} not found in target, skipping"
+    fi
+done
+
+# sh symlink so #!/bin/sh in the init script resolves correctly
+ln -sf bash "${INITRAMFS_STAGE}/usr/bin/sh"
+
+# Shared libraries from usr/lib (TARGET_DIR uses merged-usr so lib → usr/lib)
+# Skip large runtimes that are only needed on the real root.
+find "${TARGET_DIR}/usr/lib" \( \
+        -path "*/python3*" -o \
+        -path "*/gcc*"     -o \
+        -path "*/wasmedge*" \
+    \) -prune -o \
+    \( -name "*.so" -o -name "*.so.*" \) -print | while read -r LIB; do
+    REL="${LIB#${TARGET_DIR}/usr/lib/}"
+    DEST="${INITRAMFS_STAGE}/usr/lib/${REL}"
+    mkdir -p "$(dirname "${DEST}")"
+    cp -P "${LIB}" "${DEST}"
+done
+
+# udev rules (needed for udevadm settle)
+if [ -d "${TARGET_DIR}/etc/udev" ]; then
+    cp -a "${TARGET_DIR}/etc/udev/." "${INITRAMFS_STAGE}/etc/udev/"
+fi
+
+# /dev seed nodes
+mknod -m 0600 "${INITRAMFS_STAGE}/dev/console" c 5 1 2>/dev/null || true
+mknod -m 0666 "${INITRAMFS_STAGE}/dev/null"    c 1 3 2>/dev/null || true
+
+echo "[post-image] Packing initramfs..."
+( cd "${INITRAMFS_STAGE}" && \
+    find . | cpio --quiet -o -H newc -R 0:0 | gzip -9 \
+    > "${BINARIES_DIR}/rootfs.cpio.gz" )
+echo "[post-image] rootfs.cpio.gz: $(du -sh "${BINARIES_DIR}/rootfs.cpio.gz" | cut -f1)"
+
+ROOTFS_IMAGE="${BINARIES_DIR}/rootfs.ext4"
+VERITY_IMAGE="${BINARIES_DIR}/rootfs.verity"
+ROOT_HASH_FILE="${BINARIES_DIR}/rootfs.roothash"
+VERITYSETUP_BIN="${HOST_DIR}/bin/veritysetup"
+
+if [ ! -x "${VERITYSETUP_BIN}" ]; then
+    VERITYSETUP_BIN="${HOST_DIR}/sbin/veritysetup"
+fi
+
+if [ ! -x "${VERITYSETUP_BIN}" ]; then
+    echo "[post-image] FATAL: host veritysetup not found at ${VERITYSETUP_BIN}"
+    exit 1
+fi
+
+echo "[post-image] Building dm-verity hash image..."
+rm -f "${VERITY_IMAGE}" "${ROOT_HASH_FILE}"
+truncate -s 256M "${VERITY_IMAGE}"
+VERITY_FORMAT_OUTPUT="$("${VERITYSETUP_BIN}" format "${ROOTFS_IMAGE}" "${VERITY_IMAGE}")" || {
+    echo "[post-image] FATAL: veritysetup format failed"
+    exit 1
+}
+
+ROOT_HASH="$(printf '%s\n' "${VERITY_FORMAT_OUTPUT}" | awk -F': ' '/^Root hash:/ {print $2}' | tr -d '[:space:]')"
+if [ -z "${ROOT_HASH}" ]; then
+    echo "[post-image] FATAL: failed to parse dm-verity root hash"
+    printf '%s\n' "${VERITY_FORMAT_OUTPUT}"
+    exit 1
+fi
+printf '%s\n' "${ROOT_HASH}" > "${ROOT_HASH_FILE}"
+echo "[post-image] dm-verity root hash: ${ROOT_HASH}"
+
+# Stage kernel and initramfs for the EFI partition.
+# Buildroot's GRUB2 package has already placed bootx64.efi at
+# ${BINARIES_DIR}/efi-part/EFI/BOOT/bootx64.efi; we add the kernel,
+# initramfs, and overwrite the default grub.cfg with our boot entry.
+echo "[post-image] Staging EFI partition files..."
+mkdir -p "${BINARIES_DIR}/efi-part/EFI/BOOT"
+cp "${BINARIES_DIR}/bzImage"        "${BINARIES_DIR}/efi-part/bzImage"
+cp "${BINARIES_DIR}/rootfs.cpio.gz" "${BINARIES_DIR}/efi-part/initrd.cpio.gz"
+
+cat > "${BINARIES_DIR}/efi-part/EFI/BOOT/grub.cfg" << GRUBCFG
+set default=0
+set timeout=0
+
+menuentry "Cocos" {
+    linux /bzImage console=ttyS0 roothash=${ROOT_HASH} systemd.verity=0 systemd.gpt_auto=0
+    initrd /initrd.cpio.gz
+}
+GRUBCFG
+
+# Regenerate bootx64.efi with --disable-shim-lock so GRUB can load the kernel
+# directly without requiring the shim bootloader (OVMF still verifies GRUB via
+# Secure Boot; shim is not needed when booting from a custom OVMF with own DB key).
+GRUB_CORE="$(ls -d "${BUILD_DIR}"/grub2-*/build-x86_64-efi/grub-core 2>/dev/null | head -1)"
+if [ -n "${GRUB_CORE}" ]; then
+    echo "[post-image] Regenerating bootx64.efi with --disable-shim-lock..."
+    "${HOST_DIR}/bin/grub-mkimage" \
+        -d "${GRUB_CORE}" \
+        -O x86_64-efi \
+        -o "${BINARIES_DIR}/efi-part/EFI/BOOT/bootx64.efi" \
+        -p "/EFI/BOOT" \
+        --disable-shim-lock \
+        boot linux echo normal part_gpt fat ls search || {
+        echo "[post-image] FATAL: grub-mkimage failed"
+        exit 1
+    }
+else
+    echo "[post-image] WARNING: GRUB core dir not found, skipping --disable-shim-lock rebuild"
+fi
+
+# Sign GRUB and kernel for UEFI Secure Boot.
+# Keys are resolved in order: env var → board/secure-boot/ defaults.
+SB_KEY="${SB_KEY:-${COCOS_BOARD_DIR}/secure-boot/db.key}"
+SB_CERT="${SB_CERT:-${COCOS_BOARD_DIR}/secure-boot/db.crt}"
+if [ -f "${SB_KEY}" ] && [ -f "${SB_CERT}" ]; then
+    echo "[post-image] Signing EFI binaries for Secure Boot..."
+    sbsign --key "${SB_KEY}" --cert "${SB_CERT}" \
+        --output "${BINARIES_DIR}/efi-part/EFI/BOOT/bootx64.efi" \
+        "${BINARIES_DIR}/efi-part/EFI/BOOT/bootx64.efi" || {
+        echo "[post-image] FATAL: Failed to sign bootx64.efi"
+        exit 1
+    }
+    sbsign --key "${SB_KEY}" --cert "${SB_CERT}" \
+        --output "${BINARIES_DIR}/efi-part/bzImage" \
+        "${BINARIES_DIR}/efi-part/bzImage" || {
+        echo "[post-image] FATAL: Failed to sign bzImage"
+        exit 1
+    }
+    echo "[post-image] Secure Boot signing complete"
+else
+    echo "[post-image] WARNING: Secure Boot keys not found — EFI binaries are unsigned"
+    echo "[post-image]   Default location: ${COCOS_BOARD_DIR}/secure-boot/db.key + db.crt"
+    echo "[post-image]   Override:         SB_KEY=/path/to/db.key SB_CERT=/path/to/db.crt make"
+fi
+
+GENIMAGE_CFG="${COCOS_BOARD_DIR}/genimage.cfg"
+if [ -f "${GENIMAGE_CFG}" ]; then
+    GENIMAGE_TMP="${BUILD_DIR}/genimage.tmp"
+    rm -rf "${GENIMAGE_TMP}"
+    genimage \
+        --rootpath "${TARGET_DIR}" \
+        --tmppath "${GENIMAGE_TMP}" \
+        --inputpath "${BINARIES_DIR}" \
+        --outputpath "${BINARIES_DIR}" \
+        --config "${GENIMAGE_CFG}"
+fi
+
+if [[ "${DEFCONFIG_NAME}" =~ ^"cocos_*" ]]; then
+    # Not a Qemu defconfig, can't test.
+    exit 0
+fi
+
+# Search for "# qemu_*_defconfig" tag in all readme.txt files.
+# Qemu command line on multilines using back slash are accepted.
+# shellcheck disable=SC2086 # glob over each readme file
+QEMU_CMD_LINE="$(sed -r ':a; /\\$/N; s/\\\n//; s/\t/ /; ta; /# '"${DEFCONFIG_NAME}"'$/!d; s/#.*//' ${README_FILES})"
+
+if [ -z "${QEMU_CMD_LINE}" ]; then
+    # No Qemu cmd line found, can't test.
+    exit 0
+fi
+
+# Remove output/images path since the script will be in
+# the same directory as the kernel and the rootfs images.
+QEMU_CMD_LINE="${QEMU_CMD_LINE//output\/images\//}"
+
+# Remove -serial stdio if present, keep it as default args
+DEFAULT_ARGS="$(sed -r -e '/-serial stdio/!d; s/.*(-serial stdio).*/\1/' <<<"${QEMU_CMD_LINE}")"
+QEMU_CMD_LINE="${QEMU_CMD_LINE//-serial stdio/}"
+
+# Remove any string before qemu-system-*
+QEMU_CMD_LINE="$(sed -r -e 's/^.*(qemu-system-)/\1/' <<<"${QEMU_CMD_LINE}")"
+
+# Disable graphical output and redirect serial I/Os to console
+case ${DEFCONFIG_NAME} in
+  (qemu_sh4eb_r2d_defconfig|qemu_sh4_r2d_defconfig)
+    # Special case for SH4
+    SERIAL_ARGS="-serial stdio -display none"
+    ;;
+  (*)
+    SERIAL_ARGS="-nographic"
+    ;;
+esac
+
+sed -e "s|@SERIAL_ARGS@|${SERIAL_ARGS}|g" \
+    -e "s|@DEFAULT_ARGS@|${DEFAULT_ARGS}|g" \
+    -e "s|@QEMU_CMD_LINE@|${QEMU_CMD_LINE}|g" \
+    -e "s|@HOST_DIR@|${HOST_DIR}|g" \
+    <"${COCOS_BOARD_DIR}/start-qemu.sh.in" \
+    >"${START_QEMU_SCRIPT}"
+chmod +x "${START_QEMU_SCRIPT}"
@@ -0,0 +1,7 @@
+Run the emulation with:
+
+  qemu-system-x86_64 -M pc -kernel output/images/bzImage -drive file=output/images/rootfs.ext2,if=virtio,format=raw -append "rootwait root=/dev/vda console=tty1 console=ttyS0" -serial stdio -net nic,model=virtio -net user # cocos_defconfig
+
+Optionally add -smp N to emulate a SMP system with N CPUs.
+
+The login prompt will appear in the graphical window.
@@ -0,0 +1,3 @@
+# Private key must not be committed
+db.key
+db.crt
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+BINARIES_DIR="${0%/*}/"
+# shellcheck disable=SC2164
+cd "${BINARIES_DIR}"
+
+mode_serial=false
+mode_sys_qemu=false
+while [ "$1" ]; do
+    case "$1" in
+    --serial-only|serial-only) mode_serial=true; shift;;
+    --use-system-qemu) mode_sys_qemu=true; shift;;
+    --) shift; break;;
+    *) echo "unknown option: $1" >&2; exit 1;;
+    esac
+done
+
+if ${mode_serial}; then
+    EXTRA_ARGS='@SERIAL_ARGS@'
+else
+    EXTRA_ARGS='@DEFAULT_ARGS@'
+fi
+
+if ! ${mode_sys_qemu}; then
+    export PATH="@HOST_DIR@/bin:${PATH}"
+fi
+
+exec @QEMU_CMD_LINE@ ${EXTRA_ARGS} "$@"
@@ -0,0 +1,7 @@
+# Root is mounted read-only by the initramfs through dm-verity.
+# /cocos, /var, /tmp, and bind mounts are set up by the initramfs init script.
+/dev/mapper/root_verity  /        ext4  ro,defaults          0 0
+
+# 9P virtio shares — provided by the hypervisor, optional (nofail)
+certs_share  /etc/certs   9p  trans=virtio,version=9p2000.L,cache=mmap,nofail  0 0
+env_share    /etc/cocos   9p  trans=virtio,version=9p2000.L,cache=mmap,nofail  0 0
@@ -0,0 +1,7 @@
+{
+  "key-providers": {
+    "attestation-agent": {
+      "grpc": "127.0.0.1:50011"
+    }
+  }
+}
@@ -0,0 +1,265 @@
+#!/bin/sh
+
+export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+
+if (exec 0</dev/console) 2>/dev/null; then
+    exec 0</dev/console
+    exec 1>/dev/console
+    exec 2>/dev/console
+fi
+
+echo "Welcome to the Cocos FDE test VM initramfs!"
