#!/usr/bin/env python3
# Simple kernel symbol dumper
# Usage: ksyms.py --input <kernel binary> --output <output file>

import sys
import subprocess
import argparse

excluded_symbols = ['text_start_addr', 'text_end_addr', 'rodata_start_addr', 'rodata_end_addr', 'data_start_addr', 'data_end_addr']

def parse_nm_line(line: str) -> tuple[int, str]:
    parts = line.split()
    if len(parts) < 3:
        return None

    addr_str, type, name = parts[0], parts[1], parts[2]

    # Only get symbols in text 
    if type.lower() != 't':
        return None
    
    if name in excluded_symbols:
        return None

    addr = int(addr_str, 16)
    return addr, name

def run_nm(binary: str) -> list[str]:

    result = subprocess.run(["nm", "-n", binary], capture_output=True, text=True)
    if result.returncode != 0:
        raise RuntimeError(f"nm failed: {result.stderr}")
    return result.stdout.splitlines()

parser = argparse.ArgumentParser(description="Generate kernel symbols from a binary")
parser.add_argument("--input", help="Input kernel binary")
parser.add_argument("--output", help="Output C file")
parser.add_argument("--empty", action="store_true", help="Generate empty ksyms")
args = parser.parse_args()

if args.empty:
    with open(args.output, 'w') as f:
        f.write("// Auto-generated by build/ksyms.py - do not edit\n\n")
        f.write("pub const KSym = struct {\n    addr: u64,\n    name: []const u8,\n};\n\n")
        f.write("pub const ksyms: []const KSym = &.{};\n")
    sys.exit(0)

lines = run_nm(args.input)

symbols = []
for line in lines:
    parsed = parse_nm_line(line)
    if parsed:
        symbols.append(parsed)
    

# Sort by address
symbols.sort(key=lambda x: x[0])

with open(args.output, 'w') as f:
    f.write("// Auto-generated by build/ksyms.py - do not edit\n\n")
    f.write("pub const KSym = struct {\n    addr: u64,\n    name: []const u8,\n};\n\n")
    f.write("pub const ksyms: []const KSym = &.{\n")
    for addr, name in symbols:
        escaped = name.replace('\\', '\\\\').replace('"', '\\"')
        f.write(f"    .{{ .addr = 0x{addr:016x}, .name = \"{escaped}\" }},\n")
    f.write("};\n")