1/*
2 * Copyright (C) 2008 Daniel Verkamp <daniel@drv.nu>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19FILE_LICENCE ( GPL2_OR_LATER )
20
21	.text
22	.arch i386
23	.code32
24
25	.globl com32_farcall_wrapper
26com32_farcall_wrapper:
27
28	movl $com32_farcall, %eax
29	jmp com32_wrapper
30
31
32	.globl com32_cfarcall_wrapper
33com32_cfarcall_wrapper:
34
35	movl $com32_cfarcall, %eax
36	jmp com32_wrapper
37
38
39	.globl com32_intcall_wrapper
40com32_intcall_wrapper:
41
42	movl $com32_intcall, %eax
43	/*jmp com32_wrapper*/ /* fall through */
44
45com32_wrapper:
46
47	/* Switch to internal virtual address space */
48	call _phys_to_virt
49
50	mov %eax, (com32_helper_function)
51
52	/* Save external COM32 stack pointer */
53	movl %esp, (com32_external_esp)
54
55	/* Copy arguments to caller-save registers */
56	movl 12(%esp), %eax
57	movl 8(%esp), %ecx
58	movl 4(%esp), %edx
59
60	/* Switch to internal stack */
61	movl (com32_internal_esp), %esp
62
63	/* Copy arguments to internal stack */
64	pushl %eax
65	pushl %ecx
66	pushl %edx
67
68	call *(com32_helper_function)
69
70	/* Clean up stack */
71	addl $12, %esp
72
73	/* Save internal stack pointer and restore external stack pointer */
74	movl %esp, (com32_internal_esp)
75	movl (com32_external_esp), %esp
76
77	/* Switch to external flat physical address space */
78	call _virt_to_phys
79
80	ret
81
82
83	.data
84
85/* Internal gPXE virtual address space %esp */
86.globl com32_internal_esp
87.lcomm com32_internal_esp, 4
88
89/* External flat physical address space %esp */
90.globl com32_external_esp
91.lcomm com32_external_esp, 4
92
93/* Function pointer of helper to call */
94.lcomm com32_helper_function, 4
95