lib_i386/bios_pci.S

   1 /*
   2  * (C) Copyright 2002
   3  * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 /*
  25  * x86 realmode assembly implementation of a PCI BIOS
  26  * for platforms that use one PCI hose and configuration
  27  * access type 1. (The common case for low-end PC's)
  28  */
  29
  30 #include "bios.h"
  31
  32 #define PCI_BIOS_DEBUG
  33
  34 .section .bios, "ax"
  35 .code16
  36 .globl realmode_pci_bios_call_entry
  37 .hidden realmode_pci_bios_call_entry
  38 .type realmode_pci_bios_call_entry, @function
  39 realmode_pci_bios_call_entry:
  40         MAKE_BIOS_STACK
  41         call realmode_pci_bios
  42         RESTORE_CALLERS_STACK
  43         ret
  44
  45
  46 .globl realmode_pci_bios
  47 realmode_pci_bios:
  48 gs      movw    OFFS_AX(%bp), %ax
  49         cmpb    $1, %al
  50         je      pci_bios_present
  51         cmpb    $2, %al
  52         je      pci_bios_find_device
  53         cmpb    $3, %al
  54         je      pci_bios_find_class
  55         cmpb    $6, %al
  56         je      pci_bios_generate_special_cycle
  57         cmpb    $8, %al
  58         je      pci_bios_read_cfg_byte
  59         cmpb    $9, %al
  60         je      pci_bios_read_cfg_word
  61         cmpb    $10, %al
  62         je      pci_bios_read_cfg_dword
  63         cmpb    $11, %al
  64         je      pci_bios_write_cfg_byte
  65         cmpb    $12, %al
  66         je      pci_bios_write_cfg_word
  67         cmpb    $13, %al
  68         je      pci_bios_write_cfg_dword
  69         cmpb    $14, %al
  70         je      pci_bios_get_irq_routing
  71         cmpb    $15, %al
  72         je      pci_bios_set_irq
  73         jmp     unknown_function
  74
  75 /*****************************************************************************/
  76
  77 pci_bios_present:
  78 #ifdef PCI_BIOS_DEBUG
  79 cs      incl    num_pci_bios_present
  80 #endif
  81         movl    $0x20494350, %eax
  82 gs      movl    %eax, OFFS_EDX(%bp)
  83         movb    $0x01, %al
  84 gs      movb    %al, OFFS_AL(%bp)       /* We support cfg type 1 */
  85         movw    $0x0210, %ax            /* version 2.10 */
  86 gs      movw    %ax, OFFS_BX(%bp)
  87 cs      movb    pci_last_bus, %al       /* last bus number */
  88 gs      movb    %al, OFFS_CL(%bp)
  89         jmp     clear_carry
  90
  91 /*****************************************************************************/
  92
  93 /* device 0-31, function 0-7 */
  94 pci_bios_find_device:
  95 #ifdef PCI_BIOS_DEBUG
  96 cs      incl    num_pci_bios_find_device
  97 #endif
  98 gs      movw    OFFS_CX(%bp), %di
  99         shll    $16, %edi
 100 gs      movw    OFFS_DX(%bp), %di       /* edi now holds device in upper 16
 101                                          * bits and vendor in lower 16 bits */
 102 gs      movw    OFFS_SI(%bp), %si
 103         xorw    %bx, %bx                /* start at bus 0 dev 0 function 0 */
 104 pfd_loop:
 105         xorw    %ax, %ax                /* dword 0 is vendor/device */
 106         call    __pci_bios_select_register
 107         movw    $0xcfc, %dx
 108         inl     %dx, %eax
 109         cmpl    %edi, %eax              /* our device ? */
 110         je      pfd_found_one
 111 pfd_next_dev:
 112         /* check for multi function devices */
 113         movw    %bx, %ax
 114         andw    $3, %ax
 115         jnz     pfd_function_not_zero
 116         movw    $0x000c, %ax
 117         call    __pci_bios_select_register
 118         movw    $0xcfe, %dx
 119         inb     %dx, %al
 120         andb    $0x80, %al
 121         jz      pfd_not_multi_function
 122 pfd_function_not_zero:
 123         incw    %bx                     /* next function, overflows in to
 124                                          * device number, then bus number */
 125         jmp     pfd_check_bus
 126
 127 pfd_not_multi_function:
 128         andw    $0xfff8, %bx            /* remove function bits */
 129         addw    $0x0008, %bx            /* next device, overflows in to bus number */
 130 pfd_check_bus:
 131 cs      movb    pci_last_bus, %ah
 132         cmpb    %ah, %bh
 133         ja      pfd_not_found
 134         jmp     pfd_loop
 135 pfd_found_one:
 136         decw    %si
 137         js      pfd_done
 138         jmp     pfd_next_dev
 139
 140 pfd_done:
 141 gs      movw    %bx, OFFS_BX(%bp)
 142         jmp     clear_carry
 143
