Agent skill

Bootloaders Embedded

by mohitmishra786 in mohitmishra786/low-level-dev-skills

Embedded bootloader skill for firmware update and app handoff.

MITAuto-check passedDevelopment

Install Bootloaders Embedded

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .claude/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .claude/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .agents/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .agents/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .cursor/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .cursor/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/mohitmishra786/low-level-dev-skills.git --path skills/baremetal/bootloaders-embedded

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .gemini/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .gemini/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .github/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .github/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills bootloaders-embedded --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/baremetal/bootloaders-embedded .opencode/skills/bootloaders-embedded && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "bootloaders-embedded" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/baremetal/bootloaders-embedded into .opencode/skills/bootloaders-embedded/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "bootloaders-embedded", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: bootloaders-embedded
GitHub stars: 253
Token cost: ~1.1k tokens
SKILL.md length: 296 words
Files: 1
Skills in repo: 138
Repo updated: Jun 27, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Embedded bootloader skill for firmware update and app handoff.

Works in 7 steps: Memory layout (typical STM32) → Valid application image check → Cortex-M handoff sequence → …
Writing a custom bootloader
SKILL.md covers Purpose, When to Use, Workflow and Common Problems, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Bootloaders Embedded is an agent skill from mohitmishra786/low-level-dev-skills. Embedded bootloader skill for firmware update and app handoff. Use when writing a custom bootloader, jumping to application code, relocating VTOR, or implementing DFU/USB firmware update on Cortex-M. Activates on queries about bootloader jump, vector table relocation, application entry point, STM32 DFU, or dual-bank flash.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Development. The repository describes itself as: A curated suite of AI agent skills for systems and low-level programming with C/C++, Rust, and Zig toolchains, covering compilers, debuggers, profilers, build systems…. The licence is MIT.

When your agent uses it

Writing a custom bootloader
Jumping to application code
Relocating VTOR
Implementing DFU/USB firmware update on Cortex-M

Example prompts

“/bootloaders-embedded”

Workflow steps

7 steps, taken from the step headings in SKILL.md.

Memory layout (typical STM32)
Valid application image check
Cortex-M handoff sequence
Bootloader responsibilities
STM32 system memory DFU (factory ROM)
Update safety
Agent usage

What it can do on your machine

Read from SKILL.md and the folder at commit bdc5847. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are c).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Bootloaders Embedded loads about 1.1k tokens when it runs. Until then it costs about 86 tokens; SKILL.md has 296 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~86
When it runs · the whole SKILL.md, loaded when a task matches: ~1.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from mohitmishra786/low-level-dev-skills at commit bdc5847, republished under its MIT licence (© mohitmishra786). 296 words, ~1,063 tokens.

Download SKILL.mdSave it as .claude/skills/bootloaders-embedded/SKILL.md (or your agent's skills folder).

name: bootloaders-embedded
description: Embedded bootloader skill for firmware update and app handoff. Use when writing a custom bootloader, jumping to application code, relocating VTOR, or implementing DFU/USB firmware update on Cortex-M. Activates on queries about bootloader jump, vector table relocation, application entry point, STM32 DFU, or dual-bank flash.

Embedded Bootloaders

Purpose

Guide agents through embedded bootloader fundamentals: vector table relocation, safe handoff from bootloader to application, flash partitioning, and basic firmware-update patterns (UART, USB DFU, or custom protocol) on Cortex-M and similar MCUs.

When to Use

Application must run at non-zero flash offset (e.g. 0x08010000)
Implementing OTA or USB DFU without vendor HAL
Debugging "app works when flashed alone but not via bootloader"
Integrating with skills/baremetal/baremetal-startup and skills/baremetal/stm32-baremetal

Workflow

1. Memory layout (typical STM32)

Region	Address	Size	Content
Bootloader	`0x08000000`	16–64 KB	BL code, update logic
Application	`0x08010000`	remainder	App vector + code

Linker script for app must set FLASH ORIGIN to app base; vector table must live at app base.

2. Valid application image check

Before jump, verify:

App vector[0] (initial SP) points into RAM region
App vector[1] (Reset) points into flash region and has Thumb bit set (LSB=1)
Optional: CRC or magic word in app metadata section

#define APP_BASE  0x08010000U

static int app_valid(uint32_t base)
{
    uint32_t sp = *(uint32_t *)base;
    uint32_t reset = *(uint32_t *)(base + 4);
    if (sp < SRAM_BASE || sp > SRAM_END)
        return 0;
    if ((reset & 1U) == 0U)
        return 0;
    if (reset < base || reset > FLASH_END)
        return 0;
    return 1;
}

3. Cortex-M handoff sequence

typedef void (*app_entry_t)(void);

void jump_to_app(uint32_t app_base)
{
    uint32_t sp    = *(uint32_t *)app_base;
    uint32_t reset = *(uint32_t *)(app_base + 4);

    /* Disable interrupts and de-init peripherals/boot-owned hardware */
    __disable_irq();
    SysTick->CTRL = 0;
    for (int i = 0; i < 8; i++) {
        NVIC->ICER[i] = 0xFFFFFFFFU;
        NVIC->ICPR[i] = 0xFFFFFFFFU;
    }

    SCB->VTOR = app_base;
    __set_MSP(sp);
    __DSB();
    __ISB();

    app_entry_t entry = (app_entry_t)reset;
    entry(); /* does not return */
}

Application must set SCB->VTOR = APP_BASE early in Reset_Handler if startup assumes relocatable vector table.

