✨
Disclosure:this tutorial was drafted with AI assistance. Every technical claim is verified and source-traced in the linked repository.
AI assistants are confident about assembly — and wrong in specific, repeatable ways. They invent mnemonics that do not exist, flip AT&T/Intel operand order, silently drop immediates, and misread bytes. When we audited real incidents, the failures shared a signature: the code looks plausible and never errors.
The fix isn't "be more careful". It's a mechanical gate you can run in seconds.
gcc -c sample.s && objdump -d sample.o
gcc -c -masm=intel sample.s && objdump -d -M intel sample.o
If the disassembly does not match what you wrote — same mnemonic, same operands, same size — you did not write that instruction. Three real cases this catches:
movqad
is not an instruction. The assembler rejects it — so far, so good. The dangerous ones compile.
imul eax, eax, 38 ; assembles to: 69 c0 00 00 00 00
The 38
is silently dropped by the parser — this is the bug class behind BBoeOS PR#584. The code compiles. The intent is gone.
-masm=intel
flips the operand order (mov eax, [rax]
vs mov (%rax), %eax
). Mixing AT&T and Intel in one file silently changes semantics.
Compiling proves your syntax fits some grammar. It does not prove the encoding matches your intent. LLM-based disassembly gets exact instruction matches right about 14% of the time; "corrected" decompilations are right about 37%. The confidence-to-correctness gap is exactly where the expensive bugs live.
Verify real parallelism (thread counts + wall time, not thread-safe syntax). Verify the API actually exists (cargo search
, not memory). Verify your verification — a harness that can't fail is not evidence.
The full failure catalog and the skills that encode these gates live in
** https://github.com/TrothByte/low-level-skills-trothbyte** —
researched
with exact verification commands.
git clone https://github.com/TrothByte/low-level-skills-trothbyte
python tools/validate.py # 124 skills + registry + 177 sources, gated in seconds
Also installable via npx skills add TrothByte/low-level-skills-trothbyte
or as a Claude Code plugin marketplace.
Found a failure we haven't catalogued? The repo accepts issues — every new skill must be source-traced and differentiated from the existing 124. Watch the repository to get updates as it grows.