Acelogic
1510d8c6ce
An EL2 monitor/hypervisor and toolchain that boots macOS 27 on the ASUS A16 (Snapdragon X2 Elite), with an Adreno Metal plug-in and IOGPU kext, and air2ir3, an AIR to Mesa ir3 shader compiler. MIT, with GPL-2.0 components listed in LICENSE and THIRD_PARTY_NOTICES.md. No Apple, Qualcomm, ASUS or Microsoft binaries are included.
103 lines
3.8 KiB
Python
Executable File
103 lines
3.8 KiB
Python
Executable File
#!/usr/bin/env python3
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# SPDX-License-Identifier: MIT
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"""A BSDIFF40 patch for /usr/bin/bspatch, from block matches (no suffix sort).
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python3 tools/bsdiff-lite.py OLD NEW PATCH
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The format is bsdiff 4.3's (header, then bzip2'd control, diff and extra blocks), so any bspatch applies it. Matches
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are found only on 16-byte-aligned 32-byte blocks of OLD and extended both ways, so the patch is small only when NEW
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is mostly OLD's bytes, possibly shifted: a rebuilt binary with an unchanged data payload. The patch is applied with
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/usr/bin/bspatch before it is written, and must reproduce NEW exactly; otherwise nothing is written.
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"""
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import bz2
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from pathlib import Path
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import subprocess
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import sys
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import tempfile
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BLOCK, STEP = 32, 16
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def offtout(x):
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"""bsdiff's int64: sign-magnitude, little-endian, sign in bit 63."""
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return (abs(x) | (1 << 63 if x < 0 else 0)).to_bytes(8, 'little')
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def segments(old, new):
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"""NEW as ('copy', old offset, length) and ('lit', bytes) runs, in order."""
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index = {}
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for i in range(0, len(old) - BLOCK + 1, STEP):
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index.setdefault(old[i:i + BLOCK], i)
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out, lit_start, p = [], 0, 0
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while p + BLOCK <= len(new):
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o = index.get(new[p:p + BLOCK])
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if o is None:
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p += 1
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continue
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start, ostart = p, o
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while start > lit_start and ostart > 0 and new[start - 1] == old[ostart - 1]:
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start, ostart = start - 1, ostart - 1
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end, oend = p + BLOCK, o + BLOCK
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while end < len(new) and oend < len(old) and new[end] == old[oend]:
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end, oend = end + 1, oend + 1
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if start > lit_start:
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out.append(('lit', new[lit_start:start]))
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out.append(('copy', ostart, end - start))
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lit_start = p = end
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if lit_start < len(new):
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out.append(('lit', new[lit_start:]))
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return out
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def patch(old, new):
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"""bspatch reads (x, y, z): x bytes of old+diff at oldpos, y bytes of extra, then oldpos += x + z."""
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segs = segments(old, new)
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ctrl, diff, extra = bytearray(), bytearray(), bytearray()
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oldpos = newpos = i = 0
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if segs and segs[0][0] == 'copy' and segs[0][1]:
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ctrl += offtout(0) + offtout(0) + offtout(segs[0][1]) # seek old to the first copy
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oldpos = segs[0][1]
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while i < len(segs):
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x = 0
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if segs[i][0] == 'copy':
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_, at, x = segs[i]
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assert at == oldpos, (at, oldpos)
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diff += bytes((a - b) & 0xFF for a, b in zip(new[newpos:newpos + x], old[at:at + x]))
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newpos, oldpos, i = newpos + x, oldpos + x, i + 1
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y = b''
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if i < len(segs) and segs[i][0] == 'lit':
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y = segs[i][1]
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newpos, i = newpos + len(y), i + 1
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nxt = segs[i][1] if i < len(segs) and segs[i][0] == 'copy' else oldpos
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ctrl += offtout(x) + offtout(len(y)) + offtout(nxt - oldpos)
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extra += y
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oldpos = nxt
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assert newpos == len(new)
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c, d, e = (bz2.compress(bytes(b), 9) for b in (ctrl, diff, extra))
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return b'BSDIFF40' + offtout(len(c)) + offtout(len(d)) + offtout(len(new)) + c + d + e
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def main():
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if len(sys.argv) != 4:
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print(__doc__)
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return 64
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old, new, out = Path(sys.argv[1]).read_bytes(), Path(sys.argv[2]).read_bytes(), Path(sys.argv[3])
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if out.exists():
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print(f'{out} exists')
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return 64
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data = patch(old, new)
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with tempfile.TemporaryDirectory() as tmp:
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p, r = Path(tmp) / 'patch', Path(tmp) / 'result'
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p.write_bytes(data)
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subprocess.run(['/usr/bin/bspatch', sys.argv[1], str(r), str(p)], check=True)
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if r.read_bytes() != new:
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print('FAIL: bspatch did not reproduce NEW')
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return 1
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out.write_bytes(data)
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print(f'patch {len(data)} bytes for {len(new)} new bytes; /usr/bin/bspatch reproduces NEW exactly')
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return 0
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if __name__ == '__main__':
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sys.exit(main())
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