Qemu Image Layout

QEMU Image Layout

Use this primitive before packaging or booting any disk, SD, eMMC, flash, pflash, firmware, or multi-partition image.

Composition

1. Start from qemu-flow-plan.
2. Use qemu-source-provenance for every input artifact.
3. Write the image contract to build/agent//image-layout.md.
4. Feed verified image paths into qemu-boot-run.

Layout Record

Use this structure:

# Image Layout

## Image Summary

| Image | Format | Virtual size | Actual size | SHA256 | Mutable? |
| --- | --- | --- | --- | --- | --- |

## Partition or Region Map

| Region | Start | Size | Type | Filesystem | Purpose | Source |
| --- | --- | --- | --- | --- | --- | --- |

## Write Operations

| Order | Input | Output image | Offset/seek | Block size | Size | Command | Verified by |
| --- | --- | --- | --- | --- | --- | --- | --- |

## Boot-Relevant Files

## Mutation Policy

## Verification Notes

Rules

• Work on a scratch copy unless the user explicitly wants to mutate the original image.
• Record byte offsets or sector offsets unambiguously. Include block size when using dd.
• Record partition start sectors before deriving absolute offsets.
• Hash the image before and after packaging when repeatability matters.
• Treat firmware, bootloader, kernel, DTB, rootfs, and modules as separate inputs even when packed into one image.
• If a boot failure appears after repeated runs, check whether the image was mutated before changing QEMU model code.

Useful Checks

qemu-img info 
fdisk -l 
sfdisk -d 
file 
sha256sum 

Use platform-specific tools only when the local image format requires them, and record the exact command.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: processmission
• Source: processmission/oh-my-qemu
• License: MIT
• Homepage: https://processmission.github.io/oh-my-qemu/

Install and usage instructions live in the source repository linked above.