| /* |
| * (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 |
| */ |
| |
| /* |
| * Based on msbios.c from rolo 1.6: |
| *---------------------------------------------------------------------- |
| * (C) Copyright 2000 |
| * Sysgo Real-Time Solutions GmbH |
| * Klein-Winternheim, Germany |
| *---------------------------------------------------------------------- |
| */ |
| |
| #include "bios.h" |
| |
| /* |
| * During it's initialization phase, before switching to protected |
| * mode, the Linux Kernel makes a few BIOS calls. This won't work |
| * if the board does not have a BIOS. |
| * |
| * This is a very minimalisic BIOS that supplies just enough |
| * functionality to keep the Linux Kernel happy. It is NOT |
| * a general purpose replacement for a real BIOS !! |
| */ |
| |
| |
| .section .bios, "ax" |
| .code16 |
| .org 0 |
| /* a call to f000:0 should warmboot */ |
| jmp realmode_reset |
| |
| .globl rm_int00 |
| rm_int00: |
| pushw $0 |
| jmp any_interrupt16 |
| .globl rm_int01 |
| rm_int01: |
| pushw $1 |
| jmp any_interrupt16 |
| .globl rm_int02 |
| rm_int02: |
| pushw $2 |
| jmp any_interrupt16 |
| .globl rm_int03 |
| rm_int03: |
| pushw $3 |
| jmp any_interrupt16 |
| .globl rm_int04 |
| rm_int04: |
| pushw $4 |
| jmp any_interrupt16 |
| .globl rm_int05 |
| rm_int05: |
| pushw $5 |
| jmp any_interrupt16 |
| .globl rm_int06 |
| rm_int06: |
| pushw $6 |
| jmp any_interrupt16 |
| .globl rm_int07 |
| rm_int07: |
| pushw $7 |
| jmp any_interrupt16 |
| .globl rm_int08 |
| rm_int08: |
| pushw $8 |
| jmp any_interrupt16 |
| .globl rm_int09 |
| rm_int09: |
| pushw $9 |
| jmp any_interrupt16 |
| .globl rm_int0a |
| rm_int0a: |
| pushw $10 |
| jmp any_interrupt16 |
| .globl rm_int0b |
| rm_int0b: |
| pushw $11 |
| jmp any_interrupt16 |
| .globl rm_int0c |
| rm_int0c: |
| pushw $12 |
| jmp any_interrupt16 |
| .globl rm_int0d |
| rm_int0d: |
| pushw $13 |
| jmp any_interrupt16 |
| .globl rm_int0e |
| rm_int0e: |
| pushw $14 |
| jmp any_interrupt16 |
| .globl rm_int0f |
| rm_int0f: |
| pushw $15 |
| jmp any_interrupt16 |
| .globl rm_int10 |
| rm_int10: |
| pushw $16 |
| jmp any_interrupt16 |
| .globl rm_int11 |
| rm_int11: |
| pushw $17 |
| jmp any_interrupt16 |
| .globl rm_int12 |
| rm_int12: |
| pushw $18 |
| jmp any_interrupt16 |
| .globl rm_int13 |
| rm_int13: |
| pushw $19 |
| jmp any_interrupt16 |
| .globl rm_int14 |
| rm_int14: |
| pushw $20 |
| jmp any_interrupt16 |
| .globl rm_int15 |
| rm_int15: |
| pushw $21 |
| jmp any_interrupt16 |
| .globl rm_int16 |
| rm_int16: |
| pushw $22 |
| jmp any_interrupt16 |
| .globl rm_int17 |
| rm_int17: |
| pushw $23 |
| jmp any_interrupt16 |
| .globl rm_int18 |
| rm_int18: |
| pushw $24 |
| jmp any_interrupt16 |
| .globl rm_int19 |
| rm_int19: |
| pushw $25 |
| jmp any_interrupt16 |
| .globl rm_int1a |
| rm_int1a: |
| pushw $26 |
| jmp any_interrupt16 |
| .globl rm_int1b |
| rm_int1b: |
| pushw $27 |
| jmp any_interrupt16 |
| .globl rm_int1c |
| rm_int1c: |
| pushw $28 |
| jmp any_interrupt16 |
| .globl rm_int1d |
| rm_int1d: |
| pushw $29 |
| jmp any_interrupt16 |
| .globl rm_int1e |
| rm_int1e: |
| pushw $30 |
| jmp any_interrupt16 |
| .globl rm_int1f |
| rm_int1f: |
| pushw $31 |
| jmp any_interrupt16 |
| .globl rm_def_int |
| rm_def_int: |
| iret |
| |
| |
| /* |
| * All interrupt jumptable entries jump to here |
| * after pushing the interrupt vector number onto the |
| * stack. |
