bios_pci.S
9.61 KB
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
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se
*
* See file CREDITS for list of people who contributed to this
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* x86 realmode assembly implementation of a PCI BIOS
* for platforms that use one PCI hose and configuration
* access type 1. (The common case for low-end PC's)
*/
#include "bios.h"
#define PCI_BIOS_DEBUG
.section .bios, "ax"
.code16
.globl realmode_pci_bios_call_entry
realmode_pci_bios_call_entry:
MAKE_BIOS_STACK
call realmode_pci_bios
RESTORE_CALLERS_STACK
ret
.globl realmode_pci_bios
realmode_pci_bios:
gs movw OFFS_AX(%bp), %ax
cmpb $1, %al
je pci_bios_present
cmpb $2, %al
je pci_bios_find_device
cmpb $3, %al
je pci_bios_find_class
cmpb $6, %al
je pci_bios_generate_special_cycle
cmpb $8, %al
je pci_bios_read_cfg_byte
cmpb $9, %al
je pci_bios_read_cfg_word
cmpb $10, %al
je pci_bios_read_cfg_dword
cmpb $11, %al
je pci_bios_write_cfg_byte
cmpb $12, %al
je pci_bios_write_cfg_word
cmpb $13, %al
je pci_bios_write_cfg_dword
cmpb $14, %al
je pci_bios_get_irq_routing
cmpb $15, %al
je pci_bios_set_irq
jmp unknown_function
/*****************************************************************************/
pci_bios_present:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_present
#endif
movl $0x20494350, %eax
gs movl %eax, OFFS_EDX(%bp)
movb $0x01, %al
gs movb %al, OFFS_AL(%bp) /* We support cfg type 1 */
movw $0x0210, %ax /* version 2.10 */
gs movw %ax, OFFS_BX(%bp)
cs movb pci_last_bus, %al /* last bus number */
gs movb %al, OFFS_CL(%bp)
jmp clear_carry
/*****************************************************************************/
/* device 0-31, function 0-7 */
pci_bios_find_device:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_find_device
#endif
gs movw OFFS_CX(%bp), %di
shll $16, %edi
gs movw OFFS_DX(%bp), %di /* edi now holds device in upper 16
* bits and vendor in lower 16 bits */
gs movw OFFS_SI(%bp), %si
xorw %bx, %bx /* start at bus 0 dev 0 function 0 */
pfd_loop:
xorw %ax, %ax /* dword 0 is vendor/device */
call __pci_bios_select_register
movw $0xcfc, %dx
inl %dx, %eax
cmpl %edi, %eax /* our device ? */
je pfd_found_one
pfd_next_dev:
/* check for multi function devices */
movw %bx, %ax
andw $3, %ax
jnz pfd_function_not_zero
movw $0x000c, %ax
call __pci_bios_select_register
movw $0xcfe, %dx
inb %dx, %al
andb $0x80, %al
jz pfd_not_multi_function
pfd_function_not_zero:
incw %bx /* next function, overflows in to
* device number, then bus number */
jmp pfd_check_bus
pfd_not_multi_function:
andw $0xfff8, %bx /* remove function bits */
addw $0x0008, %bx /* next device, overflows in to bus number */
pfd_check_bus:
cs movb pci_last_bus, %ah
cmpb %ah, %bh
ja pfd_not_found
jmp pfd_loop
pfd_found_one:
decw %si
js pfd_done
jmp pfd_next_dev
pfd_done:
gs movw %bx, OFFS_BX(%bp)
jmp clear_carry
pfd_not_found:
movb $0x86, %ah /* device not found */
jmp set_carry
/*****************************************************************************/
pci_bios_find_class:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_find_class
#endif
gs movl OFFS_ECX(%bp), %edi
andl $0x00ffffff, %edi /* edi now holds class-code in lower 24 bits */
gs movw OFFS_SI(%bp), %si
xorw %bx, %bx /* start at bus 0 dev 0 function 0 */
pfc_loop:
movw $8, %ax /* dword 8 is class-code high 24bits */
call __pci_bios_select_register
movw $0xcfc, %dx
inl %dx, %eax
shrl $8, %eax
andl $0x00ffffff, %eax
cmpl %edi, %eax /* our device ? */
je pfc_found_one
pfc_next_dev:
/* check for multi function devices */
andw $3, %bx
jnz pfc_function_not_zero
movw $0x000c, %ax
call __pci_bios_select_register
movw $0xcfe, %dx
inb %dx, %al
andb $0x80, %al
jz pfc_not_multi_function
pfc_function_not_zero:
incw %bx /* next function, overflows in to
* device number, then bus number */
jmp pfc_check_bus
pfc_not_multi_function:
andw $0xfff8, %bx /* remove function bits */
addw $0x0008, %bx /* next device, overflows in to bus number */
pfc_check_bus:
cs movb pci_last_bus, %ah
cmpb %ah, %bh
ja pfc_not_found
jmp pfc_loop
pfc_found_one:
decw %si
js pfc_done
jmp pfc_next_dev
pfc_done:
gs movw %bx, OFFS_BX(%bp)
jmp clear_carry
pfc_not_found:
movb $0x86, %ah /* device not found */
jmp set_carry
/*****************************************************************************/
pci_bios_generate_special_cycle:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_generate_special_cycle