+echo "This is a minimal initramfs environment used for testing the FDE provisioning flow."
+echo "If you see this message, the initramfs was loaded and executed successfully."
+echo "The initramfs will now attempt to provision the disk and mount the real root filesystem."
+echo "If any step fails, it will drop to a shell for debugging."
+
+[ -d /dev ] || mkdir -m 0755 /dev
+[ -d /etc ] || mkdir -m 0755 /etc
+[ -d /root ] || mkdir -m 0700 /root
+[ -d /run ] || mkdir -m 0755 /run
+[ -d /sys ] || mkdir /sys
+[ -d /proc ] || mkdir /proc
+[ -d /tmp ] || mkdir /tmp
+
+if [ -L /etc/resolv.conf ]; then
+    RESOLV_TARGET="$(readlink /etc/resolv.conf)"
+    case "$RESOLV_TARGET" in
+        /*)
+            RESOLV_PATH="$RESOLV_TARGET"
+            ;;
+        *)
+            RESOLV_PATH="/etc/$RESOLV_TARGET"
+            ;;
+    esac
+
+    mkdir -p "$(dirname "$RESOLV_PATH")"
+    [ -e "$RESOLV_PATH" ] || : > "$RESOLV_PATH"
+else
+    [ -e /etc/resolv.conf ] || : > /etc/resolv.conf
+fi
+
+mount -t sysfs -o nodev,noexec,nosuid sysfs /sys
+mount -t proc -o nodev,noexec,nosuid proc /proc
+
+mkdir -p /sys/kernel/config
+if ! grep -q ' /sys/kernel/config ' /proc/mounts; then
+    mount -t configfs configfs /sys/kernel/config 2>/dev/null || true
+fi
+
+mount -t devtmpfs -o nosuid,mode=0755 udev /dev
+mkdir /dev/pts
+mount -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts || true
+
+MNT_DIR=/root
+BASE=$(pwd)
+
+DST=/dev/sda
+ROOTFS_TYPE="ext4"
+ROOT_VERITY_MAP=root_verity
+ROOT_VERITY_MAPPER="/dev/mapper/$ROOT_VERITY_MAP"
+COCOS_MOUNT=/cocos
+COCOS_MAP=cocos_crypt
+COCOS_MAPPER="/dev/mapper/$COCOS_MAP"
+LUKS_PARAMS="--cipher aes-gcm-random --integrity aead"
+
+settle_devices() {
+    echo "[init] Waiting for devices to settle..."
+    if command -v udevadm >/dev/null 2>&1; then
+        udevadm settle --timeout=10 || sleep 2
+    else
+        sleep 2
+    fi
+}
+
+wipe_file() {
+    file_path="$1"
+    if [ -z "$file_path" ] || [ ! -e "$file_path" ]; then
+        return 0
+    fi
+
+    shred -vfz -n 3 "$file_path" 2>/dev/null || dd if=/dev/zero of="$file_path" bs=64 count=1
+    rm -f "$file_path"
+}
+
+partition_path() {
+    disk="$1"
+    partition="$2"
+
+    case "$disk" in
+        *[0-9])
+            printf '%sp%s\n' "$disk" "$partition"
+            ;;
+        *)
+            printf '%s%s\n' "$disk" "$partition"
+            ;;
+    esac
+}
+
+append_9p_entry() {
+    pattern="$1"
+    default_entry="$2"
+    existing_entry=""
+
+    if [ -f "$FSTAB_BAK" ]; then
+        existing_entry="$(grep -E "$pattern" "$FSTAB_BAK" | head -n 1 || true)"
+    fi
+
+    if [ -n "$existing_entry" ]; then
+        printf '%s\n' "$existing_entry" >> "$FSTAB"
+    else
+        printf '%s\n' "$default_entry" >> "$FSTAB"
+    fi
+}
+
+cmdline_arg() {
+    key="$1"
+    for arg in $(cat /proc/cmdline); do
+        case "$arg" in
+            "$key="*)
+                printf '%s\n' "${arg#*=}"
+                return 0
+                ;;
+        esac
+    done
+    return 1
+}
+
+echo "[init] Starting disk provisioning..."
+ROOT_PART="$(partition_path "$DST" 2)"
+VERITY_PART="$(partition_path "$DST" 3)"
+COCOS_PART="$(partition_path "$DST" 4)"
+ROOT_HASH="$(cmdline_arg roothash)"
+
+if [ -z "$ROOT_HASH" ]; then
+    echo "[init] FATAL: Missing roothash= on kernel command line"
+    exec /bin/sh
+fi
+
+settle_devices
+
+for part in "$ROOT_PART" "$VERITY_PART" "$COCOS_PART"; do
+    if [ ! -b "$part" ]; then
+        echo "[init] FATAL: Could not find partition $part"
+        echo "[init] Available block devices:"
+        lsblk || ls -la /dev/ || true
+        echo "[init] Dropping to shell."
+        exec /bin/sh
+    fi
+done
+
+echo "[init] Opening dm-verity root mapping..."
+veritysetup open "$ROOT_PART" "$ROOT_VERITY_MAP" "$VERITY_PART" "$ROOT_HASH" || {
+    echo "[init] FATAL: Failed to open dm-verity mapping for root"
+    exec /bin/sh
+}
+
+echo "[init] Mounting root at $MNT_DIR (read-only)..."
+mount -o ro -t "$ROOTFS_TYPE" "$ROOT_VERITY_MAPPER" "$MNT_DIR" || {
+    echo "[init] FATAL: Failed to mount verity root"
+    veritysetup close "$ROOT_VERITY_MAP" 2>/dev/null || true
+    exec /bin/sh
+}
+
+echo "[init] Generating ephemeral key for $COCOS_MOUNT..."
+dd if=/dev/urandom of=kk.bin bs=64 count=1 || {
+    echo "[init] FATAL: Failed to generate encryption key"
+    umount "$MNT_DIR" 2>/dev/null || true
+    exec /bin/sh
+}
+KK_BIN=$BASE/kk.bin
+
+cryptsetup luksFormat "$COCOS_PART" --type luks2 $LUKS_PARAMS --key-file="$KK_BIN" -q || {
+    echo "[init] FATAL: LUKS format failed"
+    umount "$MNT_DIR" 2>/dev/null || true
+    veritysetup close "$ROOT_VERITY_MAP" 2>/dev/null || true
+    wipe_file "$KK_BIN"
+    exec /bin/sh
+}
+
+cryptsetup open "$COCOS_PART" "$COCOS_MAP" --key-file="$KK_BIN" || {
+    echo "[init] FATAL: Failed to open LUKS container for $COCOS_MOUNT"
+    umount "$MNT_DIR" 2>/dev/null || true
+    veritysetup close "$ROOT_VERITY_MAP" 2>/dev/null || true
+    wipe_file "$KK_BIN"
+    exec /bin/sh
+}
+
+mkfs.ext4 -F -m 0 "$COCOS_MAPPER" >/dev/null || {
+    echo "[init] FATAL: Failed to create ext4 filesystem for $COCOS_MOUNT"
+    cryptsetup close "$COCOS_MAP" 2>/dev/null || true
+    umount "$MNT_DIR" 2>/dev/null || true
+    veritysetup close "$ROOT_VERITY_MAP" 2>/dev/null || true
+    wipe_file "$KK_BIN"
+    exec /bin/sh
+}
+
+echo "[init] Mounting encrypted $COCOS_MOUNT..."
+mkdir -p "$MNT_DIR$COCOS_MOUNT"
+mount -t ext4 "$COCOS_MAPPER" "$MNT_DIR$COCOS_MOUNT" || {
+    echo "[init] FATAL: Failed to mount encrypted $COCOS_MOUNT filesystem"
+    cryptsetup close "$COCOS_MAP" 2>/dev/null || true
+    umount "$MNT_DIR" 2>/dev/null || true
+    veritysetup close "$ROOT_VERITY_MAP" 2>/dev/null || true
+    wipe_file "$KK_BIN"
+    exec /bin/sh
+}
+
+mkdir -p \
+    "$MNT_DIR$COCOS_MOUNT/.cache/oci" \
+    "$MNT_DIR$COCOS_MOUNT/datasets" \
+    "$MNT_DIR$COCOS_MOUNT/docker" \
+    "$MNT_DIR$COCOS_MOUNT/cocos_init"
+
+# The root is read-only; provide tmpfs for writable system directories.
+mount -t tmpfs tmpfs "$MNT_DIR/tmp"
+mount -t tmpfs -o mode=0755 tmpfs "$MNT_DIR/var"
+
+# Bind Docker's data root onto /cocos so large images don't exhaust RAM.
+mkdir -p "$MNT_DIR/var/lib/docker"
+mount --bind "$MNT_DIR$COCOS_MOUNT/docker" "$MNT_DIR/var/lib/docker"
+
+# /cocos_init is on the read-only root; shadow it with a writable
+# copy on /cocos so agent setup scripts can write state alongside the scripts.
+if [ -d "$MNT_DIR/cocos_init" ]; then
+    cp -a "$MNT_DIR/cocos_init/." "$MNT_DIR$COCOS_MOUNT/cocos_init/" 2>/dev/null || true
+    mount --bind "$MNT_DIR$COCOS_MOUNT/cocos_init" "$MNT_DIR/cocos_init" || true
+fi
+
+mount --move /proc $MNT_DIR/proc
+mount --move /sys $MNT_DIR/sys
+
+FSTAB="$MNT_DIR/etc/fstab"
+FSTAB_BAK="$MNT_DIR/etc/fstab.bak"
+
+mkdir -p "$MNT_DIR/etc/certs" "$MNT_DIR/etc/cocos" 2>/dev/null || true
+
+if [ -f "$FSTAB" ]; then
+    mv "$FSTAB" "$FSTAB_BAK"
+fi
+
+cat > "$FSTAB" << EOF
+# Generated by init script
+$ROOT_VERITY_MAPPER / $ROOTFS_TYPE ro,defaults 0 0
+EOF
+
+append_9p_entry \
+    '^certs_share[[:space:]]+/etc/certs[[:space:]]+9p([[:space:]]|$)' \
+    'certs_share /etc/certs 9p trans=virtio,version=9p2000.L,cache=mmap,nofail 0 0'
+
+append_9p_entry \
+    '^env_share[[:space:]]+/etc/cocos[[:space:]]+9p([[:space:]]|$)' \
+    'env_share /etc/cocos 9p trans=virtio,version=9p2000.L,cache=mmap,nofail 0 0'
+
+printf '%s\n' '# /cocos is mounted by the FDE initramfs using an ephemeral LUKS key.' >> "$FSTAB"
+
+# Securely wipe the encryption key before switching root.
+echo "[init] Securely wiping the $COCOS_MOUNT encryption key..."
+wipe_file "$KK_BIN"
+
+echo "[init] Switching to real root..."
+exec switch_root $MNT_DIR/ /sbin/init
+
+# If switch_root somehow returns:
+echo "[init] switch_root failed, dropping to shell"
+exec /bin/sh
@@ -0,0 +1,3 @@
+[Unit]
+RequiresMountsFor=/etc/cocos /etc/certs
+
@@ -0,0 +1,3 @@
+[Unit]
+RequiresMountsFor=/etc/cocos
+
@@ -0,0 +1,3 @@
+[Unit]
+RequiresMountsFor=/etc/cocos
+
@@ -0,0 +1,3 @@
+[Unit]
+RequiresMountsFor=/etc/cocos
+
@@ -0,0 +1,2 @@
+d /var/log/cocos 0755 root root -
+d /run/cocos 0755 root root -
@@ -0,0 +1,117 @@
+# Architecture
+BR2_x86_64=y
+
+# System
+BR2_TARGET_GENERIC_HOSTNAME="cocos"
+BR2_TARGET_GENERIC_ISSUE="Welcome to Cocos"
+BR2_PACKAGE_DHCP=y
+BR2_PACKAGE_DHCP_CLIENT=y
+BR2_INIT_SYSTEMD=y
+BR2_SYSTEM_BIN_SH_BASH=y
+
+# Filesystem
+# BR2_TARGET_ROOTFS_TAR is not set
+# Initramfs (rootfs.cpio.gz) is built by post-image.sh from only the FDE tools,
+# not from the full target rootfs.  The full rootfs goes to rootfs.ext4 (disk image).
+BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_COCOS_PATH)/board/rootfs-overlay"
+
+# Patches for existing Buildroot packages
+BR2_GLOBAL_PATCH_DIR="$(BR2_EXTERNAL_COCOS_PATH)/patches"
+
+# Bootloader
+BR2_TARGET_GRUB2=y
+BR2_TARGET_GRUB2_X86_64_EFI=y
+BR2_TARGET_GRUB2_BUILTIN_MODULES_EFI="boot linux echo normal part_gpt fat ls search"
+
+# Disk image
+BR2_TARGET_ROOTFS_EXT2=y
+BR2_TARGET_ROOTFS_EXT2_4=y
+BR2_TARGET_ROOTFS_EXT2_SIZE="10G"
+BR2_PACKAGE_HOST_GENIMAGE=y
+BR2_PACKAGE_HOST_CRYPTSETUP=y
+
+# Image
+BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_COCOS_PATH)/board/cocos/post-build.sh"
+
+# Image
