1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/*
* This file is part of the coreboot project.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <cpu/x86/mtrr.h>
#include <cpu/x86/cache.h>
#include <cpu/x86/post_code.h>
#define CACHE_AS_RAM_SIZE CONFIG_DCACHE_RAM_SIZE
#define CACHE_AS_RAM_BASE CONFIG_DCACHE_RAM_BASE
#if ((CONFIG_C_ENV_BOOTBLOCK_SIZE & (CONFIG_C_ENV_BOOTBLOCK_SIZE - 1)) != 0)
#error "CONFIG_C_ENV_BOOTBLOCK_SIZE must be a power of 2!"
#endif
#define XIP_ROM_SIZE CONFIG_C_ENV_BOOTBLOCK_SIZE
.global bootblock_pre_c_entry
.code32
_cache_as_ram_setup:
bootblock_pre_c_entry:
cache_as_ram:
post_code(0x20)
/* Clear/disable fixed MTRRs */
mov $fixed_mtrr_list_size, %ebx
xor %eax, %eax
xor %edx, %edx
clear_fixed_mtrr:
add $-2, %ebx
movzwl fixed_mtrr_list(%ebx), %ecx
wrmsr
jnz clear_fixed_mtrr
/* Figure out how many MTRRs we have, and clear them out */
mov $MTRR_CAP_MSR, %ecx
rdmsr
movzb %al, %ebx /* Number of variable MTRRs */
mov $MTRR_PHYS_BASE(0), %ecx
xor %eax, %eax
xor %edx, %edx
clear_var_mtrr:
wrmsr
inc %ecx
wrmsr
inc %ecx
dec %ebx
jnz clear_var_mtrr
post_code(0x21)
/* Configure the default memory type to uncacheable. */
movl $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
andl $(~0x00000cff), %eax
wrmsr
post_code(0x22)
/* Determine CPU_ADDR_BITS and load PHYSMASK high word to %edx. */
movl $1, %eax
cpuid
andl $(1 << 6 | 1 << 17), %edx /* PAE or PSE36 */
jz addrsize_set_high
movl $0x0f, %edx
/* Preload high word of address mask (in %edx) for Variable
MTRRs 0 and 1. */
addrsize_set_high:
xorl %eax, %eax
movl $MTRR_PHYS_MASK(0), %ecx
wrmsr
movl $MTRR_PHYS_MASK(1), %ecx
wrmsr
post_code(0x2a)
/* Set Cache-as-RAM base address. */
movl $(MTRR_PHYS_BASE(0)), %ecx
movl $(CACHE_AS_RAM_BASE | MTRR_TYPE_WRBACK), %eax
xorl %edx, %edx
wrmsr
/* Set Cache-as-RAM mask. */
movl $(MTRR_PHYS_MASK(0)), %ecx
rdmsr
movl $(~(CACHE_AS_RAM_SIZE - 1) | MTRR_PHYS_MASK_VALID), %eax
wrmsr
post_code(0x2b)
/* Enable MTRR. */
movl $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
orl $MTRR_DEF_TYPE_EN, %eax
wrmsr
post_code(0x2c)
/* Enable cache (CR0.CD = 0, CR0.NW = 0). */
movl %cr0, %eax
andl $(~(CR0_CacheDisable | CR0_NoWriteThrough)), %eax
invd
movl %eax, %cr0
/* Read then clear the CAR region. This will also fill up the cache.
* IMPORTANT: The read is mandatory.
*/
movl $CACHE_AS_RAM_BASE, %esi
movl %esi, %edi
cld
movl $(CACHE_AS_RAM_SIZE >> 2), %ecx
rep lodsl
movl $(CACHE_AS_RAM_SIZE >> 2), %ecx
xorl %eax, %eax
rep stosl
post_code(0x2d)
/* Enable Cache-as-RAM mode by disabling cache. */
movl %cr0, %eax
orl $CR0_CacheDisable, %eax
movl %eax, %cr0
/* Enable cache for our code in Flash because we do XIP here */
movl $MTRR_PHYS_BASE(1), %ecx
xorl %edx, %edx
/*
* IMPORTANT: The following calculation _must_ be done at runtime. See
* https://mail.coreboot.org/pipermail/coreboot/2010-October/060922.html
*/
movl $_program, %eax
andl $(~(XIP_ROM_SIZE - 1)), %eax
orl $MTRR_TYPE_WRPROT, %eax
wrmsr
movl $MTRR_PHYS_MASK(1), %ecx
rdmsr
movl $(~(XIP_ROM_SIZE - 1) | MTRR_PHYS_MASK_VALID), %eax
wrmsr
post_code(0x2e)
/* Enable cache. */
movl %cr0, %eax
andl $(~(CR0_CacheDisable | CR0_NoWriteThrough)), %eax
movl %eax, %cr0
/* Setup the stack. */
mov $_ecar_stack, %esp
/* Need to align stack to 16 bytes at call instruction. Account for
the pushes below. */
andl $0xfffffff0, %esp
subl $4, %esp
/* push TSC and BIST to stack */
movd %mm0, %eax
pushl %eax /* BIST */
movd %mm2, %eax
pushl %eax /* tsc[63:32] */
movd %mm1, %eax
pushl %eax /* tsc[31:0] */
before_c_entry:
post_code(0x29)
call bootblock_c_entry_bist
/* Should never see this postcode */
post_code(POST_DEAD_CODE)
.Lhlt:
hlt
jmp .Lhlt
fixed_mtrr_list:
.word MTRR_FIX_64K_00000
.word MTRR_FIX_16K_80000
.word MTRR_FIX_16K_A0000
.word MTRR_FIX_4K_C0000
.word MTRR_FIX_4K_C8000
.word MTRR_FIX_4K_D0000
.word MTRR_FIX_4K_D8000
.word MTRR_FIX_4K_E0000
.word MTRR_FIX_4K_E8000
.word MTRR_FIX_4K_F0000
.word MTRR_FIX_4K_F8000
fixed_mtrr_list_size = . - fixed_mtrr_list
_cache_as_ram_setup_end:
|