2 * Copyright (c) 1995 Jack F. Vogel
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
26 * mpboot.s: FreeBSD machine support for the Intel MP Spec
27 * multiprocessor systems.
34 #include <machine/asmacros.h> /* miscellaneous asm macros */
35 #include <x86/apicreg.h>
36 #include <machine/specialreg.h>
41 * this code MUST be enabled here and in mp_machdep.c
42 * it follows the very early stages of AP boot by placing values in CMOS ram.
43 * it NORMALLY will never be needed and thus the primitive method for enabling.
48 #if defined(CHECK_POINTS)
50 #define CMOS_REG (0x70)
51 #define CMOS_DATA (0x71)
53 #define CHECKPOINT(A,D) \
55 outb %al,$CMOS_REG ; \
61 #define CHECKPOINT(A,D)
63 #endif /* CHECK_POINTS */
67 * the APs enter here from their trampoline code (bootMP, below)
74 * Enable features on this processor. We don't support SMP on
75 * CPUs older than a Pentium, so we know that we can use the cpuid
79 cpuid /* Retrieve features */
83 orl $CR4_PSE,%eax /* Enable PSE */
84 1: testl $CPUID_PGE,%edx
86 orl $CR4_PGE,%eax /* Enable PGE */
87 2: testl $CPUID_VME,%edx
89 orl $CR4_VME,%eax /* Enable VME */
92 /* Now enable paging mode */
100 movl $0x80000000, %eax
102 movl $0x80000001, %ebx
107 testl $AMDID_NX, %edx
114 4: movl IdlePTD_nopae, %eax
117 orl $CR0_PE|CR0_PG,%eax /* enable paging */
118 movl %eax,%cr0 /* let the games begin! */
119 movl bootSTK,%esp /* boot stack end loc. */
121 pushl $mp_begin /* jump to high mem */
125 * Wait for the booting CPU to signal startup
127 mp_begin: /* now running relocated at KERNBASE */
129 call init_secondary /* load i386 tables */
132 * This is the embedded trampoline or bootstrap that is
133 * copied into 'real-mode' low memory, it is where the
134 * secondary processor "wakes up". When it is executed
135 * the processor will eventually jump into the routine
136 * MPentry, which resides in normal kernel text above
141 ALIGN_DATA /* just to be sure */
149 /* First guarantee a 'clean slate' */
157 /* set up data segments */
164 mov $(boot_stk-bootMP), %esp
166 /* Now load the global descriptor table */
167 lgdt MP_GDTptr-bootMP
169 /* Enable protected mode */
175 * make intrasegment jump to flush the processor pipeline and
179 pushl $(protmode-bootMP)
187 * we are NOW running for the first time with %eip
188 * having the full physical address, BUT we still
189 * are using a segment descriptor with the origin
190 * not matching the booting kernel.
192 * SO NOW... for the BIG Jump into kernel's segment
193 * and physical text above 1 Meg.
204 /* this will be modified by mpInstallTramp() */
205 ljmp $0x08, $0 /* far jmp to MPentry() */
207 dead: hlt /* We should never get here */
211 * MP boot strap Global Descriptor Table
219 nulldesc: /* offset = 0x0 */
228 kernelcode: /* offset = 0x08 */
230 .word 0xffff /* segment limit 0..15 */
231 .word 0x0000 /* segment base 0..15 */
232 .byte 0x0 /* segment base 16..23; set for 0K */
233 .byte 0x9f /* flags; Type */
234 .byte 0xcf /* flags; Limit */
235 .byte 0x0 /* segment base 24..32 */
237 kerneldata: /* offset = 0x10 */
239 .word 0xffff /* segment limit 0..15 */
240 .word 0x0000 /* segment base 0..15 */
241 .byte 0x0 /* segment base 16..23; set for 0k */
242 .byte 0x93 /* flags; Type */
243 .byte 0xcf /* flags; Limit */
244 .byte 0x0 /* segment base 24..32 */
246 bootcode: /* offset = 0x18 */
248 .word 0xffff /* segment limit 0..15 */
249 bootCodeSeg: /* this will be modified by mpInstallTramp() */
250 .word 0x0000 /* segment base 0..15 */
251 .byte 0x00 /* segment base 16...23; set for 0x000xx000 */
252 .byte 0x9e /* flags; Type */
253 .byte 0xcf /* flags; Limit */
254 .byte 0x0 /*segment base 24..32 */
256 bootdata: /* offset = 0x20 */
259 bootDataSeg: /* this will be modified by mpInstallTramp() */
260 .word 0x0000 /* segment base 0..15 */
261 .byte 0x00 /* segment base 16...23; set for 0x000xx000 */
267 * GDT pointer for the lgdt call
274 mp_gdtbase: /* this will be modified by mpInstallTramp() */
277 .space 0x100 /* space for boot_stk - 1st temporary stack */
283 .long BOOTMP2 - BOOTMP1