 144 pfd_not_found:
 145         movb    $0x86, %ah              /* device not found */
 146         jmp     set_carry
 147
 148 /*****************************************************************************/
 149
 150 pci_bios_find_class:
 151 #ifdef PCI_BIOS_DEBUG
 152 cs      incl    num_pci_bios_find_class
 153 #endif
 154 gs      movl    OFFS_ECX(%bp), %edi
 155         andl    $0x00ffffff, %edi       /* edi now holds class-code in lower 24 bits */
 156 gs      movw    OFFS_SI(%bp), %si
 157         xorw    %bx, %bx                /* start at bus 0 dev 0 function 0 */
 158 pfc_loop:
 159         movw    $8, %ax                 /* dword 8 is class-code high 24bits */
 160         call    __pci_bios_select_register
 161         movw    $0xcfc, %dx
 162         inl     %dx, %eax
 163         shrl    $8, %eax
 164         andl    $0x00ffffff, %eax
 165         cmpl    %edi, %eax              /* our device ? */
 166         je      pfc_found_one
 167 pfc_next_dev:
 168         /* check for multi function devices */
 169         andw    $3, %bx
 170         jnz     pfc_function_not_zero
 171         movw    $0x000c, %ax
 172         call    __pci_bios_select_register
 173         movw    $0xcfe, %dx
 174         inb     %dx, %al
 175         andb    $0x80, %al
 176         jz      pfc_not_multi_function
 177 pfc_function_not_zero:
 178         incw    %bx                     /* next function, overflows in to
 179                                          * device number, then bus number */
 180         jmp     pfc_check_bus
 181
 182 pfc_not_multi_function:
 183         andw    $0xfff8, %bx            /* remove function bits */
 184         addw    $0x0008, %bx            /* next device, overflows in to bus number */
 185 pfc_check_bus:
 186 cs      movb    pci_last_bus, %ah
 187         cmpb    %ah, %bh
 188         ja      pfc_not_found
 189         jmp     pfc_loop
 190 pfc_found_one:
 191         decw    %si
 192         js      pfc_done
 193         jmp     pfc_next_dev
 194
 195 pfc_done:
 196 gs      movw    %bx, OFFS_BX(%bp)
 197         jmp     clear_carry
 198
 199 pfc_not_found:
 200         movb    $0x86, %ah              /* device not found */
 201         jmp     set_carry
 202
 203 /*****************************************************************************/
 204
 205 pci_bios_generate_special_cycle:
 206 #ifdef PCI_BIOS_DEBUG
 207 cs      incl    num_pci_bios_generate_special_cycle
 208 #endif
 209         movb    $0x81, %ah              /* function not supported */
 210         jmp     set_carry
 211
 212 /*****************************************************************************/
 213
 214 pci_bios_read_cfg_byte:
 215 #ifdef PCI_BIOS_DEBUG
 216 cs      incl    num_pci_bios_read_cfg_byte
 217 #endif
 218         call    pci_bios_select_register
 219 gs      movw    OFFS_DI(%bp), %dx
 220         andw    $3, %dx
 221         addw    $0xcfc, %dx
 222         inb     %dx, %al
 223 gs      movb    %al, OFFS_CL(%bp)
 224         jmp     clear_carry
 225
 226 /*****************************************************************************/
 227
 228 pci_bios_read_cfg_word:
 229 #ifdef PCI_BIOS_DEBUG
 230 cs      incl    num_pci_bios_read_cfg_word
 231 #endif
 232         call    pci_bios_select_register
 233 gs      movw    OFFS_DI(%bp), %dx
 234         andw    $2, %dx
 235         addw    $0xcfc, %dx
 236         inw     %dx, %ax
 237 gs      movw    %ax, OFFS_CX(%bp)
 238         jmp     clear_carry
 239
 240
 241 /*****************************************************************************/
 242
 243 pci_bios_read_cfg_dword:
 244 #ifdef PCI_BIOS_DEBUG
 245 cs      incl    num_pci_bios_read_cfg_dword
 246 #endif
 247         call    pci_bios_select_register
 248         movw    $0xcfc, %dx
 249         inl     %dx, %eax
 250 gs      movl    %eax, OFFS_ECX(%bp)
 251         jmp     clear_carry
 252
 253 /*****************************************************************************/
 254
 255 pci_bios_write_cfg_byte:
 256 #ifdef PCI_BIOS_DEBUG
 257 cs      incl    num_pci_bios_write_cfg_byte
 258 #endif
 259         call    pci_bios_select_register
 260 gs      movw    OFFS_DI(%bp), %dx
 261 gs      movb    OFFS_CL(%bp), %al
 262         andw    $3, %dx
 263         addw    $0xcfc, %dx
 264         outb    %al, %dx
 265         jmp     clear_carry
 266
 267 /*****************************************************************************/
