xref: /freebsd/sys/i386/i386/mpboot.S (revision 95ee2897) 
1/*-
2 * Copyright (c) 1995 Jack F. Vogel
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * mpboot.s:	FreeBSD machine support for the Intel MP Spec
27 *		multiprocessor systems.
28 */
29
30#include "opt_pmap.h"
31
32#include <machine/asmacros.h>		/* miscellaneous asm macros */
33#include <x86/apicreg.h>
34#include <machine/specialreg.h>
35
36#include "assym.inc"
37
38/*
39 * this code MUST be enabled here and in mp_machdep.c
40 * it follows the very early stages of AP boot by placing values in CMOS ram.
41 * it NORMALLY will never be needed and thus the primitive method for enabling.
42 *
43#define CHECK_POINTS
44 */
45
46#if defined(CHECK_POINTS)
47
48#define CMOS_REG	(0x70)
49#define CMOS_DATA	(0x71)
50
51#define CHECKPOINT(A,D)		\
52	movb	$(A),%al ;	\
53	outb	%al,$CMOS_REG ;	\
54	movb	$(D),%al ;	\
55	outb	%al,$CMOS_DATA
56
57#else
58
59#define CHECKPOINT(A,D)
60
61#endif /* CHECK_POINTS */
62
63
64/*
65 * the APs enter here from their trampoline code (bootMP, below)
66 */
67	.p2align 4
68
69ENTRY(MPentry)
70	CHECKPOINT(0x36, 3)
71	/*
72	 * Enable features on this processor.  We don't support SMP on
73	 * CPUs older than a Pentium, so we know that we can use the cpuid
74	 * instruction.
75	 */
76	movl	$1,%eax
77	cpuid					/* Retrieve features */
78	movl	%cr4,%eax
79	testl	$CPUID_PSE,%edx
80	jz 1f
81	orl	$CR4_PSE,%eax			/* Enable PSE  */
821:	testl	$CPUID_PGE,%edx
83	jz 2f
84	orl	$CR4_PGE,%eax			/* Enable PGE  */
852:	testl	$CPUID_VME,%edx
86	jz 3f
87	orl	$CR4_VME,%eax			/* Enable VME  */
883:	movl	%eax,%cr4
89
90	/* Now enable paging mode */
91	cmpl	$0, pae_mode
92	je	4f
93	movl	IdlePDPT, %eax
94	movl	%eax, %cr3
95	movl	%cr4, %eax
96	orl	$CR4_PAE, %eax
97	movl	%eax, %cr4
98	movl	$0x80000000, %eax
99	cpuid
100	movl	$0x80000001, %ebx
101	cmpl	%ebx, %eax
102	jb	5f
103	movl	%ebx, %eax
104	cpuid
105	testl	$AMDID_NX, %edx
106	je	5f
107	movl	$MSR_EFER, %ecx
108	rdmsr
109	orl	$EFER_NXE,%eax
110	wrmsr
111	jmp	5f
1124:	movl	IdlePTD_nopae, %eax
113	movl	%eax,%cr3
1145:	movl	%cr0,%eax
115	orl	$CR0_PE|CR0_PG,%eax		/* enable paging */
116	movl	%eax,%cr0			/* let the games begin! */
117	movl	bootSTK,%esp			/* boot stack end loc. */
118
119	pushl	$mp_begin			/* jump to high mem */
120	ret
121
122	/*
123	 * Wait for the booting CPU to signal startup
124	 */
125mp_begin:	/* now running relocated at KERNBASE */
126	CHECKPOINT(0x37, 4)
127	call	init_secondary			/* load i386 tables */
128
129/*
130 * This is the embedded trampoline or bootstrap that is
131 * copied into 'real-mode' low memory, it is where the
132 * secondary processor "wakes up". When it is executed
133 * the processor will eventually jump into the routine
134 * MPentry, which resides in normal kernel text above
135 * 1Meg.		-jackv
136 */
137
138	.data
139	ALIGN_DATA				/* just to be sure */
140
141BOOTMP1:
142
143ENTRY(bootMP)
144	.code16
145	cli
146	CHECKPOINT(0x34, 1)
147	/* First guarantee a 'clean slate' */
148	xorl	%eax, %eax
149	movl	%eax, %ebx
150	movl	%eax, %ecx
151 	movl	%eax, %edx
152	movl	%eax, %esi
153	movl	%eax, %edi
154
155	/* set up data segments */
156	mov	%cs, %ax
157	mov	%ax, %ds
158	mov	%ax, %es
159	mov	%ax, %fs
160	mov	%ax, %gs
161	mov	%ax, %ss
162	mov	$(boot_stk-bootMP), %esp
163
164	/* Now load the global descriptor table */
165	lgdt	MP_GDTptr-bootMP
166
167	/* Enable protected mode */
168	movl	%cr0, %eax
169	orl	$CR0_PE, %eax
170	movl	%eax, %cr0
171
172	/*
173	 * make intrasegment jump to flush the processor pipeline and
174	 * reload CS register
175	 */
176	pushl	$0x18
177	pushl	$(protmode-bootMP)
178	lretl
179
180       .code32
181protmode:
182	CHECKPOINT(0x35, 2)
183
184	/*
185	 * we are NOW running for the first time with %eip
186	 * having the full physical address, BUT we still
187	 * are using a segment descriptor with the origin
188	 * not matching the booting kernel.
