#!/usr/bin/env python3
"""edp_carve.py — точная нарезка ELF из Emergency Payload (.edp) по program headers.
Использование: ./tools/edp_carve.py fw/dl/edp-archorg-1127.edp out-dir/
"""
import os
import struct
import sys


def elf_span(d, off):
    assert d[off:off + 4] == b"\x7fELF", "not ELF"
    entry = struct.unpack("<I", d[off + 24:off + 28])[0]
    phoff = struct.unpack("<I", d[off + 28:off + 32])[0]
    phnum = struct.unpack("<H", d[off + 44:off + 46])[0]
    end = 0
    segs = []
    for i in range(phnum):
        p = off + phoff + i * 32
        ptype, poff, pv, pp, pfsz, pmsz, flg, al = struct.unpack("<IIIIIIII", d[p:p + 32])
        if ptype == 1:  # PT_LOAD
            segs.append((pv, pfsz, pmsz, flg))
            end = max(end, poff + pfsz)
    return entry, segs, end


def main():
    src, outdir = sys.argv[1], sys.argv[2]
    d = open(src, "rb").read()
    offs = []
    i = 0
    while True:
        i = d.find(b"\x7fELF", i)
        if i < 0:
            break
        offs.append(i)
        i += 1
    os.makedirs(outdir, exist_ok=True)
    print(f"{len(offs)} ELFs")
    for n, o in enumerate(offs):
        try:
            entry, segs, end = elf_span(d, o)
        except Exception as e:
            print(n, f"off={o} PARSE-FAIL {e}")
            continue
        open(f"{outdir}/img{n}.elf", "wb").write(d[o:o + end])
        mem = sum(s[2] for s in segs)
        print(f"img{n}: off={o} size={end} entry={entry:#x} mem={mem} "
              + " ".join(f"[{v:#x}+{ms:#x}{'X' if fl & 1 else ''}]" for v, fz, ms, fl in segs))


if __name__ == "__main__":
    main()