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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
|
#include <cpu/x86/post_code.h>
.section ".text"
.code32
.globl _start
_start:
cli
lgdt %cs:gdtaddr
ljmp $0x10, $1f
1: movl $0x18, %eax
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
post_code(POST_ENTRY_C_START) /* post 13 */
/** clear stack */
cld
leal _stack, %edi
movl $_estack, %ecx
subl %edi, %ecx
shrl $2, %ecx /* it is 32 bit aligned, right? */
xorl %eax, %eax
rep
stosl
/** clear bss */
leal _bss, %edi
movl $_ebss, %ecx
subl %edi, %ecx
jz .Lnobss
shrl $2, %ecx /* it is 32 bit aligned, right? */
xorl %eax, %eax
rep
stosl
.Lnobss:
/* set new stack */
movl $_estack, %esp
/* Push the cpu index and struct cpu */
pushl $0
pushl $0
/* push the boot_complete flag */
pushl %ebp
/* Save the stack location */
movl %esp, %ebp
/* Initialize the Interrupt Descriptor table */
leal _idt, %edi
leal vec0, %ebx
movl $(0x10 << 16), %eax /* cs selector */
1: movw %bx, %ax
movl %ebx, %edx
movw $0x8E00, %dx /* Interrupt gate - dpl=0, present */
movl %eax, 0(%edi)
movl %edx, 4(%edi)
addl $6, %ebx
addl $8, %edi
cmpl $_idt_end, %edi
jne 1b
/* Load the Interrupt descriptor table */
lidt idtarg
/*
* Now we are finished. Memory is up, data is copied and
* bss is cleared. Now we call the main routine and
* let it do the rest.
*/
post_code(POST_PRE_HARDWAREMAIN) /* post fe */
/* Restore the stack location */
movl %ebp, %esp
/* The boot_complete flag has already been pushed */
call hardwaremain
/* NOTREACHED */
.Lhlt:
post_code(POST_DEAD_CODE) /* post ee */
hlt
jmp .Lhlt
vec0:
pushl $0 /* error code */
pushl $0 /* vector */
jmp int_hand
vec1:
pushl $0 /* error code */
pushl $1 /* vector */
jmp int_hand
vec2:
pushl $0 /* error code */
pushl $2 /* vector */
jmp int_hand
vec3:
pushl $0 /* error code */
pushl $3 /* vector */
jmp int_hand
vec4:
pushl $0 /* error code */
pushl $4 /* vector */
jmp int_hand
vec5:
pushl $0 /* error code */
pushl $5 /* vector */
jmp int_hand
vec6:
pushl $0 /* error code */
pushl $6 /* vector */
jmp int_hand
vec7:
pushl $0 /* error code */
pushl $7 /* vector */
jmp int_hand
vec8:
/* error code */
pushl $8 /* vector */
jmp int_hand
.word 0x9090
vec9:
pushl $0 /* error code */
pushl $9 /* vector */
jmp int_hand
vec10:
/* error code */
pushl $10 /* vector */
jmp int_hand
.word 0x9090
vec11:
/* error code */
pushl $11 /* vector */
jmp int_hand
.word 0x9090
vec12:
/* error code */
pushl $12 /* vector */
jmp int_hand
.word 0x9090
vec13:
/* error code */
pushl $13 /* vector */
jmp int_hand
.word 0x9090
vec14:
/* error code */
pushl $14 /* vector */
jmp int_hand
.word 0x9090
vec15:
pushl $0 /* error code */
pushl $15 /* vector */
jmp int_hand
vec16:
pushl $0 /* error code */
pushl $16 /* vector */
jmp int_hand
vec17:
/* error code */
pushl $17 /* vector */
jmp int_hand
.word 0x9090
vec18:
pushl $0 /* error code */
pushl $18 /* vector */
jmp int_hand
vec19:
pushl $0 /* error code */
pushl $19 /* vector */
jmp int_hand
int_hand:
/* At this point on the stack there is:
* 0(%esp) vector
* 4(%esp) error code
* 8(%esp) eip
* 12(%esp) cs
* 16(%esp) eflags
*/
pushl %edi
pushl %esi
pushl %ebp
/* Original stack pointer */
leal 32(%esp), %ebp
pushl %ebp
pushl %ebx
pushl %edx
pushl %ecx
pushl %eax
pushl %esp /* Pointer to structure on the stack */
call x86_exception
pop %eax /* Drop the pointer */
popl %eax
popl %ecx
popl %edx
popl %ebx
popl %ebp /* Ignore saved %esp value */
popl %ebp
popl %esi
popl %edi
addl $8, %esp /* pop of the vector and error code */
iret
#if CONFIG_GDB_STUB == 1
.globl gdb_stub_breakpoint
gdb_stub_breakpoint:
popl %eax /* Return address */
pushfl
pushl %cs
pushl %eax /* Return address */
pushl $0 /* No error code */
pushl $32 /* vector 32 is user defined */
jmp int_hand
#endif
.globl gdt, gdt_end, gdt_limit, idtarg
gdt_limit = gdt_end - gdt - 1 /* compute the table limit */
gdtaddr:
.word gdt_limit
.long gdt /* we know the offset */
.data
/* This is the gdt for GCC part of coreboot.
* It is different from the gdt in ROMCC/ASM part of coreboot
* which is defined in entry32.inc
*
* When the machine is initially started, we use a very simple
* gdt from rom (that in entry32.inc) which only contains those
* entries we need for protected mode.
*
* When we're executing code from RAM, we want to do more complex
* stuff, like initializing PCI option roms in real mode, or doing
* a resume from a suspend to ram.
*/
gdt:
/* selgdt 0, unused */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x00, 0x00, 0x00
/* selgdt 8, unused */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x00, 0x00, 0x00
/* selgdt 0x10, flat code segment */
.word 0xffff, 0x0000
.byte 0x00, 0x9b, 0xcf, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */
/* selgdt 0x18, flat data segment */
.word 0xffff, 0x0000
.byte 0x00, 0x93, 0xcf, 0x00
/* selgdt 0x20, unused */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x00, 0x00, 0x00
/* The next two entries are used for executing VGA option ROMs */
/* selgdt 0x28 16 bit 64k code at 0x00000000 */
.word 0xffff, 0x0000
.byte 0, 0x9a, 0, 0
/* selgdt 0x30 16 bit 64k data at 0x00000000 */
.word 0xffff, 0x0000
.byte 0, 0x92, 0, 0
/* The next two entries are used for ACPI S3 RESUME */
/* selgdt 0x38, flat data segment 16 bit */
.word 0x0000, 0x0000 /* dummy */
.byte 0x00, 0x93, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */
/* selgdt 0x40, flat code segment 16 bit */
.word 0xffff, 0x0000
.byte 0x00, 0x9b, 0x8f, 0x00 /* G=1 and 0x0f, So we get 4Gbytes for limit */
gdt_end:
idtarg:
.word _idt_end - _idt - 1 /* limit */
.long _idt
.word 0
_idt:
.fill 20, 8, 0 # idt is uninitialized
_idt_end:
.previous
.code32
|