 268
 269 pci_bios_write_cfg_word:
 270 #ifdef PCI_BIOS_DEBUG
 271 cs      incl    num_pci_bios_write_cfg_word
 272 #endif
 273         call    pci_bios_select_register
 274 gs      movw    OFFS_DI(%bp), %dx
 275 gs      movw    OFFS_CX(%bp), %ax
 276         andw    $2, %dx
 277         addw    $0xcfc, %dx
 278         outw    %ax, %dx
 279         jmp     clear_carry
 280
 281 /*****************************************************************************/
 282
 283 pci_bios_write_cfg_dword:
 284 #ifdef PCI_BIOS_DEBUG
 285 cs      incl    num_pci_bios_write_cfg_dword
 286 #endif
 287         call    pci_bios_select_register
 288 gs      movl    OFFS_ECX(%bp), %eax
 289         movw    $0xcfc, %dx
 290         outl    %eax, %dx
 291         jmp     clear_carry
 292
 293 /*****************************************************************************/
 294
 295 pci_bios_get_irq_routing:
 296 #ifdef PCI_BIOS_DEBUG
 297 cs      incl    num_pci_bios_get_irq_routing
 298 #endif
 299         movb    $0x81, %ah              /* function not supported */
 300         jmp     set_carry
 301
 302 /*****************************************************************************/
 303
 304 pci_bios_set_irq:
 305 #ifdef PCI_BIOS_DEBUG
 306 cs      incl    num_pci_bios_set_irq
 307 #endif
 308         movb    $0x81, %ah              /* function not supported */
 309         jmp     set_carry
 310
 311 /*****************************************************************************/
 312
 313 unknown_function:
 314 #ifdef PCI_BIOS_DEBUG
 315 cs      incl    num_pci_bios_unknown_function
 316 #endif
 317         movb    $0x81, %ah              /* function not supported */
 318         jmp     set_carry
 319
 320 /*****************************************************************************/
 321
 322 pci_bios_select_register:
 323 gs      movw    OFFS_BX(%bp), %bx
 324 gs      movw    OFFS_DI(%bp), %ax
 325 /* destroys eax, dx */
 326 __pci_bios_select_register:               /* BX holds device id, AX holds register index */
 327         pushl   %ebx
 328         andl    $0xfc, %eax
 329         andl    $0xffff, %ebx
 330         shll    $8, %ebx
 331         orl     %ebx, %eax
 332         orl     $0x80000000, %eax
 333         movw    $0xcf8, %dx
 334         outl    %eax, %dx
 335         popl    %ebx
 336         ret
 337
 338
 339 clear_carry:
 340 gs      movw    OFFS_FLAGS(%bp), %ax
 341         andw    $0xfffe, %ax                    /* clear carry -- function succeeded */
 342 gs      movw    %ax, OFFS_FLAGS(%bp)
 343         xorw    %ax, %ax
 344 gs      movb    %ah, OFFS_AH(%bp)
 345         ret
 346
 347 set_carry:
 348 gs      movb    %ah, OFFS_AH(%bp)
 349 gs      movw    OFFS_FLAGS(%bp), %ax
 350         orw     $1, %ax                         /* return carry -- function not supported */
 351 gs      movw    %ax, OFFS_FLAGS(%bp)
 352         movw    $-1, %ax
 353         ret
 354
 355 /*****************************************************************************/
 356
 357 .globl pci_last_bus
 358 pci_last_bus:
 359         .byte   0
 360
 361 #ifdef PCI_BIOS_DEBUG
 362 .globl num_pci_bios_present
 363 num_pci_bios_present:
 364         .long   0
 365
 366 .globl num_pci_bios_find_device
 367 num_pci_bios_find_device:
 368         .long   0
 369
 370 .globl num_pci_bios_find_class
 371 num_pci_bios_find_class:
 372         .long   0
 373
 374 .globl num_pci_bios_generate_special_cycle
 375 num_pci_bios_generate_special_cycle:
 376         .long 0
 377
 378 .globl num_pci_bios_read_cfg_byte
 379 num_pci_bios_read_cfg_byte:
 380         .long   0
 381
 382 .globl num_pci_bios_read_cfg_word
 383 num_pci_bios_read_cfg_word:
 384         .long   0
 385
 386 .globl num_pci_bios_read_cfg_dword
 387 num_pci_bios_read_cfg_dword:
 388         .long   0
 389
 390 .globl num_pci_bios_write_cfg_byte
 391 num_pci_bios_write_cfg_byte:
 392         .long   0
 393
 394 .globl num_pci_bios_write_cfg_word
 395 num_pci_bios_write_cfg_word:
 396         .long   0
 397
 398 .globl num_pci_bios_write_cfg_dword
 399 num_pci_bios_write_cfg_dword:
 400         .long   0
 401
 402 .globl num_pci_bios_get_irq_routing
 403 num_pci_bios_get_irq_routing:
 404         .long   0
 405
 406 .globl num_pci_bios_set_irq
 407 num_pci_bios_set_irq:
 408         .long   0
 409
 410 .globl num_pci_bios_unknown_function
 411 num_pci_bios_unknown_function:
 412         .long   0
 413 #endif