dump_spcr

dump_spcr.sh

#!/usr/bin/env bash
# dump_spcr.sh: Dump and decompile the ACPI SPCR table

set -euo pipefail

usage() {
  cat <<EOF
Usage: $(basename "$0") -o OUTPUT_PREFIX

Options:
  -o OUTPUT_PREFIX  Prefix for output files (e.g., /tmp/spcr)
      Generates two files:
        OUTPUT_PREFIX.dat   (binary SPCR table)
        OUTPUT_PREFIX.dsl   (ASL disassembly)
EOF
  exit 1
}

# Parse options
while getopts ":o:" opt; do
  case "$opt" in
    o) output_prefix="$OPTARG" ;;
    *) usage ;;
  esac
done

# Check that -o was provided
if [[ -z ${output_prefix:-} ]]; then
  usage
fi

# Path to SPCR table
table_path="/sys/firmware/acpi/tables/SPCR"
if [[ ! -r "$table_path" ]]; then
  echo "Error: SPCR table not found at $table_path" >&2
  exit 2
fi

# Dump binary table
echo "Dumping binary SPCR to ${output_prefix}.dat..."
sudo cp "$table_path" "${output_prefix}.dat"

# Disassemble to ASL
echo "Disassembling to ASL ${output_prefix}.dsl..."
# iasl expects options before input file: -d (disassemble), -p (prefix)
sudo iasl -d -p "${output_prefix}" "${output_prefix}.dat"

echo "Done."
echo "Binary: ${output_prefix}.dat"
echo "ASL:    ${output_prefix}.dsl"