+BR2_ROOTFS_POST_IMAGE_SCRIPT="$(BR2_EXTERNAL_COCOS_PATH)/board/cocos/post-image.sh"
+BR2_ROOTFS_POST_SCRIPT_ARGS="$(BR2_DEFCONFIG)"
+
+# Linux headers same as kernel
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_6_11=y
+BR2_TOOLCHAIN_HEADERS_LATEST=y
+BR2_TOOLCHAIN_HEADERS_AT_LEAST="6.11-rc7"
+
+# Kernel
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/coconut-svsm/linux.git"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="svsm"
+BR2_LINUX_KERNEL_VERSION="svsm"
+BR2_LINUX_KERNEL_PATCH=""
+BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
+BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL_COCOS_PATH)/board/cocos/linux.config"
+BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF=y
+
+# host-qemu for gitlab testing
+BR2_PACKAGE_HOST_QEMU=y
+BR2_PACKAGE_HOST_QEMU_SYSTEM_MODE=y
+
+# Python
+BR2_PACKAGE_PYTHON3=y
+BR2_PACKAGE_PYTHON_PIP=y
+BR2_PACKAGE_BZIP2=y
+BR2_PACKAGE_XZ=y
+BR2_PACKAGE_ZIP=y
+BR2_PACKAGE_PYTHON3_ZLIB=y
+BR2_PACKAGE_PYTHON3_XZ=y
+BR2_PACKAGE_PYTHON3_BZIP2=y
+BR2_INSTALL_LIBSTDCPP=y
+BR2_TOOLCHAIN_BUILDROOT_CXX=y
+BR2_PACKAGE_HOST_GCC_TARGET=y
+BR2_TOOLCHAIN_BUILDROOT_LIBSTDCPP=y
+BR2_PACKAGE_GCC=y
+BR2_PACKAGE_GCC_TARGET=y
+BR2_PACKAGE_LIBSTDCPP=y
+
+# FDE
+BR2_PACKAGE_NBD=y
+BR2_PACKAGE_NBD_CLIENT=y
+BR2_PACKAGE_CRYPTSETUP=y
+BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_EUDEV=y
+BR2_PACKAGE_EUDEV=y
+BR2_PACKAGE_HAS_UDEV=y
+BR2_PACKAGE_MULTIPATH_TOOLS=y
+BR2_PACKAGE_UTIL_LINUX_BINARIES=y
+BR2_PACKAGE_E2FSPROGS=y
+BR2_LINUX_KERNEL_NEEDS_HOST_PAHOLE=y
+
+# TPM2
+BR2_PACKAGE_TPM2_TOOLS=y
+BR2_PACKAGE_COREUTILS=y
+
+# Docker
+BR2_PACKAGE_LIBSECCOMP_ARCH_SUPPORTS=y
+BR2_PACKAGE_LIBSECCOMP=y
+BR2_PACKAGE_CA_CERTIFICATES=y
+BR2_PACKAGE_DOCKER_CLI=y
+BR2_PACKAGE_DOCKER_COMPOSE=y
+BR2_PACKAGE_DOCKER_ENGINE=y
+BR2_PACKAGE_CONTAINERD=y
+BR2_PACKAGE_RUNC=y
+BR2_PACKAGE_IPTABLES=y
+
+# Skopeo for OCI image handling with CoCo Keyprovider
+BR2_PACKAGE_SKOPEO=y
+BR2_PACKAGE_GPGME=y
+BR2_PACKAGE_LVM2=y
+BR2_PACKAGE_LVM2_STANDARD_INSTALL=y
+BR2_PACKAGE_9PFS=y
+
+# Host tools
+BR2_PACKAGE_HOST_RUSTC=y
+BR2_PACKAGE_HOST_RUST_BIN=y
+
+# Cocos AI Packages
+BR2_PACKAGE_AGENT=y
+# BR2_PACKAGE_CC_ATTESTATION_AGENT is not set
@@ -0,0 +1,2 @@
+name: COCOS
+desc: External buildroot tree for Cocos AI
@@ -0,0 +1 @@
+include $(sort $(wildcard $(BR2_EXTERNAL_COCOS_PATH)/package/*/*.mk))
@@ -0,0 +1,13 @@
+config BR2_PACKAGE_AGENT
+	bool "agent"
+	default y
+	select BR2_PACKAGE_ATTESTATION_SERVICE
+	select BR2_PACKAGE_LOG_FORWARDER
+	select BR2_PACKAGE_COMPUTATION_RUNNER
+	select BR2_PACKAGE_INGRESS_PROXY
+	select BR2_PACKAGE_EGRESS_PROXY
+	help
+	  Confidential Computing Agent is a state machine capable of
+	  receiving datasets and algorithm, running computations, and
+	  fetching the attestation report from within the
+	  Confidential VM.
@@ -0,0 +1,27 @@
+################################################################################
+#
+# Cocos AI Agent
+#
+################################################################################
+
+AGENT_VERSION = main
+AGENT_SITE = $(call github,ultravioletrs,cocos,$(AGENT_VERSION))
+
+define AGENT_BUILD_CMDS
+	$(MAKE) -C $(@D) agent EMBED_ENABLED=$(AGENT_EMBED_ENABLED)
+endef
+
+define AGENT_INSTALL_TARGET_CMDS
+	mkdir -p $(TARGET_DIR)/cocos/
+	mkdir -p $(TARGET_DIR)/var/log/cocos
+	mkdir -p $(TARGET_DIR)/cocos_init/
+	$(INSTALL) -D -m 0750 $(@D)/build/cocos-agent $(TARGET_DIR)/bin
+endef
+
+define AGENT_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0640 $(@D)/init/systemd/cocos-agent.service $(TARGET_DIR)/usr/lib/systemd/system/cocos-agent.service
+	$(INSTALL) -D -m 0750 $(@D)/init/systemd/agent_setup.sh $(TARGET_DIR)/cocos_init/agent_setup.sh
+	$(INSTALL) -D -m 0750 $(@D)/init/systemd/agent_start_script.sh $(TARGET_DIR)/cocos_init/agent_start_script.sh
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,11 @@
+config BR2_PACKAGE_ATTESTATION_SERVICE
+	bool
+	default y
+	help
+	  Cocos AI attestation service that generates EAT tokens
+	  for TEE attestation (SNP, TDX, vTPM, Azure).
+	  
+	  This service can optionally use the Confidential Containers
+	  attestation-agent as a backend provider via gRPC.
+	  
+	  https://github.com/ultravioletrs/cocos
@@ -0,0 +1,34 @@
+################################################################################
+#
+# attestation-service
+#
+################################################################################
+
+ATTESTATION_SERVICE_VERSION = main
+ATTESTATION_SERVICE_SITE = $(call github,ultravioletrs,cocos,$(ATTESTATION_SERVICE_VERSION))
+
+define ATTESTATION_SERVICE_BUILD_CMDS
+	$(MAKE) -C $(@D) attestation-service
+endef
+
+define ATTESTATION_SERVICE_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0755 $(@D)/build/cocos-attestation-service $(TARGET_DIR)/usr/bin/attestation-service
+endef
+
+ifeq ($(BR2_PACKAGE_CC_ATTESTATION_AGENT),y)
+define ATTESTATION_SERVICE_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0640 $(@D)/init/systemd/attestation-service.service $(TARGET_DIR)/usr/lib/systemd/system/attestation-service.service
+	$(INSTALL) -D -m 0750 $(@D)/init/systemd/attestation_setup.sh $(TARGET_DIR)/cocos_init/attestation_setup.sh
+	# CC attestation agent is already enabled by default
+endef
+else
+define ATTESTATION_SERVICE_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0640 $(@D)/init/systemd/attestation-service.service $(TARGET_DIR)/usr/lib/systemd/system/attestation-service.service
+	$(INSTALL) -D -m 0750 $(@D)/init/systemd/attestation_setup.sh $(TARGET_DIR)/cocos_init/attestation_setup.sh
+	# Disable CC attestation agent backend if not selected
+	sed -i 's/USE_CC_ATTESTATION_AGENT=true/USE_CC_ATTESTATION_AGENT=false/' $(TARGET_DIR)/usr/lib/systemd/system/attestation-service.service
+	sed -i '/Wants=attestation-agent.service/d' $(TARGET_DIR)/usr/lib/systemd/system/attestation-service.service
+endef
+endif
+
+$(eval $(generic-package))
@@ -0,0 +1,28 @@
+config BR2_PACKAGE_CC_ATTESTATION_AGENT
+	bool "cc-attestation-agent"
+	select BR2_PACKAGE_PROTOBUF
+	select BR2_PACKAGE_OPENSSL
+	select BR2_PACKAGE_TPM2_TSS
+	help
+	  Confidential Containers attestation-agent for TEE attestation.
+	  
+	  Optional backend for the Cocos AI attestation service that
+	  provides KBS protocol support for remote attestation and
+	  encrypted secret provisioning.
+	  
+	  https://github.com/confidential-containers/guest-components
+
+if BR2_PACKAGE_CC_ATTESTATION_AGENT
+
+config BR2_PACKAGE_CC_ATTESTATION_AGENT_KBS_URL
+	string "Default KBS URL (optional)"
+	default ""
+	help
+	  Optional default KBS (Key Broker Service) URL for remote
+	  attestation and secret provisioning.
+	  
+	  Leave empty to operate in local attestation mode only.
+	  
+	  Example: https://kbs.example.com:8080
+
+endif
@@ -0,0 +1,5 @@
+#!/bin/bash
+# Setup permissions for attestation socket directory
+
+mkdir -p /run/cocos
+chmod 755 /run/cocos
@@ -0,0 +1,37 @@
+################################################################################
+#
+# cc-attestation-agent
+#
+################################################################################
+
+CC_ATTESTATION_AGENT_VERSION = mvp-runner
+CC_ATTESTATION_AGENT_SITE = $(call github,rodneyosodo,guest-components,$(CC_ATTESTATION_AGENT_VERSION))
+CC_ATTESTATION_AGENT_LICENSE = Apache-2.0
+CC_ATTESTATION_AGENT_LICENSE_FILES = LICENSE
+
+CC_ATTESTATION_AGENT_DEPENDENCIES = host-rustc openssl protobuf tpm2-tss
+
+# Build the attestation-agent from the guest-components repository with gRPC support
+define CC_ATTESTATION_AGENT_BUILD_CMDS
+	cd $(@D)/attestation-agent && \
+	$(TARGET_MAKE_ENV) \
+	CARGO_HOME=$(@D)/.cargo \
+	make ATTESTER=all-attesters ttrpc=false
+endef
+
+define CC_ATTESTATION_AGENT_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0755 \
+		$(@D)/target/$(RUSTC_TARGET_NAME)/release/attestation-agent \
+		$(TARGET_DIR)/usr/bin/attestation-agent
+endef
+
+define CC_ATTESTATION_AGENT_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0644 \
+		$(BR2_EXTERNAL_COCOS_PATH)/package/cc-attestation-agent/cc-attestation-agent.service \
+		$(TARGET_DIR)/usr/lib/systemd/system/attestation-agent.service
+	$(INSTALL) -D -m 0750 \
+		$(BR2_EXTERNAL_COCOS_PATH)/package/cc-attestation-agent/cc-attestation-agent-setup.sh \
+		$(TARGET_DIR)/cocos_init/attestation_setup.sh
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,13 @@
+[Unit]
+Description=Confidential Containers Attestation Agent (gRPC)
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/attestation-agent --attestation_sock 127.0.0.1:50002
+Restart=always
+RestartSec=5
+Environment=RUST_LOG=info
+
+[Install]
+WantedBy=multi-user.target
@@ -0,0 +1,11 @@
+config BR2_PACKAGE_COCO_KEYPROVIDER
+	bool "coco-keyprovider"
+	depends on BR2_PACKAGE_HOST_RUSTC_ARCH_SUPPORTS
+	select BR2_PACKAGE_HOST_RUSTC
+	help
+	  CoCo Keyprovider is a keyprovider tool for generating and
+	  decrypting CoCo-compatible encrypted images. It implements
+	  the ocicrypt keyprovider protocol to decrypt OCI image layers
+	  using the Key Broker Service (KBS).
+
+	  https://github.com/confidential-containers/guest-components
@@ -0,0 +1,28 @@
+#!/bin/sh
+set -e
+
+# Read kernel command line
+CMDLINE=$(cat /proc/cmdline)
+
