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/*
* Copyright (C) 2008 Daniel Verkamp <daniel@drv.nu>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER )
.text
.arch i386
.code32
/*
* This code is entered after running the following sequence out of
* the interrupt jump buffer:
*
* pushal
* movb $vector, %al
* jmp com32_irq_wrapper
*/
.globl com32_irq_wrapper
com32_irq_wrapper:
movzbl %al,%eax
pushl %eax
movl $com32_irq, %eax
call com32_wrapper
popl %eax
popal
iret
.globl com32_farcall_wrapper
com32_farcall_wrapper:
movl $com32_farcall, %eax
jmp com32_wrapper
.globl com32_cfarcall_wrapper
com32_cfarcall_wrapper:
movl $com32_cfarcall, %eax
jmp com32_wrapper
.globl com32_intcall_wrapper
com32_intcall_wrapper:
movl $com32_intcall, %eax
/*jmp com32_wrapper*/ /* fall through */
com32_wrapper:
cli
/* Switch to internal virtual address space */
call _phys_to_virt
/* Switch to internal IDT (if we have one for debugging) */
lidt com32_internal_idtr
mov %eax, (com32_helper_function)
/* Save external COM32 stack pointer */
movl %esp, (com32_external_esp)
/* Copy arguments to caller-save registers */
movl 12(%esp), %eax
movl 8(%esp), %ecx
movl 4(%esp), %edx
/* Switch to internal stack */
movl (com32_internal_esp), %esp
/* Copy arguments to internal stack */
pushl %eax
pushl %ecx
pushl %edx
call *(com32_helper_function)
/* Clean up stack */
addl $12, %esp
/* Save internal stack pointer and restore external stack pointer */
movl %esp, (com32_internal_esp)
movl (com32_external_esp), %esp
/* Switch to com32 IDT */
lidt com32_external_idtr
/* Switch to external flat physical address space */
call _virt_to_phys
sti
ret
.data
/* Internal iPXE virtual address space %esp */
.globl com32_internal_esp
.lcomm com32_internal_esp, 4
/* External flat physical address space %esp */
.globl com32_external_esp
.lcomm com32_external_esp, 4
/* Function pointer of helper to call */
.lcomm com32_helper_function, 4
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