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