+# Extract agent.aa_kbc_params value
+# Format: agent.aa_kbc_params=cc_kbc::URL
+PARAMS=$(echo "$CMDLINE" | tr ' ' '\n' | grep '^agent.aa_kbc_params=' | cut -d= -f2-)
+
+if [ -n "$PARAMS" ]; then
+    # Extract URL part (after ::)
+    KBS_URL="${PARAMS#*::}"
+    if [ -n "$KBS_URL" ]; then
+        echo "[coco-keyprovider-setup] Detected KBS URL from kernel cmdline: $KBS_URL"
+        KBS_ARG="--kbs $KBS_URL"
+    fi
+else
+    echo "[coco-keyprovider-setup] No agent.aa_kbc_params found in kernel cmdline. Starting without --kbs."
+fi
+
+# COCO_KP_SOCKET is set by EnvironmentFile in .service
+if [ -z "$COCO_KP_SOCKET" ]; then
+    COCO_KP_SOCKET="127.0.0.1:50011"
+fi
+
+echo "[coco-keyprovider-setup] Starting coco_keyprovider listening on $COCO_KP_SOCKET $KBS_ARG"
+exec /usr/local/bin/coco_keyprovider --socket "$COCO_KP_SOCKET" $KBS_ARG
@@ -0,0 +1,3 @@
+# CoCo Keyprovider Environment Variables
+COCO_KP_SOCKET=127.0.0.1:50011
+RUST_LOG=info
@@ -0,0 +1,34 @@
+################################################################################
+#
+# coco-keyprovider
+#
+################################################################################
+
+COCO_KEYPROVIDER_VERSION = mvp-runner
+COCO_KEYPROVIDER_SITE = $(call github,rodneyosodo,guest-components,$(COCO_KEYPROVIDER_VERSION))
+COCO_KEYPROVIDER_LICENSE = Apache-2.0
+COCO_KEYPROVIDER_LICENSE_FILES = LICENSE
+
+COCO_KEYPROVIDER_DEPENDENCIES = host-rustc
+
+define COCO_KEYPROVIDER_BUILD_CMDS
+	cd $(@D)/attestation-agent/coco_keyprovider && \
+	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) \
+	CARGO_HOME=$(HOST_DIR)/share/cargo \
+	cargo build --release --target=$(RUSTC_TARGET_NAME)
+endef
+
+define COCO_KEYPROVIDER_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0755 $(@D)/target/$(RUSTC_TARGET_NAME)/release/coco_keyprovider \
+		$(TARGET_DIR)/usr/local/bin/coco_keyprovider
+	$(INSTALL) -D -m 0755 $(BR2_EXTERNAL_COCOS_PATH)/package/coco-keyprovider/coco-keyprovider-setup.sh \
+		$(TARGET_DIR)/usr/local/bin/coco-keyprovider-setup.sh
+	$(INSTALL) -D -m 0644 $(BR2_EXTERNAL_COCOS_PATH)/package/coco-keyprovider/coco-keyprovider.service \
+		$(TARGET_DIR)/etc/systemd/system/coco-keyprovider.service
+	$(INSTALL) -D -m 0644 $(BR2_EXTERNAL_COCOS_PATH)/package/coco-keyprovider/coco-keyprovider.default \
+		$(TARGET_DIR)/etc/default/coco-keyprovider
+	mkdir -p $(TARGET_DIR)/etc
+	echo '{"key-providers": {"attestation-agent": {"grpc": "127.0.0.1:50011"}}}' > $(TARGET_DIR)/etc/ocicrypt_keyprovider.conf
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,25 @@
+[Unit]
+Description=CoCo Keyprovider for Confidential Containers
+Documentation=https://github.com/confidential-containers/guest-components
+After=network-online.target attestation-agent.service
+Wants=network-online.target
+Requires=attestation-agent.service
+
+[Service]
+Type=simple
+EnvironmentFile=/etc/default/coco-keyprovider
+RuntimeDirectory=coco-keyprovider
+ExecStart=/usr/local/bin/coco-keyprovider-setup.sh
+Restart=on-failure
+RestartSec=5s
+StandardOutput=journal
+StandardError=journal
+
+# Security hardening
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+
+[Install]
+WantedBy=multi-user.target
@@ -0,0 +1,5 @@
+config BR2_PACKAGE_COMPUTATION_RUNNER
+	bool "computation-runner"
+	select BR2_PACKAGE_LOG_FORWARDER
+	help
+	  Cocos AI Computation Runner service.
@@ -0,0 +1,22 @@
+################################################################################
+#
+# computation-runner
+#
+################################################################################
+
+COMPUTATION_RUNNER_VERSION = main
+COMPUTATION_RUNNER_SITE = $(call github,ultravioletrs,cocos,$(COMPUTATION_RUNNER_VERSION))
+
+define COMPUTATION_RUNNER_BUILD_CMDS
+	$(MAKE) -C $(@D) computation-runner
+endef
+
+define COMPUTATION_RUNNER_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0750 $(@D)/build/cocos-computation-runner $(TARGET_DIR)/usr/bin/computation-runner
+endef
+
+define COMPUTATION_RUNNER_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0640 $(@D)/init/systemd/computation-runner.service $(TARGET_DIR)/usr/lib/systemd/system/computation-runner.service
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,6 @@
+config BR2_PACKAGE_EGRESS_PROXY
+	bool "egress-proxy"
+	help
+	  Cocos AI Egress Proxy Service.
+
+	  https://github.com/ultravioletrs/cocos
@@ -0,0 +1,22 @@
+################################################################################
+#
+# Cocos AI Egress Proxy
+#
+################################################################################
+
+EGRESS_PROXY_VERSION = main
+EGRESS_PROXY_SITE = $(call github,ultravioletrs,cocos,$(EGRESS_PROXY_VERSION))
+
+define EGRESS_PROXY_BUILD_CMDS
+	$(MAKE) -C $(@D) egress-proxy
+endef
+
+define EGRESS_PROXY_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0755 $(@D)/build/cocos-egress-proxy $(TARGET_DIR)/usr/bin/egress-proxy
+endef
+
+define EGRESS_PROXY_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0644 $(@D)/init/systemd/egress-proxy.service $(TARGET_DIR)/usr/lib/systemd/system/egress-proxy.service
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,4 @@
+config BR2_PACKAGE_INGRESS_PROXY
+	bool "ingress-proxy"
+	help
+	  Cocos Ingress Proxy service.
@@ -0,0 +1,22 @@
+################################################################################
+#
+# ingress-proxy
+#
+################################################################################
+
+INGRESS_PROXY_VERSION = main
+INGRESS_PROXY_SITE = $(call github,ultravioletrs,cocos,$(INGRESS_PROXY_VERSION))
+
+define INGRESS_PROXY_BUILD_CMDS
+	$(MAKE) -C $(@D) ingress-proxy
+endef
+
+define INGRESS_PROXY_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0750 $(@D)/build/cocos-ingress-proxy $(TARGET_DIR)/usr/bin/ingress-proxy
+endef
+
+# NOTE: The ingress-proxy is managed per-computation by the agent, not as a standalone
+# systemd service. The binary is installed for use by the agent, but no systemd service
+# is created.
+
+$(eval $(generic-package))
@@ -0,0 +1,4 @@
+config BR2_PACKAGE_LOG_FORWARDER
+	bool "log-forwarder"
+	help
+	  Cocos AI Log Forwarder service.
@@ -0,0 +1,22 @@
+################################################################################
+#
+# log-forwarder
+#
+################################################################################
+
+LOG_FORWARDER_VERSION = main
+LOG_FORWARDER_SITE = $(call github,ultravioletrs,cocos,$(LOG_FORWARDER_VERSION))
+
+define LOG_FORWARDER_BUILD_CMDS
+	$(MAKE) -C $(@D) log-forwarder
+endef
+
+define LOG_FORWARDER_INSTALL_TARGET_CMDS
+	$(INSTALL) -D -m 0750 $(@D)/build/cocos-log-forwarder $(TARGET_DIR)/usr/bin/log-forwarder
+endef
+
+define LOG_FORWARDER_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 0640 $(@D)/init/systemd/log-forwarder.service $(TARGET_DIR)/usr/lib/systemd/system/log-forwarder.service
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,6 @@
+config BR2_PACKAGE_WASMEDGE
+    bool "wasmedge"
+	  default y
+    help
+      Wasmedge is a standalone runtime for WebAssembly.
+      https://wasmedge.org/docs/
@@ -0,0 +1,8 @@
+WASMEDGE_DOWNLOAD_URL = https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh
+
+define WASMEDGE_INSTALL_TARGET_CMDS
+    curl -sSf $(WASMEDGE_DOWNLOAD_URL) | bash -s -- -p $(TARGET_DIR)/usr -v 0.14.1
+    echo "source /usr/env" >> $(TARGET_DIR)/etc/profile
+endef
+
+$(eval $(generic-package))
@@ -0,0 +1,34 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+Subject: [PATCH] efi: skip lockdown when built with --disable-shim-lock
+
+When GRUB is built with --disable-shim-lock, grub_shim_lock_verifier_setup()
+returns early without registering the shim_lock verifier.  However
+grub_lockdown() was called unconditionally before that, registering the
+lockdown_verifier which marks kernel files as DEFER_AUTH.  With no verifier
+present to approve them, every kernel load fails with "verification requested
+but nobody cares".
+
+Fix by calling grub_shim_lock_verifier_setup() first and only calling
+grub_lockdown() if shim_lock is actually active.  This preserves full
+lockdown behaviour in shim-based chains while allowing direct
+OVMF->GRUB->kernel boot with a custom DB key and no shim.
+
+Signed-off-by: Cocos AI <build@cocos.ai>
+---
+ grub-core/kern/efi/init.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
+--- a/grub-core/kern/efi/init.c
+++ b/grub-core/kern/efi/init.c
+@@ -122,8 +122,9 @@
+    */
+   if (grub_efi_get_secureboot () == GRUB_EFI_SECUREBOOT_MODE_ENABLED)
+     {
+-      grub_lockdown ();
+       grub_shim_lock_verifier_setup ();
+      if (grub_is_shim_lock_enabled ())
+        grub_lockdown ();
+     }
+
+   grub_efi_system_table->boot_services->set_watchdog_timer (0, 0, 0, NULL);
@@ -10,7 +10,7 @@ HAL uses [Buildroot](https://buildroot.org/)'s [_External Tree_ mechanism](https
 git clone git@github.com:ultravioletrs/cocos.git
 git clone git@github.com:buildroot/buildroot.git
 cd buildroot
-git checkout 2025.08-rc3
+git checkout 2025.11
 make BR2_EXTERNAL=../cocos/hal/linux cocos_defconfig
 # Execute 'make menuconfig' only if you want to make additional configuration changes to Buildroot.
 make menuconfig
@@ -22,5 +22,8 @@ if [ ! -d "$WORK_DIR" ]; then
    mkdir -p $WORK_DIR
 fi

