assembly-arm

assembly-arm is a skill for Codex from OutlineDriven/outline-driven-development. It costs 55 tokens per session (1,753 once invoked), scanned A, original, Apache-2.0.

A guide to reading and writing ARM and AArch64 assembly, the low-level instructions used by ARM processors. It covers C inline assembly, function-call register rules, and vector code using NEON or SVE.

In plain words
What is it for?
Use it to inspect compiler output, write ARM assembly or inline assembly, follow AArch64 calling conventions, and work with NEON or SVE vectors.
Why use it?
It helps explain compiler-generated ARM code and avoid mistakes when hand-writing instructions or embedding them in C.

Skill for Codex

Written for Codex: agents/openai.yaml present.

Good fit Use it to inspect compiler output, write ARM assembly or inline assembly, follow AArch64 calling conventions, and work with NEON or SVE vectors.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/outlinedriven/outline-driven-development/assembly-arm
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add OutlineDriven/outline-driven-development --skill assembly-arm
Clone the repo
git clone --depth 1 https://github.com/OutlineDriven/outline-driven-development

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for assembly-arm

README.md
[![agentmods](https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/assembly-arm/github.svg)](https://agentmods.dev/skills/outlinedriven/outline-driven-development/assembly-arm)
Your own site
<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/assembly-arm"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/assembly-arm/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for assembly-arm

Your own site · 80×15
<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/assembly-arm"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/assembly-arm.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,753 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.01753
Opus 5 $0.00028 $0.00877
Sonnet 5 $0.00011 $0.00351
Haiku 4.5 $0.00006 $0.00175

Measured 3d ago against content hash 994fcd912e88, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

assembly-arm scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.devin/skills/assembly-arm/SKILL.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ARM and AArch64 assembly

AArch64 has 31 general 64-bit registers, a clean load-store instruction set, and per-core SIMD through NEON. This skill reads compiler output and writes correct inline asm for it.

Contract

Field Bound contract
Trigger The task reads GCC or Clang AArch64 output, writes inline asm or standalone assembly, decodes AAPCS64 register roles, or writes NEON intrinsics or SVE kernels.
Authority Read-only. The skill explains, drafts, and annotates assembly; edits land in the user's source through the normal coding path. No remote mutation.
Side effect None. Output is analysis and drafted code in chat.
Done The drafted assembly assembles for the named target, or the compiler output under discussion is explained register by register.

Inputs

  • The C or C++ source, compiler output, or assembly fragment: required.
  • The target: required. aarch64-linux-gnu for application cores, arm-none-eabi with -mthumb for 32-bit Cortex-M.
  • The purpose: required. Reading output, writing inline asm, or vectorizing.

Procedure

  1. Generate a baseline. Write the C version first and read its output before hand-writing anything. Done when: the compiler's own code for the same function is on screen.
aarch64-linux-gnu-gcc -O2 -S foo.c -o foo.s
aarch64-linux-gnu-objdump -d a.out
  1. Map registers by role. The table names are the ABI's, and assembly must respect them. Done when: every register in the fragment is classified.
Register Alias Role
x0 to x7 w0 for 32-bit use Arguments and return values, caller saved
x8 Indirect result location, or syscall number on Linux
x9 to x15 Temporaries, caller saved
x16, x17 ip0, ip1 Intra-procedure call scratch, do not keep values across calls
x18 Platform register, reserved on some platforms, do not use
x19 to x28 Callee saved
x29 fp Frame pointer
x30 lr Link register, return address
sp Stack pointer, must stay 16-byte aligned at public interfaces
v0 to v7 q/d/s views FP and SIMD arguments and returns, caller saved
v8 to v15 Callee saved, low 64 bits only

Read the full file on GitHub · 124 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 124 lines · 55 tokens per session scan A 994fcd912e88

Subscribe to this mod's changes

assembly-arm is a skill published in the GitHub repository OutlineDriven/outline-driven-development (52 stars, last pushed 4d ago), licensed Apache-2.0. It adds 55 tokens to every session and 1,753 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-06.

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