Install
mkdir -p .claude/skills/asm-x86 && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/15848" && unzip -o skill.zip -d .claude/skills/asm-x86 && rm skill.zipInstalls to .claude/skills/asm-x86
Activation
This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.
x86 Assembly (Intel) — calling conventions, stack frames, registers, and low-level debugging procedure.Key capabilities
- →Read x86 assembly for performance or low-level debugging
- →Understand calling conventions, stack frames, and registers
- →Trace prologue and epilogue for control flow
- →Track values through registers and memory operands
- →Perform safety reviews for alignment and buffer overflows
How it works
This skill provides guidance for reading and debugging x86 assembly by establishing context, tracing control and data flow, and performing safety reviews. It uses standard calling conventions and debugging procedures.
Inputs & outputs
When to use asm-x86
- →Read assembly code
- →Debug assembly stack frame
- →Verify calling convention
About this skill
x86 Assembly (Intel) (Elite)
When to use
-
You need to read/write x86 assembly for performance or low-level debugging.
-
You need to understand calling conventions, stack frames, and registers.
Calling Convention Reference
| Convention | Platform | Args | Return | Caller-saved | Callee-saved |
|---|---|---|---|---|---|
cdecl | x86 Linux/Windows | Stack (right-to-left) | eax | eax,ecx,edx | ebx,esi,edi,ebp |
System V AMD64 | x64 Linux/macOS | rdi,rsi,rdx,rcx,r8,r9 | rax | r10,r11 | rbx,r12–r15,rbp |
Microsoft x64 | x64 Windows | rcx,rdx,r8,r9 | rax | rax,rcx,rdx,r8,r9,r10,r11 | rbx,rdi,rsi,r12–r15,rbp |
Workflow
1. Establish context
-
Architecture (x86/x64), OS, calling convention, toolchain.
-
Identify the function boundary (prologue/epilogue).
2. Read control flow
-
Trace prologue (stack frame setup) and epilogue (teardown).
-
Identify register saving/restoring patterns.
3. Trace data flow
-
Track values through registers and memory operands.
-
Note sign/zero extension issues (
movzx/movsx).
4. Debug effectively
-
Minimal repro, disassembly (
objdump -d,gdb,windbg). -
Set breakpoints at function entry; inspect registers and stack.
5. Safety review
-
Check alignment (stack 16-byte aligned before
callon x64). -
Look for buffer overflows, off-by-one stack usage.
-
Watch for UB and platform-specific behavior.
Self-check
-
Calling convention identified and respected.
-
Stack frame alignment verified (x64: 16-byte aligned before call).
-
Caller-saved vs callee-saved registers correctly handled.
-
Data flow traced for all inputs/outputs of the function.
-
Debugger used to confirm hypothesis before declaring fix.
Outputs
-
Calling convention and stack frame summary.
-
Debugging checklist (gdb/lldb/windbg commands).
-
"What to inspect" list (registers/stack/memory).
When not to use it
- →The task does not involve x86 assembly
- →The task is purely about high-level language debugging
- →The task is about database schema evolution without API surface impact
Limitations
- →The skill focuses on x86 assembly (Intel)
- →The skill provides reference for specific calling conventions like `cdecl` and `System V AMD64`
- →The skill provides reference for specific calling conventions like `Microsoft x64`
How it compares
This workflow offers a structured methodology for assembly-level analysis and debugging, providing specific steps and checks that go beyond generic debugging techniques for higher-level languages.
Compared to similar skills
asm-x86 side by side with the closest alternatives in the catalog.
| Skill | Installs | Updated | Safety | Difficulty |
|---|---|---|---|---|
| asm-x86 (this skill) | 0 | 2mo | No flags | Advanced |
| unreal-engine-cpp-pro | 43 | 4mo | No flags | Advanced |
| llvm-tooling | 1 | 6mo | Review | Advanced |
| static-analysis | 5 | 6mo | No flags | Advanced |
Try saying
Example prompts that trigger this skill in your AI assistant.
More by nist0
View all by nist0 →You might also like
unreal-engine-cpp-pro
sickn33
Expert guide for Unreal Engine 5.x C++ development, covering UObject hygiene, performance patterns, and best practices.
llvm-tooling
gmh5225
Expertise in LLVM tooling development including Clang plugins, LLDB debugger extensions, Clangd/LSP, and LibTooling. Use this skill when building source code analysis tools, refactoring tools, debugger extensions, or IDE integrations.
static-analysis
gmh5225
Expertise in LLVM-based static analysis including dataflow analysis, pointer analysis, taint tracking, and program verification. Use this skill when implementing security scanners, bug finders, code quality tools, or performing program analysis research.
memory-safety-patterns
sickn33
Implement memory-safe programming with RAII, ownership, smart pointers, and resource management across Rust, C++, and C. Use when writing safe systems code, managing resources, or preventing memory bugs.
debug-lldb
regenrek
Capture and analyze thread backtraces with LLDB/GDB to debug hangs, deadlocks, UI freezes, IPC stalls, or high-CPU loops across any language or project. Use when an app becomes unresponsive, switching contexts stalls, or you need thread stacks to locate lock inversion or blocking calls.
rsyslog-test
rsyslog
Standardizes testing and validation for rsyslog using the diag.sh framework.