| */ |
| any_interrupt16: |
| MAKE_BIOS_STACK |
| |
| gs movw OFFS_VECTOR(%bp), %ax |
| cmpw $0x10, %ax |
| je Lint_10h |
| cmpw $0x11, %ax |
| je Lint_11h |
| cmpw $0x12, %ax |
| je Lint_12h |
| cmpw $0x13, %ax |
| je Lint_13h |
| cmpw $0x15, %ax |
| je Lint_15h |
| cmpw $0x16, %ax |
| je Lint_16h |
| cmpw $0x1a, %ax |
| je Lint_1ah |
| movw $0xffff, %ax |
| jmp Lout |
| Lint_10h: /* VGA BIOS services */ |
| call bios_10h |
| jmp Lout |
| Lint_11h: |
| call bios_11h |
| jmp Lout |
| Lint_12h: |
| call bios_12h |
| jmp Lout |
| Lint_13h: /* BIOS disk services */ |
| call bios_13h |
| jmp Lout |
| Lint_15h: /* Misc. BIOS services */ |
| call bios_15h |
| jmp Lout |
| Lint_16h: /* keyboard services */ |
| call bios_16h |
| jmp Lout |
| Lint_1ah: /* PCI bios */ |
| call bios_1ah |
| jmp Lout |
| Lout: |
| cmpw $0, %ax |
| je Lhandeled |
| |
| /* Insert code for unhandeled INTs here. |
| * |
| * ROLO prints a message to the console |
| * (we could do that but then we're in 16bit mode |
| * so we'll have to get back into 32bit mode |
| * to use the console I/O routines (if we do this |
| * we shuls make int 0x10 and int 0x16 work as well)) |
| */ |
| Lhandeled: |
| RESTORE_CALLERS_STACK |
| addw $2,%sp /* dump vector number */ |
| iret /* return from interrupt */ |
| |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 10h -- VGA services |
| ************************************************************ |
| */ |
| bios_10h: |
| gs movw OFFS_AX(%bp), %ax |
| shrw $8, %ax |
| cmpw $0x3, %ax |
| je Lcur_pos |
| cmpw $0xf, %ax |
| je Lvid_state |
| cmpw $0x12, %ax |
| je Lvid_cfg |
| movw $0xffff, %ax |
| ret |
| Lcur_pos: /* Read Cursor Position and Size */ |
| gs movw $0, OFFS_CX(%bp) |
| gs movw $0, OFFS_DX(%bp) |
| xorw %ax, %ax |
| ret |
| Lvid_state: /* Get Video State */ |
| gs movw $(80 << 8|0x03), OFFS_AX(%bp) /* 80 columns, 80x25, 16 colors */ |
| gs movw $0, OFFS_BX(%bp) |
| xorw %ax, %ax |
| ret |
| Lvid_cfg: /* Video Subsystem Configuration (EGA/VGA) */ |
| gs movw $0x10, OFFS_BX(%bp) /* indicate CGA/MDA/HGA */ |
| xorw %ax, %ax |
| ret |
| |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 11h -- Equipment determination |
| ************************************************************ |
| */ |
| |
| bios_11h: |
| cs movw bios_equipment, %ax |
| gs movw %ax, OFFS_AX(%bp) |
| xorw %ax, %ax |
| ret |
| |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 12h -- Get Memory Size |
| ************************************************************ |
| */ |
| bios_12h: |
| cs movw ram_in_64kb_chunks, %ax |
| cmpw $0xa, %ax |
| ja b12_more_than_640k |
| shlw $6, %ax |
| jmp b12_return |
| b12_more_than_640k: |
| movw $0x280, %ax |
| b12_return: |
| gs movw %ax, OFFS_AX(%bp) /* return number of kilobytes in ax */ |
| |
| gs movw OFFS_FLAGS(%bp), %ax |
| andw $0xfffe, %ax /* clear carry -- function succeeded */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| |
| xorw %ax, %ax |
| ret |
| |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 13h -- Disk services |
| ************************************************************ |
| */ |
| bios_13h: |
| gs movw OFFS_AX(%bp), %ax |
| shrw $8, %ax |
| cmpw $0x15, %ax |
| je Lfunc_15h |
| movw $0xffff, %ax |
| ret |
| Lfunc_15h: |
| gs movw OFFS_AX(%bp), %ax |
| andw $0xff, %ax /* return AH=0->drive not present */ |
| gs movw %ax, OFFS_AX(%bp) |
| xorw %ax, %ax |
| ret |
| |
| |
| /* |
