jasm

jasm is a pure Jerboa binary-to-assembly source library and CLI.

The goal is to grow toward llvm-objdump-style decoding and output parity without linking to LLVM, shelling out to LLVM tools, using FFI, or requiring external libraries at runtime.

Current Scope

• Pure Jerboa decoder core.
• Seed x86-64 decoder for common prologue/control-flow instructions.
• Seed AArch64 decoder for common integer/load/store/return instructions.
• A Jerboa CLI for raw byte disassembly.

Object-file readers and broader ISA tables live in Jerboa .ss source modules.

Security and Release Gates

make verify
make release-evidence

make verify runs the local security baseline, import check, normal tests, malformed parser regression tests, deterministic object-fuzz evidence, and native binary smoke tests. Release evidence is written to dist/release-evidence/ with SBOM, reproducibility, and target proof status.

Runtime file reads are bounded by JASM_MAX_INPUT_BYTES (default 64 MiB). Raw hex CLI input is bounded by JASM_MAX_HEX_CHARS (default 16 MiB).

Generated native artifacts are ignored and must not be tracked. The root jasm binary is built by make binary and is a release artifact, not source.

Production support also requires a reviewed JASM_TARGET_PROOF_FILE with the markers documented in docs/release-evidence.md. JASM_REQUIRE_TARGET_PROOF=1 fails closed when that target proof is missing or incomplete.

Run

make verify
make binary
./jasm raw --arch x86-64 --syntax intel --hex '55 48 89 e5 c3'
./jasm raw --arch aarch64 --hex '20 00 80 d2 c0 03 5f d6'
./jasm raw --arch mips --hex '27 bd ff e0 03 e0 00 08'

Security Docs

• SECURITY.md
• docs/threat-model.md
• docs/parser-hardening.md
• docs/release-evidence.md

Source API

(import (jerboa prelude))

(include "lib/jasm/instruction.ss")
(include "lib/jasm/format.ss")
(include "lib/jasm/disasm.ss")

(disassemble->string 'x86-64 (hex-string->bytevector "55 48 89 e5")
  '((syntax . intel) (address . 0)))