acpi_wakecode.S revision 115681 
1/*-
2 * Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org>
3 * Copyright (c) 2001 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <machine/asm.h>
29__FBSDID("$FreeBSD: head/sys/i386/acpica/acpi_wakecode.S 115681 2003-06-02 06:16:45Z obrien $");
30
31#define LOCORE
32
33#include <machine/specialreg.h>
34
35	.align 4
36	.code16
37wakeup_16:
38	nop
39	cli
40
41	/* Set up segment registers for real mode */
42	movw	%cs,%ax
43	movw	%ax,%ds
44	movw	%ax,%ss
45
46	/* Load GDT for real mode */
47	lgdt	physical_gdt
48
49	/* Restore CR2, CR3 and CR4 */
50	mov	previous_cr2,%eax
51	mov	%eax,%cr2
52	mov	previous_cr3,%eax
53	mov	%eax,%cr3
54	mov	previous_cr4,%eax
55	mov	%eax,%cr4
56
57	/* Transfer some values to protected mode */
58#define NVALUES	9
59#define TRANSFER_STACK32(val, idx)	\
60	mov	val,%eax;		\
61	mov	%eax,wakeup_32stack+(idx+1)+(idx*4);
62
63	TRANSFER_STACK32(previous_ss,		(NVALUES - 9))
64	TRANSFER_STACK32(previous_fs,		(NVALUES - 8))
65	TRANSFER_STACK32(previous_ds,		(NVALUES - 7))
66	TRANSFER_STACK32(physical_gdt+2,	(NVALUES - 6))
67	TRANSFER_STACK32(where_to_recover,	(NVALUES - 5))
68	TRANSFER_STACK32(previous_idt+2,	(NVALUES - 4))
69	TRANSFER_STACK32(previous_ldt,		(NVALUES - 3))
70	TRANSFER_STACK32(previous_gdt+2,	(NVALUES - 2))
71	TRANSFER_STACK32(previous_tr,		(NVALUES - 1))
72	TRANSFER_STACK32(previous_cr0,		(NVALUES - 0))
73
74	mov	physical_esp,%esi	/* to be used in 32bit code */
75
76	/* Enable protected mode */
77	mov	%cr0,%eax
78	orl	$(CR0_PE),%eax
79	mov	%eax,%cr0
80
81wakeup_sw32:
82	/* Switch to protected mode by intersegmental jump */
83	ljmpl	$0x8,$0x12345678	/* Code location, to be replaced */
84
85	.code32
86wakeup_32:
87	/*
88	 * Switched to protected mode w/o paging
89	 *	%esi:	KERNEL stack pointer (physical address)
90	 */
91
92	nop
93
94	/* Set up segment registers for protected mode */
95	movw	$0x10,%ax		/* KDSEL to segment registers */
96	movw	%ax,%ds
97	movw	%ax,%es
98	movw	%ax,%gs
99	movw	%ax,%ss
100	movw	$0x18,%ax		/* KPSEL to %fs */
101	movw	%ax,%fs
102	movl	%esi,%esp		/* physical address stack pointer */
103
104wakeup_32stack:
105	/* Operands are overwritten in 16bit code */
106	pushl	$0xabcdef09		/* ss + dummy */
107	pushl	$0xabcdef08		/* fs + gs */
108	pushl	$0xabcdef07		/* ds + es */
109	pushl	$0xabcdef06		/* gdt:base (physical address) */
110	pushl	$0xabcdef05		/* recover address */
111	pushl	$0xabcdef04		/* idt:base */
112	pushl	$0xabcdef03		/* ldt + idt:limit */
113	pushl	$0xabcdef02		/* gdt:base */
114	pushl	$0xabcdef01		/* TR + gdt:limit */
115	pushl	$0xabcdef00		/* CR0 */
116
117	movl	%esp,%ebp
118#define CR0_REGISTER		0(%ebp)
119#define TASK_REGISTER		4(%ebp)
120#define PREVIOUS_GDT		6(%ebp)
121#define PREVIOUS_LDT		12(%ebp)
122#define PREVIOUS_IDT		14(%ebp)
123#define RECOVER_ADDR		20(%ebp)
124#define PHYSICAL_GDT_BASE	24(%ebp)
125#define PREVIOUS_DS		28(%ebp)
126#define PREVIOUS_ES		30(%ebp)
127#define PREVIOUS_FS		32(%ebp)
128#define PREVIOUS_GS		34(%ebp)
129#define PREVIOUS_SS		36(%ebp)
130
131	/* Fixup TSS type field */
132#define TSS_TYPEFIX_MASK	0xf9
133	xorl	%esi,%esi
134	movl	PHYSICAL_GDT_BASE,%ebx
135	movw	TASK_REGISTER,%si
136	leal	(%ebx,%esi),%eax	/* get TSS segment descriptor */
137	andb	$TSS_TYPEFIX_MASK,5(%eax)
138
139	/* Prepare to return to sleep/wakeup code point */
140	lgdt	PREVIOUS_GDT
141	lidt	PREVIOUS_IDT
142
143	xorl	%eax,%eax
144	movl	%eax,%ebx
145	movl	%eax,%ecx
146	movl	%eax,%edx
147	movl	%eax,%esi
148	movl	%eax,%edi
149	movl	PREVIOUS_DS,%ebx
150	movl	PREVIOUS_FS,%ecx
151	movl	PREVIOUS_SS,%edx
152	movw	TASK_REGISTER,%si
153	shll	$16,%esi
154	movw	PREVIOUS_LDT,%si
155	movl	RECOVER_ADDR,%edi
156
157	/* Enable paging and etc. */
158	movl	CR0_REGISTER,%eax
159	movl	%eax,%cr0
160
161	/* Flush the prefetch queue */
162	jmp	1f
1631:	jmp	1f
1641:
165	/*
166	 * Now that we are in kernel virtual memory addressing
167	 *	%ebx:	ds + es
168	 *	%ecx:	fs + gs
169	 *	%edx:	ss + dummy
170	 *	%esi:	LDTR + TR
171	 *	%edi:	recover address
172	 */
173
174	nop
175
176	movl	%esi,%eax		/* LDTR + TR */
177	lldt	%ax			/* load LDT register */
178	shrl	$16,%eax
179	ltr	%ax			/* load task register */
180
181	/* Restore segment registers */
182	movl	%ebx,%eax		/* ds + es */
183	movw	%ax,%ds
184	shrl	$16,%eax
185	movw	%ax,%es
186	movl	%ecx,%eax		/* fs + gs */
187	movw	%ax,%fs
188	shrl	$16,%eax
189	movw	%ax,%gs
190	movl	%edx,%eax		/* ss */
191	movw	%ax,%ss
192
193	/* Jump to acpi_restorecpu() */
194	jmp	*%edi
195
196/* used in real mode */
197physical_gdt:		.word 0
198			.long 0
199physical_esp:		.long 0
200previous_cr2:		.long 0
201previous_cr3:		.long 0
202previous_cr4:		.long 0
203
204/* transfer from real mode to protected mode */
205previous_cr0:		.long 0
206previous_tr:		.word 0
207previous_gdt:		.word 0
208			.long 0
209previous_ldt:		.word 0
210previous_idt:		.word 0
211			.long 0
212where_to_recover:	.long 0
213previous_ds:		.word 0
214previous_es:		.word 0
215previous_fs:		.word 0
216previous_gs:		.word 0
217previous_ss:		.word 0
218dummy:			.word 0
219
220