-# Resize the root file system to 100%
-mount -o remount,size=100% /
+# RAM-only agent images use tmpfs as the root filesystem
+ROOT_FSTYPE=$(awk '$2 == "/" { print $3; exit }' /proc/mounts)
+if [ "$ROOT_FSTYPE" = "tmpfs" ]; then
+    mount -o remount,size=100% /
+fi
@@ -1,7 +1,7 @@
 [Unit]
 Description=Cocos AI agent
-After=network.target attestation-service.service log-forwarder.service computation-runner.service egress-proxy.service coco-keyprovider.service
-Requires=log-forwarder.service computation-runner.service egress-proxy.service coco-keyprovider.service
+After=network.target attestation-service.service log-forwarder.service computation-runner.service egress-proxy.service
+Requires=log-forwarder.service computation-runner.service egress-proxy.service
 Before=docker.service

 [Service]
@@ -8,6 +8,7 @@ package attestation

 import (
 	context "context"
+
 	grpc "google.golang.org/grpc"
 	codes "google.golang.org/grpc/codes"
 	status "google.golang.org/grpc/status"
@@ -49,6 +49,12 @@ The service is configured using the environment variables from the following tab
 | MANAGER_QEMU_VIRTIO_NET_PCI_ROMFILE        | The file path for the ROM image for the virtio-net PCI device.                                                   |                                |
 | MANAGER_QEMU_DISK_IMG_KERNEL_FILE          | The file path for the kernel image.                                                                              | img/bzImage                    |
 | MANAGER_QEMU_DISK_IMG_ROOTFS_FILE          | The file path for the root filesystem image.                                                                     | img/rootfs.cpio.gz             |
+| MANAGER_QEMU_ENABLE_DISK                   | Whether to attach a writable qcow2 disk to the CVM.                                                              | false                          |
+| MANAGER_QEMU_SRC_DISK_FILE                 | Path to a qcow2 image whose virtual size is used to size the per-VM writable disk.                               | img/enc_os.qcow2               |
+| MANAGER_QEMU_DST_DISK_FILE                 | Runtime path of the per-VM writable disk created by the manager.                                                 |                                |
+| MANAGER_QEMU_DISK_ID                       | The QEMU drive identifier for the attached disk.                                                                 | disk0                          |
+| MANAGER_QEMU_DISK_FORMAT                   | The format of the attached disk image.                                                                           | qcow2                          |
+| MANAGER_QEMU_DISK_SCSI_ID                  | The SCSI controller identifier used for the attached disk.                                                       | scsi0                          |
 | MANAGER_QEMU_SEV_SNP_ID                    | The ID for the Secure Encrypted Virtualization (SEV-SNP) device.                                                 | sev0                           |
 | MANAGER_QEMU_SEV_SNP_CBITPOS               | The position of the C-bit in the physical address.                                                               | 51                             |
 | MANAGER_QEMU_SEV_SNP_REDUCED_PHYS_BITS     | The number of reduced physical address bits for SEV-SNP.                                                         | 1                              |
@@ -112,6 +118,20 @@ Once the image is built copy the kernel and rootfs image to `cmd/manager/img` fr

 Another option is to use release versions of EOS that can be downloaded from the [Cocos GitHub repository](https://github.com/ultravioletrs/cocos/releases).

+#### Optional writable disk
+
+If you want the manager to attach a writable disk to each CVM, place a qcow2 reference image at `cmd/manager/img/enc_os.qcow2`, or point `MANAGER_QEMU_SRC_DISK_FILE` to another qcow2 file.
+
+When `MANAGER_QEMU_ENABLE_DISK=true`, the manager:
+
+- reads the virtual size of `MANAGER_QEMU_SRC_DISK_FILE` with `qemu-img info`
+- creates a per-VM qcow2 disk under `/tmp/cvmDisk-<uuid>.qcow2`
+- sizes the disk to the source image size plus 1 GiB, leaving room for the LUKS header
+- attaches the disk through a virtio-scsi controller
+- removes the temporary disk again when the VM stops
+
+`MANAGER_QEMU_DST_DISK_FILE` is primarily a runtime value. In the normal manager flow it is populated automatically and usually does not need to be set manually.
+
 #### Test VM creation

 ```sh
@@ -207,7 +227,7 @@ nc -zv localhost 7020

 #### Conclusion

-Now you are able to use `Manager` with `Agent`. Namely, `Manager` will create a VM with a separate OVMF variables file on manager `/run` request.
+Now you are able to use `Manager` with `Agent`. On each manager `/run` request, the manager creates a VM with a separate OVMF variables file and, when enabled, a per-VM writable qcow2 disk.

 ### OVMF

@@ -284,6 +304,18 @@ MANAGER_QEMU_OVMF_FILE=<path to OVMF file> \
 ./build/cocos-manager
 ```

+To enable writable disk support, start manager like this
+
+```sh
+MANAGER_GRPC_URL=localhost:7001 \
+MANAGER_LOG_LEVEL=debug \
+MANAGER_QEMU_ENABLE_DISK=true \
+MANAGER_QEMU_SRC_DISK_FILE=<path to reference qcow2 image> \
+./build/cocos-manager
+```
+
+The reference qcow2 image is used to determine the disk size. The manager creates a fresh writable qcow2 disk for each VM under `/tmp` and deletes it on shutdown.
+
 ### Troubleshooting

 If the `ps aux | grep qemu-system-x86_64` give you something like this
@@ -294,16 +326,16 @@ darko      13913  0.0  0.0      0     0 pts/2    Z+   20:17   0:00 [qemu-system-

 means that the a QEMU virtual machine that is currently defunct, meaning that it is no longer running. More precisely, the defunct process in the output is also known as a ["zombie" process](https://en.wikipedia.org/wiki/Zombie_process).