| *********************************************************** |
| * BIOS interrupt 15h -- Miscellaneous services |
| *********************************************************** |
| */ |
| bios_15h: |
| gs movw OFFS_AX(%bp), %ax |
| shrw $8, %ax |
| cmpw $0xc0, %ax |
| je Lfunc_c0h |
| cmpw $0xe8, %ax |
| je Lfunc_e8h |
| cmpw $0x88, %ax |
| je Lfunc_88h |
| movw $0xffff, %ax |
| ret |
| |
| Lfunc_c0h: /* Return System Configuration Parameters (PS2 only) */ |
| gs movw OFFS_FLAGS(%bp), %ax |
| orw $1, %ax /* return carry -- function not supported */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| xorw %ax, %ax |
| ret |
| |
| Lfunc_e8h: |
| gs movw OFFS_AX(%bp), %ax |
| andw $0xff, %ax |
| cmpw $1, %ax |
| je Lfunc_e801h |
| gs movw OFFS_FLAGS(%bp), %ax |
| orw $1, %ax /* return carry -- function not supported */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| xorw %ax, %ax |
| ret |
| |
| Lfunc_e801h: /* Get memory size for >64M Configurations */ |
| cs movw ram_in_64kb_chunks, %ax |
| cmpw $0x100, %ax |
| ja e801_more_than_16mb |
| shlw $6, %ax /* multiply by 64 */ |
| subw $0x400, %ax /* 1st meg does not count */ |
| |
| gs movw %ax, OFFS_AX(%bp) /* return memory size between 1M and 16M in 1kb chunks in AX and CX */ |
| gs movw %ax, OFFS_CX(%bp) |
| gs movw $0, OFFS_BX(%bp) /* set BX and DX to 0*/ |
| gs movw $0, OFFS_DX(%bp) |
| gs movw OFFS_FLAGS(%bp), %ax |
| andw $0xfffe, %ax /* clear carry -- function succeeded */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| xorw %ax, %ax |
| ret |
| |
| e801_more_than_16mb: |
| subw $0x100, %ax /* subtract 16MB */ |
| |
| gs movw $0x3c00, OFFS_AX(%bp) /* return 0x3c00 (16MB-1MB) in AX and CX */ |
| gs movw $0x3c00, OFFS_CX(%bp) |
| gs movw %ax, OFFS_BX(%bp) /* set BX and DX to number of 64kb chunks above 16MB */ |
| gs movw %ax, OFFS_DX(%bp) |
| |
| gs movw OFFS_FLAGS(%bp), %ax |
| andw $0xfffe, %ax /* clear carry -- function succeeded */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| xorw %ax, %ax |
| ret |
| |
| Lfunc_88h: |
| cs movw ram_in_64kb_chunks, %ax |
| cmpw $0x100, %ax |
| jna b88_not_more_than16 |
| movw $0x100, %ax |
| b88_not_more_than16: |
| shlw $6, %ax |
| subw $0x400, %ax /* 1st meg does not count */ |
| |
| gs movw %ax, OFFS_AX(%bp) /* return number of kilobytes between 16MB and 16MB in ax */ |
| |
| gs movw OFFS_FLAGS(%bp), %ax |
| andw $0xfffe, %ax /* clear carry -- function succeeded */ |
| gs movw %ax, OFFS_FLAGS(%bp) |
| |
| xorw %ax, %ax |
| ret |
| |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 16h -- keyboard services |
| ************************************************************ |
| */ |
| bios_16h: |
| gs movw OFFS_AX(%bp), %ax |
| shrw $8, %ax |
| cmpw $0x03, %ax |
| je Lfunc_03h |
| movw $0xffff, %ax |
| ret |
| Lfunc_03h: |
| xorw %ax, %ax /* do nothing -- function not supported */ |
| ret |
| |
| /* |
| ************************************************************ |
| * BIOS interrupt 1ah -- PCI bios |
| ************************************************************ |
| */ |
| bios_1ah: |
| gs movw OFFS_AX(%bp), %ax |
| cmpb $0xb1, %ah |
| je Lfunc_b1h |
| movw $0xffff, %ax |
| ret |
| Lfunc_b1h: |
| call realmode_pci_bios |
| xorw %ax, %ax /* do nothing -- function not supported */ |
| ret |
| |
| |
| .globl ram_in_64kb_chunks |
| ram_in_64kb_chunks: |
| .word 0 |
| |
| .globl bios_equipment |
| bios_equipment: |
| .word 0 |
