summaryrefslogtreecommitdiffstats
path: root/lib_i386/bios_pci.S
blob: 67fd00b83433ae0bd4632908821491319fb1799f (plain)
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
OpenPOWER on IntegriCloud