-You can troubleshoot the VM launch procedure by running directly `qemu-system-x86_64` command. When you run `manager` with `MANAGER_LOG_LEVEL=info` env var set, it prints out the entire command used to launch a VM. The relevant part of the log might look like this
+You can troubleshoot the VM launch procedure by running directly `qemu-system-x86_64` command. When you run `manager` with `MANAGER_LOG_LEVEL=info` env var set, it prints out the entire command used to launch a VM. When writable disk support is enabled, the relevant part of the log might look like this

 ```
-{"level":"info","message":"/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=img/OVMF_VARS.fd -device virtio-scsi-pci,id=scsi,disable-legacy=on,iommu_platform=true -drive file=img/focal-server-cloudimg-amd64.img,if=none,id=disk0,format=qcow2 -device scsi-hd,drive=disk0 -netdev user,id=vmnic,hostfwd=tcp::2222-:22,hostfwd=tcp::9301-:9031,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,romfile= -nographic -monitor pty","ts":"2023-08-14T18:29:19.2653908Z"}
+{"level":"info","message":"/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=/tmp/OVMF_VARS-<uuid>.fd -netdev user,id=vmnic-<uuid>,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic-<uuid>,addr=0x2,romfile= -drive file=/tmp/cvmDisk-<uuid>.qcow2,if=none,id=disk0,format=qcow2 -device virtio-scsi-pci,id=scsi0,disable-legacy=on,iommu_platform=true -device scsi-hd,drive=disk0,bus=scsi0.0 -kernel img/bzImage -append quiet console=null -initrd img/rootfs.cpio.gz -nographic -monitor pty","ts":"2026-04-27T00:00:00Z"}
 ```

 You can run the command - the value of the `"message"` key - directly in the terminal:

 ```sh
-/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=img/OVMF_VARS.fd -device virtio-scsi-pci,id=scsi,disable-legacy=on,iommu_platform=true -drive file=img/focal-server-cloudimg-amd64.img,if=none,id=disk0,format=qcow2 -device scsi-hd,drive=disk0 -netdev user,id=vmnic,hostfwd=tcp::2222-:22,hostfwd=tcp::9301-:9031,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,romfile= -nographic -monitor pty
+/usr/bin/qemu-system-x86_64 -enable-kvm -machine q35 -cpu EPYC -smp 4,maxcpus=64 -m 4096M,slots=5,maxmem=30G -drive if=pflash,format=raw,unit=0,file=/usr/share/OVMF/OVMF_CODE.fd,readonly=on -drive if=pflash,format=raw,unit=1,file=/tmp/OVMF_VARS-<uuid>.fd -netdev user,id=vmnic-<uuid>,hostfwd=tcp::7020-:7002 -device virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic-<uuid>,addr=0x2,romfile= -drive file=/tmp/cvmDisk-<uuid>.qcow2,if=none,id=disk0,format=qcow2 -device virtio-scsi-pci,id=scsi0,disable-legacy=on,iommu_platform=true -device scsi-hd,drive=disk0,bus=scsi0.0 -kernel img/bzImage -append "quiet console=null" -initrd img/rootfs.cpio.gz -nographic -monitor pty
 ```

 and look for the possible problems. This problems can usually be solved by using the adequate env var assignments. Look in the `manager/qemu/config.go` file to see the recognized env vars. Don't forget to prepend `MANAGER_QEMU_` to the name of the env vars.
@@ -4,6 +4,7 @@ package qemu

 import (
 	"fmt"
+	"strings"

 	"github.com/caarlos0/env/v10"
 )
@@ -48,7 +49,7 @@ type VirtioNetPciConfig struct {
 	ROMFile       string `env:"VIRTIO_NET_PCI_ROMFILE"`
 }

-type DiskImgConfig struct {
+type KernelConfig struct {
 	KernelFile string `env:"DISK_IMG_KERNEL_FILE" envDefault:"img/bzImage"`
 	RootFsFile string `env:"DISK_IMG_ROOTFS_FILE" envDefault:"img/rootfs.cpio.gz"`
 }
@@ -72,9 +73,18 @@ type IGVMConfig struct {
 	File string `env:"IGVM_FILE"      envDefault:"/root/coconut-qemu.igvm"`
 }

+type DiskConfig struct {
+	SrcFile string `env:"SRC_DISK_FILE"   envDefault:"img/enc_os.qcow2"`
+	DstFile string `env:"DST_DISK_FILE"   envDefault:""`
+	ID      string `env:"DISK_ID"     envDefault:"disk0"`
+	Format  string `env:"DISK_FORMAT" envDefault:"qcow2"`
+	SCSIID  string `env:"DISK_SCSI_ID" envDefault:"scsi0"`
+}
+
 type Config struct {
 	EnableSEVSNP bool
 	EnableTDX    bool
+	EnableDisk   bool   `env:"ENABLE_DISK"    envDefault:"false"`
 	QemuBinPath  string `env:"BIN_PATH"       envDefault:"qemu-system-x86_64"`
 	UseSudo      bool   `env:"USE_SUDO"       envDefault:"false"`

@@ -96,8 +106,11 @@ type Config struct {
 	NetDevConfig
 	VirtioNetPciConfig

-	// disk
-	DiskImgConfig
+	// disk config
+	DiskConfig
+
+	// kernel and initramfs
+	KernelConfig

 	// SEV-SNP
 	SEVSNPConfig
@@ -123,6 +136,25 @@ type Config struct {
 	EnvMount   string `env:"ENV_MOUNT"   envDefault:""`
 }

+func (config Config) ValidateBootConfig() error {
+	if config.EnableDisk {
+		if strings.TrimSpace(config.DiskConfig.DstFile) == "" {
+			return fmt.Errorf("disk boot enabled but destination disk image is not set")
+		}
+		return nil
+	}
+
+	if strings.TrimSpace(config.KernelConfig.KernelFile) == "" {
+		return fmt.Errorf("kernel boot enabled but kernel image is not set")
+	}
+
+	if strings.TrimSpace(config.KernelConfig.RootFsFile) == "" {
+		return fmt.Errorf("kernel boot enabled but initramfs image is not set")
+	}
+
+	return nil
+}
+
 func (config Config) ConstructQemuArgs() []string {
 	args := []string{}

@@ -179,6 +211,22 @@ func (config Config) ConstructQemuArgs() []string {
 			config.VirtioNetPciConfig.Addr,
 			config.VirtioNetPciConfig.ROMFile))

+	if config.EnableDisk {
+		// disk image
+		args = append(args, "-drive",
+			fmt.Sprintf("file=%s,if=none,id=%s,format=%s",
+				config.DiskConfig.DstFile,
+				config.DiskConfig.ID,
+				config.DiskConfig.Format))
+		args = append(args, "-device",
+			fmt.Sprintf("virtio-scsi-pci,id=%s,disable-legacy=on,iommu_platform=true",
+				config.DiskConfig.SCSIID))
+		args = append(args, "-device",
+			fmt.Sprintf("scsi-hd,drive=%s,bus=%s.0",
+				config.DiskConfig.ID,
+				config.DiskConfig.SCSIID))
+	}
+
 	// SEV-SNP
 	if config.EnableSEVSNP {
 		sevSnpType := "sev-snp-guest"
@@ -233,9 +281,11 @@ func (config Config) ConstructQemuArgs() []string {
 		args = append(args, "-nodefaults")
 	}

-	args = append(args, "-kernel", config.DiskImgConfig.KernelFile)
-	args = append(args, "-append", config.KernelCommandLine)
-	args = append(args, "-initrd", config.DiskImgConfig.RootFsFile)
+	if !config.EnableDisk {
+		args = append(args, "-kernel", config.KernelConfig.KernelFile)
+		args = append(args, "-append", config.KernelCommandLine)
+		args = append(args, "-initrd", config.KernelConfig.RootFsFile)
+	}

