xref: /freebsd/sys/i386/acpica/acpi_wakecode.S (revision 6f9c8e5b074419423648ffb89b83fd2f257e90b7)
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 * $FreeBSD$
28 */
29
30#include <machine/asmacros.h>
31#include <machine/specialreg.h>
32
33#include "assym.s"
34
35/*
36 * Resume entry point.  The BIOS enters here in real mode after POST with
37 * CS set to the page where we stored this code.  It should configure the
38 * segment registers with a flat 4 GB address space and EFLAGS.IF = 0.
39 * Depending on the previous sleep state, we may need to initialize more
40 * of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk).
41 */
42	.align 4
43	.code16
44wakeup_16:
45	nop
46	cli
47	cld
48
49	/*
50	 * Set up segment registers for real mode, a small stack for
51	 * any calls we make, and clear any flags.
52	 */
53	movw	%cs,%ax
54	movw	%ax,%ds
55	movw	%ax,%ss
56	movw	$PAGE_SIZE,%sp
57	pushl	$0
58	popfl
59
60	/* To debug resume hangs, beep the speaker if the user requested. */
61	cmpl	$1,resume_beep
62	jne	nobeep
63	movb	$0xc0,%al
64	outb	%al,$0x42
65	movb	$0x04,%al
66	outb	%al,$0x42
67	inb	$0x61,%al
68	orb	$0x3,%al
69	outb	%al,$0x61
70nobeep:
71
72	/* Re-initialize video BIOS if the reset_video tunable is set. */
73	cmpl	$1,reset_video
74	jne	nobiosreset
75	lcall	$0xc000,$3
76
77	/*
78	 * Set up segment registers for real mode again in case the
79	 * previous BIOS call clobbers them.
80	 */
81	movw	%cs,%ax
82	movw	%ax,%ds
83	movw	%ax,%ss
84nobiosreset:
85
86	/* Load GDT for real mode.  Use 32 bit prefix for addresses >16 MB. */
87	lgdtl	physical_gdt
88
89	/* Restore CR2, CR3 and CR4 */
90	movl	previous_cr2,%eax
91	movl	%eax,%cr2
92	movl	previous_cr3,%eax
93	movl	%eax,%cr3
94	movl	previous_cr4,%eax
95	movl	%eax,%cr4
96
97	/* Transfer some values to protected mode with an inline stack */
98#define NVALUES	9
99#define TRANSFER_STACK32(val, idx)	\
100	movl	val,%eax;		\
101	movl	%eax,wakeup_32stack+(idx+1)+(idx*4)
102
103	TRANSFER_STACK32(previous_ss,		(NVALUES - 9))
104	TRANSFER_STACK32(previous_fs,		(NVALUES - 8))
105	TRANSFER_STACK32(previous_ds,		(NVALUES - 7))
106	TRANSFER_STACK32(physical_gdt+2,	(NVALUES - 6))
107	TRANSFER_STACK32(where_to_recover,	(NVALUES - 5))
108	TRANSFER_STACK32(previous_idt+2,	(NVALUES - 4))
109	TRANSFER_STACK32(previous_ldt,		(NVALUES - 3))
110	TRANSFER_STACK32(previous_gdt+2,	(NVALUES - 2))
111	TRANSFER_STACK32(previous_tr,		(NVALUES - 1))
112	TRANSFER_STACK32(previous_cr0,		(NVALUES - 0))
113
114	mov	physical_esp,%esi	/* to be used in 32bit code */
115
116	/* Enable protected mode */
117	movl	%cr0,%eax
118	orl	$(CR0_PE),%eax
119	movl	%eax,%cr0
120
121wakeup_sw32:
122	/* Switch to protected mode by intersegmental jump */
123	ljmpl	$KCSEL,$0x12345678	/* Code location, to be replaced */
124
125	/*
126	 * Now switched to protected mode without paging enabled.
