1/* -----------------------------------------------------------------------
 2 *
 3 *   Copyright 2009-2014 Intel Corporation; author H. Peter Anvin
 4 *
 5 *   This file is part of the Linux kernel, and is made available under
 6 *   the terms of the GNU General Public License version 2 or (at your
 7 *   option) any later version; incorporated herein by reference.
 8 *
 9 * ----------------------------------------------------------------------- */
10
11/*
12 * "Glove box" for BIOS calls.  Avoids the constant problems with BIOSes
13 * touching registers they shouldn't be.
14 */
15
16	.code16
17	.section ".inittext","ax"
18	.globl	intcall
19	.type	intcall, @function
20intcall:
21	/* Self-modify the INT instruction.  Ugly, but works. */
22	cmpb	%al, 3f
23	je	1f
24	movb	%al, 3f
25	jmp	1f		/* Synchronize pipeline */
261:
27	/* Save state */
28	pushfl
29	pushw	%fs
30	pushw	%gs
31	pushal
32
33	/* Copy input state to stack frame */
34	subw	$44, %sp
35	movw	%dx, %si
36	movw	%sp, %di
37	movw	$11, %cx
38	rep; movsd
39
40	/* Pop full state from the stack */
41	popal
42	popw	%gs
43	popw	%fs
44	popw	%es
45	popw	%ds
46	popfl
47
48	/* Actual INT */
49	.byte	0xcd		/* INT opcode */
503:	.byte	0
51
52	/* Push full state to the stack */
53	pushfl
54	pushw	%ds
55	pushw	%es
56	pushw	%fs
57	pushw	%gs
58	pushal
59
60	/* Re-establish C environment invariants */
61	cld
62	movzwl	%sp, %esp
63	movw	%cs, %ax
64	movw	%ax, %ds
65	movw	%ax, %es
66
67	/* Copy output state from stack frame */
68	movw	68(%esp), %di	/* Original %cx == 3rd argument */
69	andw	%di, %di
70	jz	4f
71	movw	%sp, %si
72	movw	$11, %cx
73	rep; movsd
744:	addw	$44, %sp
75
76	/* Restore state and return */
77	popal
78	popw	%gs
79	popw	%fs
80	popfl
81	retl
82	.size	intcall, .-intcall

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/* -----------------------------------------------------------------------
 3 *
 4 *   Copyright 2009-2014 Intel Corporation; author H. Peter Anvin
 5 *
 
 
 
 
 6 * ----------------------------------------------------------------------- */
 7
 8/*
 9 * "Glove box" for BIOS calls.  Avoids the constant problems with BIOSes
10 * touching registers they shouldn't be.
11 */
12
13	.code16
14	.section ".inittext","ax"
15	.globl	intcall
16	.type	intcall, @function
17intcall:
18	/* Self-modify the INT instruction.  Ugly, but works. */
19	cmpb	%al, 3f
20	je	1f
21	movb	%al, 3f
22	jmp	1f		/* Synchronize pipeline */
231:
24	/* Save state */
25	pushfl
26	pushw	%fs
27	pushw	%gs
28	pushal
29
30	/* Copy input state to stack frame */
31	subw	$44, %sp
32	movw	%dx, %si
33	movw	%sp, %di
34	movw	$11, %cx
35	rep; movsl
36
37	/* Pop full state from the stack */
38	popal
39	popw	%gs
40	popw	%fs
41	popw	%es
42	popw	%ds
43	popfl
44
45	/* Actual INT */
46	.byte	0xcd		/* INT opcode */
473:	.byte	0
48
49	/* Push full state to the stack */
50	pushfl
51	pushw	%ds
52	pushw	%es
53	pushw	%fs
54	pushw	%gs
55	pushal
56
57	/* Re-establish C environment invariants */
58	cld
59	movzwl	%sp, %esp
60	movw	%cs, %ax
61	movw	%ax, %ds
62	movw	%ax, %es
63
64	/* Copy output state from stack frame */
65	movw	68(%esp), %di	/* Original %cx == 3rd argument */
66	andw	%di, %di
67	jz	4f
68	movw	%sp, %si
69	movw	$11, %cx
70	rep; movsl
714:	addw	$44, %sp
72
73	/* Restore state and return */
74	popal
75	popw	%gs
76	popw	%fs
77	popfl
78	retl
79	.size	intcall, .-intcall