 	// display
 	if config.NoGraphic {
@@ -51,7 +51,7 @@ func TestConstructQemuArgs(t *testing.T) {
 					IOMMUPlatform: true,
 					Addr:          "0x2",
 				},
-				DiskImgConfig: DiskImgConfig{
+				KernelConfig: KernelConfig{
 					KernelFile: "img/bzImage",
 					RootFsFile: "img/rootfs.cpio.gz",
 				},
@@ -115,7 +115,7 @@ func TestConstructQemuArgs(t *testing.T) {
 					IOMMUPlatform: true,
 					Addr:          "0x2",
 				},
-				DiskImgConfig: DiskImgConfig{
+				KernelConfig: KernelConfig{
 					KernelFile: "img/bzImage",
 					RootFsFile: "img/rootfs.cpio.gz",
 				},
@@ -194,3 +194,154 @@ func TestConstructQemuArgs_HostData(t *testing.T) {
 		t.Errorf("ConstructQemuArgs() did not contain expected SEV-SNP configuration with host data")
 	}
 }
+
+func TestConstructQemuArgs_TDX(t *testing.T) {
+	config := Config{
+		EnableKVM: true,
+		EnableTDX: true,
+		Machine:   "q35",
+		CPU:       "EPYC",
+		SMPCount:  4,
+		MaxCPUs:   64,
+		MemID:     "ram1",
+		MemoryConfig: MemoryConfig{
+			Size:  "4096M",
+			Slots: 8,
+			Max:   "64G",
+		},
+		NetDevConfig: NetDevConfig{
+			ID:            "vmnic",
+			HostFwdAgent:  7020,
+			GuestFwdAgent: 7002,
+		},
+		VirtioNetPciConfig: VirtioNetPciConfig{
+			DisableLegacy: "on",
+			IOMMUPlatform: true,
+			Addr:          "0x2",
+		},
+		TDXConfig: TDXConfig{
+			ID:                  "tdx0",
+			QuoteGenerationPort: 4050,
+			OVMF:                "/usr/share/ovmf/OVMF.fd",
+		},
+		KernelConfig: KernelConfig{
+			KernelFile: "img/bzImage",
+			RootFsFile: "img/rootfs.cpio.gz",
+		},
+		KernelCommandLine: "quiet console=null",
+		NoGraphic:         true,
+		Monitor:           "pty",
+	}
+
+	expected := []string{
+		"-enable-kvm",
+		"-machine", "q35",
+		"-cpu", "EPYC",
+		"-smp", "4,maxcpus=64",
+		"-m", "4096M,slots=8,maxmem=64G",
+		"-netdev", "user,id=vmnic,hostfwd=tcp::7020-:7002",
+		"-device", "virtio-net-pci,disable-legacy=on,iommu_platform=true,netdev=vmnic,addr=0x2,romfile=",
+		"-object", "{\"qom-type\":\"tdx-guest\",\"id\":\"tdx0\",\"quote-generation-socket\":{\"type\": \"vsock\", \"cid\":\"2\",\"port\":\"4050\"}}",
+		"-machine", "confidential-guest-support=tdx0,memory-backend=ram1,hpet=off",
+		"-object", "memory-backend-memfd,id=ram1,size=4096M,share=true,prealloc=false",
+		"-bios", "/usr/share/ovmf/OVMF.fd",
+		"-nodefaults",
+		"-kernel", "img/bzImage",
+		"-append", "quiet console=null",
+		"-initrd", "img/rootfs.cpio.gz",
+		"-nographic",
+		"-monitor", "pty",
+	}
+
+	result := config.ConstructQemuArgs()
+	if !reflect.DeepEqual(result, expected) {
+		t.Errorf("ConstructQemuArgs() = %v, want %v", result, expected)
+	}
+}
+
+func TestConstructQemuArgs_DiskBootSkipsKernelAndInitrd(t *testing.T) {
+	config := Config{
+		EnableKVM:  true,
+		EnableDisk: true,
+		Machine:    "q35",
+		CPU:        "EPYC",
+		SMPCount:   4,
+		MaxCPUs:    64,
+		MemID:      "ram1",
+		MemoryConfig: MemoryConfig{
+			Size:  "2048M",
+			Slots: 5,
+			Max:   "30G",
+		},
+		NetDevConfig: NetDevConfig{
+			ID:            "vmnic",
+			HostFwdAgent:  7020,
+			GuestFwdAgent: 7002,
+		},
+		VirtioNetPciConfig: VirtioNetPciConfig{
+			DisableLegacy: "on",
+			IOMMUPlatform: true,
+			Addr:          "0x2",
+		},
+		DiskConfig: DiskConfig{
+			DstFile: "img/disk.img",
+			ID:      "disk0",
+			Format:  "qcow2",
+			SCSIID:  "scsi0",
+		},
+		KernelConfig: KernelConfig{
+			KernelFile: "img/bzImage",
+			RootFsFile: "img/rootfs.cpio.gz",
+		},
+		NoGraphic: true,
+		Monitor:   "pty",
+	}
+
+	result := config.ConstructQemuArgs()
+
+	for _, forbidden := range []string{"-kernel", "-append", "-initrd"} {
+		for _, arg := range result {
+			if arg == forbidden {
+				t.Fatalf("ConstructQemuArgs() unexpectedly contained %s during disk boot: %v", forbidden, result)
+			}
+		}
+	}
+}
+
+func TestConstructQemuArgs_EnableDisk(t *testing.T) {
+	config := Config{
+		EnableDisk: true,
+		DiskConfig: DiskConfig{
+			SrcFile: "img/enc_os.qcow2",
+			DstFile: "img/enc_os_dst.qcow2",
+			ID:      "disk0",
+			Format:  "qcow2",
+			SCSIID:  "scsi0",
+		},
+	}
+
+	result := config.ConstructQemuArgs()
+
+	expected := []string{
+		"-drive", "file=img/enc_os_dst.qcow2,if=none,id=disk0,format=qcow2",
+		"-device", "virtio-scsi-pci,id=scsi0,disable-legacy=on,iommu_platform=true",
+		"-device", "scsi-hd,drive=disk0,bus=scsi0.0",
+	}
+
+	var found []bool = make([]bool, len(expected))
+	for i, arg := range result {
+		for j := 0; j < len(expected); j += 2 {
+			if arg == expected[j] && i+1 < len(result) && result[i+1] == expected[j+1] {
+				found[j] = true
+				found[j+1] = true
+				break
+			}
+		}
+	}
+
+	for j, f := range found {
+		if !f {
+			t.Errorf("ConstructQemuArgs() did not contain expected disk configuration: %s", expected[j])
+		}
+	}
+}
@@ -3,10 +3,12 @@
 package qemu

 import (
+	"encoding/json"
 	"fmt"
 	"log/slog"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"strings"
 	"syscall"
 	"time"
@@ -18,12 +20,15 @@ import (
 )

 const (
-	firmwareVars    = "OVMF_VARS"
-	KernelFile      = "bzImage"
-	rootfsFile      = "rootfs.cpio"
-	tmpDir          = "/tmp"
-	interval        = 5 * time.Second
-	shutdownTimeout = 30 * time.Second
+	firmwareVars                  = "OVMF_VARS"
+	KernelFile                    = "bzImage"
+	rootfsFile                    = "rootfs.cpio"
+	tmpDir                        = "/tmp"
+	diskDstName                   = "cvmDisk"
+	interval                      = 5 * time.Second
+	shutdownTimeout               = 30 * time.Second
+	encryptedPartitionSizeDeltaGB = 1
+	sourceDiskFormat              = "qcow2"
 )

 type VMInfo struct {
@@ -39,6 +44,10 @@ type qemuVM struct {
 	vm.StateMachine
 }

+type qemuInfo struct {
+	VirtualSize int64 `json:"virtual-size"`
+}
+
 func NewVM(config any, cvmId string, logger *slog.Logger) vm.VM {
 	return &qemuVM{
 		vmi:          config.(VMInfo),
@@ -75,6 +84,44 @@ func (v *qemuVM) Start() (err error) {
 		v.vmi.Config.OVMFVarsConfig.File = dstFile
 	}

+	if v.vmi.Config.EnableDisk {
+		srcDiskFile, err := filepath.Abs(v.vmi.Config.SrcFile)
+		if err != nil {
+			return err
+		}
+
+		sizeGB, err := GetVirtualSizeGB(srcDiskFile)
+		if err != nil {
+			return err
+		}
+
+		dstDiskFile := fmt.Sprintf("%s/%s-%s.%s", tmpDir, diskDstName, id, v.vmi.Config.DiskConfig.Format)
+		sizeArg := fmt.Sprintf("%dG", sizeGB+encryptedPartitionSizeDeltaGB)
+
+		cmd := exec.Command(
+			"qemu-img",
+			"convert",
+			"-f", sourceDiskFormat,
+			"-O", v.vmi.Config.DiskConfig.Format,
+			srcDiskFile,
+			dstDiskFile,
+		)
+		if out, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("qemu-img convert failed: %w: %s", err, string(out))
+		}
+
+		cmd = exec.Command(
+			"qemu-img",
+			"resize",
+			dstDiskFile,
+			sizeArg,
+		)
+		if out, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("qemu-img resize failed: %w: %s", err, string(out))
+		}
+		v.vmi.Config.DstFile = dstDiskFile
+	}
+
 	exe, args, err := v.executableAndArgs()
 	if err != nil {
 		return err
@@ -111,6 +158,14 @@ func (v *qemuVM) Stop() error {
 		}
 	}

+	if v.vmi.Config.EnableDisk {
+		if v.vmi.Config.DstFile != "" {
+			if err := os.RemoveAll(v.vmi.Config.DstFile); err != nil {
+				return fmt.Errorf("failed to remove disk file: %v", err)
+			}
+		}
+	}
+
 	done := make(chan error, 1)
 	go func() {
 		_, err := v.cmd.Process.Wait()
@@ -156,6 +211,10 @@ func (v *qemuVM) executableAndArgs() (string, []string, error) {
 		return "", nil, err
 	}

+	if err := v.vmi.Config.ValidateBootConfig(); err != nil {
+		return "", nil, err
+	}
+
 	args := v.vmi.Config.ConstructQemuArgs()

 	if v.vmi.Config.UseSudo {
@@ -231,3 +290,32 @@ func TDXEnabledOnHost() bool {

 	return TDXEnabled(string(cpuinfo), string(kernelParam))
 }
+
+func GetVirtualSizeBytes(path string) (int64, error) {
+	cmd := exec.Command("qemu-img", "info", "--output=json", path)
+	out, err := cmd.Output()
+	if err != nil {
+		return 0, fmt.Errorf("qemu-img info failed: %w", err)
+	}
+
+	var info qemuInfo
+	if err := json.Unmarshal(out, &info); err != nil {
+		return 0, fmt.Errorf("failed to parse qemu-img JSON: %w", err)
+	}
+
+	if info.VirtualSize <= 0 {
+		return 0, fmt.Errorf("invalid virtual size: %d", info.VirtualSize)
+	}
+
+	return info.VirtualSize, nil
+}
+
+func GetVirtualSizeGB(path string) (int, error) {
+	bytes, err := GetVirtualSizeBytes(path)
+	if err != nil {
+		return 0, err
+	}
+
+	gb := (bytes + (1<<30 - 1)) >> 30
+	return int(gb), nil
+}
@@ -3,9 +3,12 @@
 package qemu

 import (
+	"fmt"
 	"log/slog"
 	"os"
 	"os/exec"
+	"path/filepath"
+	"strings"
 	"testing"

 	"github.com/stretchr/testify/assert"
@@ -15,6 +18,31 @@ import (

 const testComputationID = "test-computation"

+func cleanupStrayQcow2(t *testing.T) {
+	t.Helper()
+
+	wd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("failed to get working directory: %v", err)
+	}
+
+	t.Cleanup(func() {
+		_ = os.Remove(filepath.Join(wd, "qcow2"))
+	})
+}
+
+func requireTempFile(t *testing.T, path string) {
+	t.Helper()
+
+	f, err := os.Create(path)
+	if err != nil {
+		t.Fatalf("failed to create temp file %s: %v", path, err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatalf("failed to close temp file %s: %v", path, err)
+	}
+}
+
 func TestNewVM(t *testing.T) {
 	config := VMInfo{Config: Config{}}

@@ -35,6 +63,10 @@ func TestStart(t *testing.T) {
 			File: tmpFile.Name(),
 		},
 		QemuBinPath: "echo",
+		KernelConfig: KernelConfig{
+			KernelFile: "img/bzImage",
+			RootFsFile: "img/rootfs.cpio.gz",
+		},
 	}}

 	vm := NewVM(config, testComputationID, slog.Default()).(*qemuVM)
@@ -58,6 +90,10 @@ func TestStartSudo(t *testing.T) {
 		},
 		QemuBinPath: "echo",
 		UseSudo:     true,
+		KernelConfig: KernelConfig{
+			KernelFile: "img/bzImage",
+			RootFsFile: "img/rootfs.cpio.gz",
+		},
 	}}

 	vm := NewVM(config, testComputationID, slog.Default()).(*qemuVM)
@@ -69,6 +105,136 @@ func TestStartSudo(t *testing.T) {
 	_ = vm.Stop()
 }