#endif
movb $0x81, %ah /* function not supported */
jmp set_carry
/*****************************************************************************/
pci_bios_read_cfg_byte:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_read_cfg_byte
#endif
call pci_bios_select_register
gs movw OFFS_DI(%bp), %dx
andw $3, %dx
addw $0xcfc, %dx
inb %dx, %al
gs movb %al, OFFS_CL(%bp)
jmp clear_carry
/*****************************************************************************/
pci_bios_read_cfg_word:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_read_cfg_word
#endif
call pci_bios_select_register
gs movw OFFS_DI(%bp), %dx
andw $2, %dx
addw $0xcfc, %dx
inw %dx, %ax
gs movw %ax, OFFS_CX(%bp)
jmp clear_carry
/*****************************************************************************/
pci_bios_read_cfg_dword:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_read_cfg_dword
#endif
call pci_bios_select_register
movw $0xcfc, %dx
inl %dx, %eax
gs movl %eax, OFFS_ECX(%bp)
jmp clear_carry
/*****************************************************************************/
pci_bios_write_cfg_byte:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_write_cfg_byte
#endif
call pci_bios_select_register
gs movw OFFS_DI(%bp), %dx
gs movb OFFS_CL(%bp), %al
andw $3, %dx
addw $0xcfc, %dx
outb %al, %dx
jmp clear_carry
/*****************************************************************************/
pci_bios_write_cfg_word:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_write_cfg_word
#endif
call pci_bios_select_register
gs movw OFFS_DI(%bp), %dx
gs movw OFFS_CX(%bp), %ax
andw $2, %dx
addw $0xcfc, %dx
outw %ax, %dx
jmp clear_carry
/*****************************************************************************/
pci_bios_write_cfg_dword:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_write_cfg_dword
#endif
call pci_bios_select_register
gs movl OFFS_ECX(%bp), %eax
movw $0xcfc, %dx
outl %eax, %dx
jmp clear_carry
/*****************************************************************************/
pci_bios_get_irq_routing:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_get_irq_routing
#endif
movb $0x81, %ah /* function not supported */
jmp set_carry
/*****************************************************************************/
pci_bios_set_irq:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_set_irq
#endif
movb $0x81, %ah /* function not supported */
jmp set_carry
/*****************************************************************************/
unknown_function:
#ifdef PCI_BIOS_DEBUG
cs incl num_pci_bios_unknown_function
#endif
movb $0x81, %ah /* function not supported */
jmp set_carry
/*****************************************************************************/
pci_bios_select_register:
gs movw OFFS_BX(%bp), %bx
gs movw OFFS_DI(%bp), %ax
/* destroys eax, dx */
__pci_bios_select_register: /* BX holds device id, AX holds register index */
pushl %ebx
andl $0xfc, %eax
andl $0xffff, %ebx
shll $8, %ebx
orl %ebx, %eax
orl $0x80000000, %eax
movw $0xcf8, %dx
outl %eax, %dx
popl %ebx
ret
clear_carry:
gs movw OFFS_FLAGS(%bp), %ax
andw $0xfffe, %ax /* clear carry -- function succeeded */
gs movw %ax, OFFS_FLAGS(%bp)
xorw %ax, %ax
gs movb %ah, OFFS_AH(%bp)
ret
set_carry:
gs movb %ah, OFFS_AH(%bp)
gs movw OFFS_FLAGS(%bp), %ax
orw $1, %ax /* return carry -- function not supported */
gs movw %ax, OFFS_FLAGS(%bp)
movw $-1, %ax
ret
/*****************************************************************************/
.globl pci_last_bus
pci_last_bus:
.byte 0
#ifdef PCI_BIOS_DEBUG
.globl num_pci_bios_present
num_pci_bios_present:
.long 0
.globl num_pci_bios_find_device
num_pci_bios_find_device:
.long 0
.globl num_pci_bios_find_class
num_pci_bios_find_class:
.long 0
.globl num_pci_bios_generate_special_cycle
num_pci_bios_generate_special_cycle:
.long 0
.globl num_pci_bios_read_cfg_byte
num_pci_bios_read_cfg_byte:
.long 0
.globl num_pci_bios_read_cfg_word
num_pci_bios_read_cfg_word:
.long 0
.globl num_pci_bios_read_cfg_dword
num_pci_bios_read_cfg_dword:
.long 0
.globl num_pci_bios_write_cfg_byte
num_pci_bios_write_cfg_byte:
.long 0
.globl num_pci_bios_write_cfg_word
num_pci_bios_write_cfg_word:
.long 0
.globl num_pci_bios_write_cfg_dword
num_pci_bios_write_cfg_dword:
.long 0
.globl num_pci_bios_get_irq_routing
num_pci_bios_get_irq_routing:
.long 0
.globl num_pci_bios_set_irq
num_pci_bios_set_irq:
.long 0
.globl num_pci_bios_unknown_function
num_pci_bios_unknown_function:
.long 0
#endif