127	 *	%esi: KERNEL stack pointer (physical address)
128	 */
129	.code32
130wakeup_32:
131	nop
132
133	/* Set up segment registers for protected mode */
134	movw	$KDSEL,%ax		/* KDSEL to segment registers */
135	movw	%ax,%ds
136	movw	%ax,%es
137	movw	%ax,%gs
138	movw	%ax,%ss
139	movw	$KPSEL,%ax		/* KPSEL to %fs */
140	movw	%ax,%fs
141	movl	%esi,%esp		/* physical address stack pointer */
142
143wakeup_32stack:
144	/* Operands are overwritten in 16 bit code by TRANSFER_STACK32 macro */
145	pushl	$0xabcdef09		/* ss + dummy */
146	pushl	$0xabcdef08		/* fs + gs */
147	pushl	$0xabcdef07		/* ds + es */
148	pushl	$0xabcdef06		/* gdt:base (physical address) */
149	pushl	$0xabcdef05		/* recover address */
150	pushl	$0xabcdef04		/* idt:base */
151	pushl	$0xabcdef03		/* ldt + idt:limit */
152	pushl	$0xabcdef02		/* gdt:base */
153	pushl	$0xabcdef01		/* TR + gdt:limit */
154	pushl	$0xabcdef00		/* CR0 */
155
156	movl	%esp,%ebp
157#define CR0_REGISTER		0(%ebp)
158#define TASK_REGISTER		4(%ebp)
159#define PREVIOUS_GDT		6(%ebp)
160#define PREVIOUS_LDT		12(%ebp)
161#define PREVIOUS_IDT		14(%ebp)
162#define RECOVER_ADDR		20(%ebp)
163#define PHYSICAL_GDT_BASE	24(%ebp)
164#define PREVIOUS_DS		28(%ebp)
165#define PREVIOUS_ES		30(%ebp)
166#define PREVIOUS_FS		32(%ebp)
167#define PREVIOUS_GS		34(%ebp)
168#define PREVIOUS_SS		36(%ebp)
169
170	/* Fixup TSS type field */
171#define TSS_TYPEFIX_MASK	0xf9
172	xorl	%esi,%esi
173	movl	PHYSICAL_GDT_BASE,%ebx
174	movw	TASK_REGISTER,%si
175	leal	(%ebx,%esi),%eax	/* get TSS segment descriptor */
176	andb	$TSS_TYPEFIX_MASK,5(%eax)
177
178	/* Prepare to return to sleep/wakeup code point */
179	lgdtl	PREVIOUS_GDT
180	lidtl	PREVIOUS_IDT
181
182	/* Pack values from the GDT to be loaded into segment registers. */
183	movl	PREVIOUS_DS,%ebx
184	movl	PREVIOUS_FS,%ecx
185	movl	PREVIOUS_SS,%edx
186	movw	TASK_REGISTER,%si
187	shll	$16,%esi
188	movw	PREVIOUS_LDT,%si
189	movl	RECOVER_ADDR,%edi
190
191	/* Enable paging and etc. */
192	movl	CR0_REGISTER,%eax
193	movl	%eax,%cr0
194
195	/* Flush the prefetch queue */
196	jmp	1f
1971:	jmp	1f
1981:
199
200	/*
201	 * Now we are in kernel virtual memory addressing with the following
202	 * original register values:
203	 *	%ebx: ds + es
204	 *	%ecx: fs + gs
205	 *	%edx: ss + dummy
206	 *	%esi: LDTR + TR
207	 *	%edi: recover address
208	 * We'll load these back into the segment registers now.
209	 */
210	nop
211
212	movl	%esi,%eax		/* LDTR + TR */
213	lldt	%ax			/* load LDT register */
214	shrl	$16,%eax
215	ltr	%ax			/* load task register */
216
217	/* Restore segment registers */
218	movl	%ebx,%eax		/* ds + es */
219	movw	%ax,%ds
220	shrl	$16,%eax
221	movw	%ax,%es
222	movl	%ecx,%eax		/* fs + gs */
223	movw	%ax,%fs
224	shrl	$16,%eax
225	movw	%ax,%gs
226	movl	%edx,%eax		/* ss */
227	movw	%ax,%ss
228
229	/* Jump to acpi_restorecpu() */
230	jmp	*%edi
231
232/* used in real mode */
233physical_gdt:		.word 0
234			.long 0
235physical_esp:		.long 0
236previous_cr2:		.long 0
237previous_cr3:		.long 0
238previous_cr4:		.long 0
239resume_beep:		.long 0
240reset_video:		.long 0
241
242/*
243 * Transfer from real mode to protected mode.  The order of these variables
244 * is very important, DO NOT INSERT OR CHANGE unless you know why.
245 */
246previous_cr0:		.long 0
247previous_tr:		.word 0
248previous_gdt:		.word 0
249			.long 0
250previous_ldt:		.word 0
251previous_idt:		.word 0
252			.long 0
253where_to_recover:	.long 0
254previous_ds:		.word 0
255previous_es:		.word 0
256previous_fs:		.word 0
257previous_gs:		.word 0
258previous_ss:		.word 0
259dummy:			.word 0
260