+func TestStart_EnableDisk(t *testing.T) {
+	cleanupStrayQcow2(t)
+
+	toolsDir := t.TempDir()
+	convertLogFile := filepath.Join(toolsDir, "qemu-img-convert.log")
+	resizeLogFile := filepath.Join(toolsDir, "qemu-img-resize.log")
+	srcDiskFile := filepath.Join(toolsDir, "enc_os.qcow2")
+	requireTempFile(t, srcDiskFile)
+
+	writeFakeExecutable(t, toolsDir, "qemu-img", fmt.Sprintf(`#!/bin/sh
+case "$1" in
+info)
+  printf '%%s' '{"virtual-size":2147483648}'
+  ;;
+convert)
+  printf '%%s\n' "$@" > %q
+  dst="$7"
+  : > "$dst"
+  ;;
+resize)
+  printf '%%s\n' "$@" > %q
+  ;;
+*)
+  echo "unexpected subcommand: $1" >&2
+  exit 2
+  ;;
+esac
+`, convertLogFile, resizeLogFile))
+
+	writeFakeExecutable(t, toolsDir, "fake-qemu", `#!/bin/sh
+trap 'exit 0' TERM INT
+while :; do
+  sleep 1
+done
+`)
+	prependPath(t, toolsDir)
+
+	config := VMInfo{Config: Config{
+		EnableTDX:   true,
+		EnableDisk:  true,
+		QemuBinPath: "fake-qemu",
+		DiskConfig: DiskConfig{
+			SrcFile: srcDiskFile,
+			ID:      "disk0",
+			Format:  "qcow2",
+			SCSIID:  "scsi0",
+		},
+	}}
+
+	vm := NewVM(config, testComputationID, slog.Default()).(*qemuVM)
+
+	err := vm.Start()
+	assert.NoError(t, err)
+	assert.NotNil(t, vm.cmd)
+	assert.Contains(t, vm.vmi.Config.DstFile, filepath.Join(tmpDir, diskDstName))
+	_, err = os.Stat(vm.vmi.Config.DstFile)
+	assert.NoError(t, err)
+
+	loggedArgs, err := os.ReadFile(convertLogFile)
+	assert.NoError(t, err)
+	assert.Equal(t, []string{
+		"convert",
+		"-f",
+		"qcow2",
+		"-O",
+		"qcow2",
+		srcDiskFile,
+		vm.vmi.Config.DstFile,
+	}, strings.Fields(string(loggedArgs)))
+
+	loggedArgs, err = os.ReadFile(resizeLogFile)
+	assert.NoError(t, err)
+	assert.Equal(t, []string{
+		"resize",
+		vm.vmi.Config.DstFile,
+		"3G",
+	}, strings.Fields(string(loggedArgs)))
+
+	err = vm.Stop()
+	assert.NoError(t, err)
+	_, err = os.Stat(vm.vmi.Config.DstFile)
+	assert.Error(t, err)
+	assert.True(t, os.IsNotExist(err))
+}
+
+func TestStart_EnableDiskCreateError(t *testing.T) {
+	cleanupStrayQcow2(t)
+
+	toolsDir := t.TempDir()
+	srcDiskFile := filepath.Join(toolsDir, "enc_os.qcow2")
+	requireTempFile(t, srcDiskFile)
+
+	writeFakeExecutable(t, toolsDir, "qemu-img", `#!/bin/sh
+case "$1" in
+info)
+  printf '%s' '{"virtual-size":2147483648}'
+  ;;
+convert)
+  echo 'disk create failed' >&2
+  exit 1
+  ;;
+resize)
+  exit 0
+  ;;
+*)
+  echo "unexpected subcommand: $1" >&2
+  exit 2
+  ;;
+esac
+`)
+	prependPath(t, toolsDir)
+
+	config := VMInfo{Config: Config{
+		EnableTDX:   true,
+		EnableDisk:  true,
+		QemuBinPath: "fake-qemu",
+		DiskConfig: DiskConfig{
+			SrcFile: srcDiskFile,
+		},
+	}}
+
+	vm := NewVM(config, testComputationID, slog.Default()).(*qemuVM)
+
+	err := vm.Start()
+	assert.Error(t, err)
+	assert.ErrorContains(t, err, "qemu-img convert failed")
+	assert.ErrorContains(t, err, "disk create failed")
+	assert.Nil(t, vm.cmd)
+}
+
 func TestStop(t *testing.T) {
 	t.Run("success", func(t *testing.T) {
 		cmd := exec.Command("echo", "test")
@@ -102,6 +268,42 @@ func TestStop(t *testing.T) {
 			StateMachine: sm,
 		}

+		err = vm.Stop()
+		assert.NoError(t, err)
+	})
+	t.Run("disk enable", func(t *testing.T) {
+		dir := t.TempDir()
+		dst := filepath.Join(dir, "disk.qcow2")
+
+		f, err := os.Create(dst)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := f.Close(); err != nil {
+			t.Fatal(err)
+		}
+
+		cmd := exec.Command("echo", "test")
+		err = cmd.Start()
+		assert.NoError(t, err)
+		sm := new(mocks.StateMachine)
+		sm.On("Transition", pkgmanager.StopComputationRun).Return(nil)
+
+		vm := &qemuVM{
+			vmi: VMInfo{
+				Config: Config{
+					EnableDisk: true,
+					DiskConfig: DiskConfig{
+						DstFile: dst,
+					},
+				},
+			},
+			cmd: &exec.Cmd{
+				Process: cmd.Process,
+			},
+			StateMachine: sm,
+		}
+
 		err = vm.Stop()
 		assert.NoError(t, err)
 	})
@@ -110,7 +312,13 @@ func TestStop(t *testing.T) {
 func TestSetProcess(t *testing.T) {
 	vm := &qemuVM{
 		vmi: VMInfo{
-			Config: Config{QemuBinPath: "echo"}, // Use 'echo' as a dummy QEMU binary
+			Config: Config{
+				QemuBinPath: "echo", // Use 'echo' as a dummy QEMU binary
+				KernelConfig: KernelConfig{
+					KernelFile: "img/bzImage",
+					RootFsFile: "img/rootfs.cpio.gz",
+				},
+			},
 		},
 	}

@@ -175,9 +383,156 @@ func TestTDXEnabled(t *testing.T) {
 }

 func TestSEVSNPEnabledOnHost(t *testing.T) {
-	assert.False(t, SEVSNPEnabledOnHost())
+	cpuinfo, cpuErr := os.ReadFile("/proc/cpuinfo")
+	kernelParam, kernelErr := os.ReadFile("/sys/module/kvm_amd/parameters/sev_snp")
+
+	expected := false
+	if cpuErr == nil && kernelErr == nil {
+		expected = SEVSNPEnabled(string(cpuinfo), string(kernelParam))
+	}
+
+	assert.Equal(t, expected, SEVSNPEnabledOnHost())
 }

 func TestTDXEnabledOnHost(t *testing.T) {
-	assert.False(t, TDXEnabledOnHost())
+	cpuinfo, cpuErr := os.ReadFile("/proc/cpuinfo")
+	kernelParam, kernelErr := os.ReadFile("/sys/module/kvm_intel/parameters/tdx")
+
+	expected := false
+	if cpuErr == nil && kernelErr == nil {
+		expected = TDXEnabled(string(cpuinfo), string(kernelParam))
+	}
+
+	assert.Equal(t, expected, TDXEnabledOnHost())
+}
+
+func TestGetVirtualSizeBytes_Success(t *testing.T) {
+	cleanup := writeFakeQemuImg(t, `{"virtual-size":2147483648}`, 0) // 2 GiB
+	defer cleanup()
+
+	got, err := GetVirtualSizeBytes("whatever.qcow2")
+	if err != nil {
+		t.Fatalf("expected nil error, got %v", err)
+	}
+	if got != 2147483648 {
+		t.Fatalf("expected 2147483648, got %d", got)
+	}
+}
+
+func TestGetVirtualSizeBytes_CommandFailure(t *testing.T) {
+	cleanup := writeFakeQemuImg(t, `{"virtual-size":2147483648}`, 1) // non-zero exit
+	defer cleanup()
+
+	_, err := GetVirtualSizeBytes("whatever.qcow2")
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "qemu-img info failed") {
+		t.Fatalf("expected wrapped error to contain %q, got %q", "qemu-img info failed", err.Error())
+	}
+}
+
+func TestGetVirtualSizeBytes_InvalidJSON(t *testing.T) {
+	cleanup := writeFakeQemuImg(t, `not-json`, 0)
+	defer cleanup()
+
+	_, err := GetVirtualSizeBytes("whatever.qcow2")
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "failed to parse qemu-img JSON") {
+		t.Fatalf("expected error to contain %q, got %q", "failed to parse qemu-img JSON", err.Error())
+	}
+}
+
+func TestGetVirtualSizeBytes_InvalidVirtualSize(t *testing.T) {
+	cleanup := writeFakeQemuImg(t, `{"virtual-size":0}`, 0)
+	defer cleanup()
+
+	_, err := GetVirtualSizeBytes("whatever.qcow2")
+	if err == nil {
+		t.Fatalf("expected error, got nil")
+	}
+	if !strings.Contains(err.Error(), "invalid virtual size") {
+		t.Fatalf("expected error to contain %q, got %q", "invalid virtual size", err.Error())
+	}
+}
+
+func TestGetVirtualSizeGB_RoundsUp(t *testing.T) {
+	tests := []struct {
+		name      string
+		virtualSz int64
+		wantGB    int
+	}{
+		{"exact_1GiB", 1 << 30, 1},
+		{"one_byte_over", (1 << 30) + 1, 2},
+		{"just_under_2GiB", (2 << 30) - 1, 2},
+		{"exact_2GiB", 2 << 30, 2},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			cleanup := writeFakeQemuImg(t, fmt.Sprintf(`{"virtual-size":%d}`, tc.virtualSz), 0)
+			defer cleanup()
+
+			got, err := GetVirtualSizeGB("whatever.qcow2")
+			if err != nil {
+				t.Fatalf("expected nil error, got %v", err)
+			}
+			if got != tc.wantGB {
+				t.Fatalf("expected %d, got %d", tc.wantGB, got)
+			}
+		})
+	}
+}
+
+func writeFakeQemuImg(t *testing.T, stdout string, exitCode int) func() {
+	dir := t.TempDir()
+	fake := filepath.Join(dir, "qemu-img")
+
+	script := fmt.Sprintf(`#!/bin/sh
+# Minimal fake for: qemu-img info --output=json <path>
+if [ "$1" != "info" ]; then
+  echo "unexpected subcommand: $1" >&2
+  exit 2
+fi
+
+# always print provided stdout, even if empty
+printf '%s' %q
+exit %d
+`, stdout, stdout, exitCode)
+
+	if err := os.WriteFile(fake, []byte(script), 0o755); err != nil {
+		t.Fatalf("failed to write fake qemu-img: %v", err)
+	}
+
+	oldPath := os.Getenv("PATH")
+	if err := os.Setenv("PATH", dir+string(os.PathListSeparator)+oldPath); err != nil {
+		t.Fatalf("failed to set PATH: %v", err)
+	}
+
+	return func() {
+		_ = os.Setenv("PATH", oldPath)
+	}
+}
+
+func writeFakeExecutable(t *testing.T, dir, name, script string) {
+	t.Helper()
+
+	path := filepath.Join(dir, name)
+	if err := os.WriteFile(path, []byte(script), 0o755); err != nil {
+		t.Fatalf("failed to write fake executable %q: %v", name, err)
+	}
+}
+
+func prependPath(t *testing.T, dir string) {
+	t.Helper()
+
+	oldPath := os.Getenv("PATH")
+	if err := os.Setenv("PATH", dir+string(os.PathListSeparator)+oldPath); err != nil {
+		t.Fatalf("failed to set PATH: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = os.Setenv("PATH", oldPath)
+	})
 }
				`@@ -0,0 +1 @@`
				`include $(sort $(wildcard $(BR2_EXTERNAL_COCOS_PATH)/package//.mk))`