189	 *
190 	 * SO NOW... for the BIG Jump into kernel's segment
191	 * and physical text above 1 Meg.
192	 */
193	mov	$0x10, %ebx
194	movw	%bx, %ds
195	movw	%bx, %es
196	movw	%bx, %fs
197	movw	%bx, %gs
198	movw	%bx, %ss
199
200	.globl	bigJump
201bigJump:
202	/* this will be modified by mpInstallTramp() */
203	ljmp	$0x08, $0			/* far jmp to MPentry() */
204
205dead:	hlt /* We should never get here */
206	jmp	dead
207
208/*
209 * MP boot strap Global Descriptor Table
210 */
211	.p2align 4
212	.globl	MP_GDT
213	.globl	bootCodeSeg
214	.globl	bootDataSeg
215MP_GDT:
216
217nulldesc:		/* offset = 0x0 */
218
219	.word	0x0
220	.word	0x0
221	.byte	0x0
222	.byte	0x0
223	.byte	0x0
224	.byte	0x0
225
226kernelcode:		/* offset = 0x08 */
227
228	.word	0xffff	/* segment limit 0..15 */
229	.word	0x0000	/* segment base 0..15 */
230	.byte	0x0	/* segment base 16..23; set for 0K */
231	.byte	0x9f	/* flags; Type	*/
232	.byte	0xcf	/* flags; Limit	*/
233	.byte	0x0	/* segment base 24..32 */
234
235kerneldata:		/* offset = 0x10 */
236
237	.word	0xffff	/* segment limit 0..15 */
238	.word	0x0000	/* segment base 0..15 */
239	.byte	0x0	/* segment base 16..23; set for 0k */
240	.byte	0x93	/* flags; Type  */
241	.byte	0xcf	/* flags; Limit */
242	.byte	0x0	/* segment base 24..32 */
243
244bootcode:		/* offset = 0x18 */
245
246	.word	0xffff	/* segment limit 0..15 */
247bootCodeSeg:		/* this will be modified by mpInstallTramp() */
248	.word	0x0000	/* segment base 0..15 */
249	.byte	0x00	/* segment base 16...23; set for 0x000xx000 */
250	.byte	0x9e	/* flags; Type  */
251	.byte	0xcf	/* flags; Limit */
252	.byte	0x0	/*segment base 24..32 */
253
254bootdata:		/* offset = 0x20 */
255
256	.word	0xffff
257bootDataSeg:		/* this will be modified by mpInstallTramp() */
258	.word	0x0000	/* segment base 0..15 */
259	.byte	0x00	/* segment base 16...23; set for 0x000xx000 */
260	.byte	0x92
261	.byte	0xcf
262	.byte	0x0
263
264/*
265 * GDT pointer for the lgdt call
266 */
267	.globl	mp_gdtbase
268
269MP_GDTptr:
270mp_gdtlimit:
271	.word	0x0028
272mp_gdtbase:		/* this will be modified by mpInstallTramp() */
273	.long	0
274
275	.space	0x100	/* space for boot_stk - 1st temporary stack */
276boot_stk:
277
278BOOTMP2:
279	.globl	bootMP_size
280bootMP_size:
281	.long	BOOTMP2 - BOOTMP1
282