/* * (C) Copyright 2002 * Daniel Engstr�m, 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