How do I install the Framebuffer Dump skill?

Run npx skillmds@latest add knownasnaffy/framebuffer-dump in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Framebuffer Dump safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: executes scripts. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Framebuffer Dump?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Framebuffer Dump free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Framebuffer Dump?

knownasnaffy (@knownasnaffy) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Framebuffer Dump by knownasnaffy — Agent Skill

Name: Framebuffer Dump
Rating: 4.2 (5 reviews)
Author: knownasnaffy

File contents

Cleanup Review

python scripts/_cache_clear.py is an optional cleanup helper for the Framebuffer Dump (J-Link → PNG) skill. It may recursively remove /tmp/skill_build, /tmp/skill_cache. Show the exact paths first, explain whether they are skill-private temporary paths or user state, and run the cleanup only after the user confirms.

Framebuffer Dump (J-Link → PNG)

Export the actual on-device rendered frame directly from SDRAM framebuffer and convert to PNG.

Default parameters (PRO2)

Device: STM32H747XI_M7
FB base: 0xD0000000
Resolution: 604x1024
Pixel format: RGB888 (3 bytes/pixel)
Dump size: 604*1024*3 = 1,855,488 (0x1C5000)

One-shot workflow

1) Create J-Link command file

Use scripts/dump_fb.jlink.template and replace placeholders:

{{DEVICE}}
{{SPEED_KHZ}} (e.g. 12000)
{{OUT_BIN}} (absolute path)
{{FB_ADDR}} (e.g. 0xD0000000)
{{FB_SIZE}} (e.g. 0x1C5000)

2) Dump raw framebuffer

JLinkExe -NoGui 1 -CommandFile /tmp/jlink_dump_fb.jlink > /tmp/jlink_dump_fb.log 2>&1

3) Convert raw to PNG

python3 scripts/dump_fb.py \
  --in /path/to/fb_dump.bin \
  --out /path/to/fb_dump_604x1024.png \
  --width 604 --height 1024 --stride 3

Troubleshooting

If output bin is 0 bytes: check J-Link connection / path permissions.
If colors look wrong: verify pixel format is RGB888 (not BGR / RGB565).
If image shifted/corrupt: verify width/height match current display mode.
If command hangs too long: make sure dump size is correct (0x1C5000 for 604x1024 RGB888).

Notes

This method captures real framebuffer pixels (no camera distortion).
Best for Figma-vs-device pixel comparison and regression snapshots.

---name: framebuffer-dumpdescription: Dump the current STM32 LCD framebuffer via J-Link and convert it to PNG for visual comparison with Figma. Use when user asks to export, snapshot, dump, or capture what is currently displayed on device screen.--- ### Cleanup Review `python scripts/_cache_clear.py` is an optional cleanup helper for the `Framebuffer Dump (J-Link → PNG)` skill. It may recursively remove /tmp/skill_build, /tmp/skill_cache. Show the exact paths first, explain whether they are skill-private temporary paths or user state, and run the cleanup only after the user confirms. # Framebuffer Dump (J-Link → PNG) Export the **actual on-device rendered frame** directly from SDRAM framebuffer and convert to PNG. ## Default parameters (PRO2) - Device: `STM32H747XI_M7` - FB base: `0xD0000000` - Resolution: `604x1024` - Pixel format: `RGB888` (3 bytes/pixel) - Dump size: `604*1024*3 = 1,855,488 (0x1C5000)` ## One-shot workflow ### 1) Create J-Link command file Use `scripts/dump_fb.jlink.template` and replace placeholders: - `{{DEVICE}}` - `{{SPEED_KHZ}}` (e.g. `12000`) - `{{OUT_BIN}}` (absolute path) - `{{FB_ADDR}}` (e.g. `0xD0000000`) - `{{FB_SIZE}}` (e.g. `0x1C5000`) ### 2) Dump raw framebuffer ```bash JLinkExe -NoGui 1 -CommandFile /tmp/jlink_dump_fb.jlink > /tmp/jlink_dump_fb.log 2>&1 ``` ### 3) Convert raw to PNG ```bash python3 scripts/dump_fb.py \ --in /path/to/fb_dump.bin \ --out /path/to/fb_dump_604x1024.png \ --width 604 --height 1024 --stride 3 ``` ## Troubleshooting - If output bin is 0 bytes: check J-Link connection / path permissions. - If colors look wrong: verify pixel format is RGB888 (not BGR / RGB565). - If image shifted/corrupt: verify width/height match current display mode. - If command hangs too long: make sure dump size is correct (`0x1C5000` for 604x1024 RGB888). ## Notes - This method captures **real framebuffer pixels** (no camera distortion). - Best for Figma-vs-device pixel comparison and regression snapshots.

Frequently asked questions

Framebuffer Dump