4. Bootloader responsibilities

Power-on
├── Init minimal clock + UART/USB for update
├── Check update flag in RTC backup / GPIO strap
├── If update requested → receive image, verify, program flash
└── Else if valid app → jump_to_app()
    └── Else stay in bootloader shell

5. STM32 system memory DFU (factory ROM)

STM32 chips expose USB DFU in system memory when BOOT0=1. Custom bootloaders are separate — do not confuse ROM DFU with user flash BL.

6. Update safety

Write to scratch sector, verify CRC, then swap metadata pointer (A/B)
Never erase the only valid image without recovery path
Reset watchdog only after verified commit

7. Agent usage

/bootloaders-embedded Write STM32F4 jump-to-app at 0x08010000 with VTOR setup

Common Problems

Symptom	Cause	Fix
HardFault after jump	SP invalid or Thumb bit missing	Validate vectors; ensure `reset \| 1`
IRQs hit bootloader handlers	VTOR not relocated	Set `SCB->VTOR` before enabling IRQs
App OK standalone, fails via BL	Linker still at `0x08000000`	Relink app with correct ORIGIN
UART garbage after jump	BL left UART running	De-init or reset peripherals
Brick after OTA	Power loss mid-erase	Dual-bank or metadata rollback

skills/baremetal/baremetal-startup — vector table and Reset_Handler
skills/baremetal/stm32-baremetal — flash map and CMSIS
skills/baremetal/interrupts-and-exceptions-baremetal — NVIC disable pattern
skills/embedded/linker-scripts — VMA/LMA for split images
skills/embedded/openocd-jtag — recover bricked flash

Files

Just SKILL.md in skills/baremetal/bootloaders-embedded of mohitmishra786/low-level-dev-skills.

Open the folder on GitHubat commit bdc5847

Compare with similar skills

Bootloaders Embedded next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Bootloaders Embedded compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Bootloaders Embedded this skillmohitmishra786/low-level-dev-skills	253	—	~1.1k	Automated safety check: Pass	MIT	3 mo ago
Vercel Composition Patternssupabase/supabase	111k	58 repos	~726	Automated safety check: Pass	MIT	today
Finishing a Development Branchobra/superpowers	297k	5 repos	~1.9k	Automated safety check: Pass	MIT	today
Typescript Advanced Typesrolling-scopes/rsschool-app	10k	25 repos	~4.2k	Automated safety check: Pass	MPL-2.0	4 days ago
PR Babysitteropeninterpreter/openinterpreter	69k	3 repos	~4.2k	Automated safety check: Pass	Apache-2.0	2 days ago
Code Review ChecklistshareAI-lab/learn-claude-code	78k	5 repos	~1.1k	Automated safety check: Pass	MIT	10 days ago

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Questions about Bootloaders Embedded

What does Bootloaders Embedded do?

Embedded bootloader skill for firmware update and app handoff. Bootloaders Embedded is an agent skill from mohitmishra786/low-level-dev-skills. Embedded bootloader skill for firmware update and app handoff.

When should I use Bootloaders Embedded?

Bootloaders Embedded fits situations like: writing a custom bootloader; jumping to application code; relocating VTOR; implementing DFU/USB firmware update on Cortex-M.

How do I install Bootloaders Embedded in Claude Code?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a claude-code`. Or copy the skill folder (skills/baremetal/bootloaders-embedded in mohitmishra786/low-level-dev-skills) into .claude/skills/bootloaders-embedded in your project. Claude Code loads it when a task matches its description.

How do I install Bootloaders Embedded in Codex?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a codex`. Or copy the skill folder (skills/baremetal/bootloaders-embedded in mohitmishra786/low-level-dev-skills) into .agents/skills/bootloaders-embedded in your project. Codex loads it when a task matches its description.

Can I use Bootloaders Embedded in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mohitmishra786/low-level-dev-skills --skill bootloaders-embedded -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/bootloaders-embedded, .gemini/skills/bootloaders-embedded, .github/skills/bootloaders-embedded and .opencode/skills/bootloaders-embedded in your project.

What does Bootloaders Embedded need to run?

SKILL.md names no scripts, command-line tools or credentials: Bootloaders Embedded is instructions for the agent only.

Does Bootloaders Embedded access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Bootloaders Embedded safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Bootloaders Embedded use?

Bootloaders Embedded is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Bootloaders Embedded use?

About 1.1k tokens (SKILL.md is roughly 4.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Bootloaders Embedded?

Skills that share tags, products or a category with Bootloaders Embedded: Vercel Composition Patterns (supabase/supabase, 111k stars), Finishing a Development Branch (obra/superpowers, 297k stars), Typescript Advanced Types (rolling-scopes/rsschool-app, 10k stars) and PR Babysitter (openinterpreter/openinterpreter, 69k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Bootloaders Embedded?

mohitmishra786 (a GitHub user) maintains it in mohitmishra786/low-level-dev-skills, which has 253 GitHub stars. The repository holds 138 skills in this directory. The repository was last updated on June 27, 2026.

Source: mohitmishra786/low-level-dev-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Bootloaders Embedded

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Embedded Bootloaders

Purpose

When to Use

Workflow

1. Memory layout (typical STM32)

2. Valid application image check

3. Cortex-M handoff sequence

4. Bootloader responsibilities

5. STM32 system memory DFU (factory ROM)

6. Update safety

7. Agent usage

Common Problems

Related Skills

Files

Compare with similar skills

Similar skills

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Related

Questions about Bootloaders Embedded