119 lines
3.2 KiB
ArmAsm
119 lines
3.2 KiB
ArmAsm
/* -----------------------------------------------------------------------
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*
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* Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use,
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* copy, modify, merge, publish, distribute, sublicense, and/or
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* sell copies of the Software, and to permit persons to whom
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* the Software is furnished to do so, subject to the following
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* conditions:
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*
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* The above copyright notice and this permission notice shall
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* be included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* ----------------------------------------------------------------------- */
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/*
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* COM32 start up code - must be linked first in the binary
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*/
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/* Number of arguments in our version of the entry structure */
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#define COM32_ARGS 9
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.section ".init","ax"
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.globl _start
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.type _start, @function
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_start:
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/* This first instruction acts as COM32R magic number */
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movl $0x21cd4cfe,%eax
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/* Upwards string operations */
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cld
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/* Find our own location */
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call 1f
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1: popl %ebx
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addl $_GLOBAL_OFFSET_TABLE_ + (. - 1b), %ebx
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/* Process relocations (which overlay the .bss segment) */
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leal _edata@GOTOFF(%ebx),%esi
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leal _start@GOTOFF(%ebx),%edx
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2: lodsl
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andl %eax,%eax
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jz 3f
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addl %edx,(%eax,%edx)
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jmp 2b
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3:
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/* Relocate the GOT (is this right?) */
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leal __got_start@GOTOFF(%ebx),%esi
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leal __got_end@GOTOFF(%ebx),%edi
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4:
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addl %edx,(%esi)
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addl $4,%esi
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cmpl %edi,%esi
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jb 4b
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/* Zero the .bss segment */
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xorl %eax,%eax
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leal __bss_start@GOTOFF(%ebx),%edi
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leal _end+3@GOTOFF(%ebx),%ecx
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subl %edi,%ecx
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shrl $2,%ecx
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rep ; stosl
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/* Copy COM32 invocation parameters */
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leal 4(%esp),%esi # Argument list
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leal __com32@GOTOFF(%ebx),%edi
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movl $(COM32_ARGS),%ecx
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movl %esp,-4(%edi) # Save the initial stack ptr
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cmpl (%esi),%ecx
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jbe 5f
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movl (%esi),%ecx
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5: inc %ecx # Copy the argument count, too
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rep ; movsl
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/* Parse the command line (assumes REGPARM) */
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movl __com32+4@GOTOFF(%ebx),%edx # Command line
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pushl %edx # Make space for argv
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movl %esp,%eax
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call __parse_argv
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pushl %eax # Save argc
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/* Look for library initialization functions */
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leal __ctors_start@GOTOFF(%ebx),%esi
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leal __ctors_end@GOTOFF(%ebx),%edi
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6:
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cmpl %edi,%esi
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jae 7f
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call *(%esi)
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addl $4,%esi
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jmp 6b
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/*
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* Actually run main. This assumes REGPARM is used!!!!
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*/
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7:
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popl %eax # argc
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popl %edx # argv
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call main
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call *__exit_handler@GOTOFF(%ebx)
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hlt
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.size _start, .-_start
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.bss
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.globl __entry_esp
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__entry_esp: .space 4
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.globl __com32
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__com32: .space 4*(COM32_ARGS+1)
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