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; i386-darwin.dylib-entry.S -- program entry point & decompressor (i386 Mach-o)
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; This file is part of the UPX executable compressor.
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; Copyright (C) 1996-2009 Markus Franz Xaver Johannes Oberhumer
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; Copyright (C) 1996-2009 Laszlo Molnar
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; Copyright (C) 2000-2009 John F. Reiser
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; UPX and the UCL library are free software; you can redistribute them
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; and/or modify them under the terms of the GNU General Public License as
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; published by the Free Software Foundation; either version 2 of
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; the License, or (at your option) any later version.
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; This program is distributed in the hope that it will be useful,
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; but WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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; GNU General Public License for more details.
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; You should have received a copy of the GNU General Public License
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; along with this program; see the file COPYING.
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; If not, write to the Free Software Foundation, Inc.,
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; 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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; Markus F.X.J. Oberhumer Laszlo Molnar
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; <markus@oberhumer.com> <ml1050@users.sourceforge.net>
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; <jreiser@users.sourceforge.net>
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#include "arch/i386/macros.S"
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/*************************************************************************
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// We have been CALLed as a subroutine from dyld; C-language rules apply.
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// -4*4+_start: .long offset(user_init_function)
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// -3*4+_start: .long offset(&b_info of compressed Mach_headers)
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// -2*4+_start: .long length(compressed __TEXT)
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// -1*4+_start: .long total_length # of preceding bytes in file
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**************************************************************************/
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//// int3 # for debug only
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push eax # space for &user_init_function
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call main // push address of decompress subroutine
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// /*************************************************************************
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// // C callable decompressor
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// **************************************************************************/
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// /* Offsets to parameters, allowing for {pusha + call} */
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#define O_INP (8*4 +1*4)
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#define O_INS (8*4 +2*4)
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#define O_OUTP (8*4 +3*4)
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#define O_OUTS (8*4 +4*4)
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#define O_PARAM (8*4 +5*4)
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#define INP dword ptr [esp+O_INP]
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#define INS dword ptr [esp+O_INS]
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#define OUTP dword ptr [esp+O_OUTP]
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#define OUTS dword ptr [esp+O_OUTS]
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#define PARM dword ptr [esp+O_PARAM]
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//; empty section for commonality with l_lx_exec86.asm
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#include "arch/i386/nrv2b_d32.S"
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#include "arch/i386/nrv2d_d32.S"
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#include "arch/i386/nrv2e_d32.S"
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#include "arch/i386/lzma_d.S"
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// eax is 0 from decompressor code
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//xor eax, eax ; return code
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// check compressed size
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// write back the uncompressed size
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#define PAGE_SIZE ( 1<<12)
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seg_vmsize=4+seg_vmaddr
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seg_filesize=2*4+seg_vmsize
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#define MAP_FIXED 0x10
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#define MAP_PRIVATE 0x02
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#define MAP_ANON 0x1000
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pop ebp # &decompress
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lea ebx,[-4+ _start - decompress + ebp] # &total_length
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mov eax,[-1*4 + ebx] # length(compressed __TEXT)
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add eax,offset(dy_top)
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sub eax,offset(decompress)
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push eax # length for eventual munmap
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push 0 # hi32(offset)
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push 0 # lo32(offset)
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push MAP_ANON|MAP_PRIVATE
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push PROT_READ|PROT_WRITE
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push eax # addr for eventual munmap
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// Copy interval [decompress, dy_top).
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mov esi,ebp # decompressor
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mov ebp,eax # new location
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mov edi,eax # dst for decompressor
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mov ecx,offset(dy_top)
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sub ecx,offset(decompress)
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// Goto the copied dy_reloc.
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lea eax,[-offset(dy_top - dy_reloc) + edi]
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// Copy compressed __TEXT.
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push edi # remember start of compressed __TEXT
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mov edx,ebx # &total_length
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mov eax,[-3*4+ebx] # offset(user_init_function)
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sub edx,[ebx] # runtime base address
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add eax,edx; mov [(1+2+8)*4 + esp],eax # relocate &user_init_function
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mov esi,[-2*4 + ebx]; add esi,edx
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pop esi # &b_info for Mach_header
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mov edi,edx # runtime base address
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// Decompress __TEXT, but do not overwrite Mach_headers
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// in order to maintain consistency with dyld partial caching of them.
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// So, skip the first compressed block.
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lodsd; add edi,eax # sz_unc
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lodsd; add esi,eax # sz_cpr
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push esi; push edi # save in case unfilter
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lodsd; test eax,eax; jz dy_done
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push eax // sz_uncompressed (maximum dstlen for lzma)
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mov ecx,esp // save &dstlen
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push eax // space for 5th param b_info.misc
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add edi,eax // next dst
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lodsd; push eax // sz_compressed (srclen)
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lodsd; mov [3*4 + esp],eax // last 4 bytes of b_info
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push esi // &compressed __TEXT
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add esi,ecx // next src
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call ebp // decompress(src, srclen, dst, &dstlen, b_info.misc)
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add esp, (5+1)*4 // (5+1) args to decompress
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pop edx; pop eax # edx= old dst; eax= old &b_info
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movzbl ecx,[1+ b_method + eax]; jecxz dy_uncpr; push ecx # ftid
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movzbl ecx,[2+ b_method + eax]; push ecx # cto8
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lea eax,[2+ ebp]; call eax # f_unfilter(dst, dstlen, cto8, ftid)
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call sysgo; jncs 0f; or eax,~0
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pop eax # discard, leaving 1 junk word below the regs for POPA
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lea edx,[-5+ edi] # steal some space at high end of __TEXT
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mov byte ptr [ edx], 0x58 # pop eax
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mov dword ptr [1+ edx],0xc3615858 # pop eax; pop eax; popa; ret
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pop edx # return address for sysenter
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mov ecx,esp # &{user_ret, arg1, arg2, ...}
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.byte 0x0f, 0x34 # sysenter
added
removed
src/stub/src/i386-darwin.dylib-entry.S
