diff options
Diffstat (limited to 'arch/i386/lib/bios.S')
| -rw-r--r-- | arch/i386/lib/bios.S | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/arch/i386/lib/bios.S b/arch/i386/lib/bios.S new file mode 100644 index 0000000..48f1b81 --- /dev/null +++ b/arch/i386/lib/bios.S @@ -0,0 +1,532 @@ +/* + * (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 +.hidden rm_int00 +.type rm_int00, @function +rm_int00: + pushw $0 + jmp any_interrupt16 +.globl rm_int01 +.hidden rm_int01 +.type rm_int01, @function +rm_int01: + pushw $1 + jmp any_interrupt16 +.globl rm_int02 +.hidden rm_int02 +.type rm_int02, @function +rm_int02: + pushw $2 + jmp any_interrupt16 +.globl rm_int03 +.hidden rm_int03 +.type rm_int03, @function +rm_int03: + pushw $3 + jmp any_interrupt16 +.globl rm_int04 +.hidden rm_int04 +.type rm_int04, @function +rm_int04: + pushw $4 + jmp any_interrupt16 +.globl rm_int05 +.hidden rm_int05 +.type rm_int05, @function +rm_int05: + pushw $5 + jmp any_interrupt16 +.globl rm_int06 +.hidden rm_int06 +.type rm_int06, @function +rm_int06: + pushw $6 + jmp any_interrupt16 +.globl rm_int07 +.hidden rm_int07 +.type rm_int07, @function +rm_int07: + pushw $7 + jmp any_interrupt16 +.globl rm_int08 +.hidden rm_int08 +.type rm_int08, @function +rm_int08: + pushw $8 + jmp any_interrupt16 +.globl rm_int09 +.hidden rm_int09 +.type rm_int09, @function +rm_int09: + pushw $9 + jmp any_interrupt16 +.globl rm_int0a +.hidden rm_int0a +.type rm_int0a, @function +rm_int0a: + pushw $10 + jmp any_interrupt16 +.globl rm_int0b +.hidden rm_int0b +.type rm_int0b, @function +rm_int0b: + pushw $11 + jmp any_interrupt16 +.globl rm_int0c +.hidden rm_int0c +.type rm_int0c, @function +rm_int0c: + pushw $12 + jmp any_interrupt16 +.globl rm_int0d +.hidden rm_int0d +.type rm_int0d, @function +rm_int0d: + pushw $13 + jmp any_interrupt16 +.globl rm_int0e +.hidden rm_int0e +.type rm_int0e, @function +rm_int0e: + pushw $14 + jmp any_interrupt16 +.globl rm_int0f +.hidden rm_int0f +.type rm_int0f, @function +rm_int0f: + pushw $15 + jmp any_interrupt16 +.globl rm_int10 +.hidden rm_int10 +.type rm_int10, @function +rm_int10: + pushw $16 + jmp any_interrupt16 +.globl rm_int11 +.hidden rm_int11 +.type rm_int11, @function +rm_int11: + pushw $17 + jmp any_interrupt16 +.globl rm_int12 +.hidden rm_int12 +.type rm_int12, @function +rm_int12: + pushw $18 + jmp any_interrupt16 +.globl rm_int13 +.hidden rm_int13 +.type rm_int13, @function +rm_int13: + pushw $19 + jmp any_interrupt16 +.globl rm_int14 +.hidden rm_int14 +.type rm_int14, @function +rm_int14: + pushw $20 + jmp any_interrupt16 +.globl rm_int15 +.hidden rm_int15 +.type rm_int15, @function +rm_int15: + pushw $21 + jmp any_interrupt16 +.globl rm_int16 +.hidden rm_int16 +.type rm_int16, @function +rm_int16: + pushw $22 + jmp any_interrupt16 +.globl rm_int17 +.hidden rm_int17 +.type rm_int17, @function +rm_int17: + pushw $23 + jmp any_interrupt16 +.globl rm_int18 +.hidden rm_int18 +.type rm_int18, @function +rm_int18: + pushw $24 + jmp any_interrupt16 +.globl rm_int19 +.hidden rm_int19 +.type rm_int19, @function +rm_int19: + pushw $25 + jmp any_interrupt16 +.globl rm_int1a +.hidden rm_int1a +.type rm_int1a, @function +rm_int1a: + pushw $26 + jmp any_interrupt16 +.globl rm_int1b +.hidden rm_int1b +.type rm_int1b, @function +rm_int1b: + pushw $27 + jmp any_interrupt16 +.globl rm_int1c +.hidden rm_int1c +.type rm_int1c, @function +rm_int1c: + pushw $28 + jmp any_interrupt16 +.globl rm_int1d +.hidden rm_int1d +.type rm_int1d, @function +rm_int1d: + pushw $29 + jmp any_interrupt16 +.globl rm_int1e +.hidden rm_int1e +.type rm_int1e, @function +rm_int1e: + pushw $30 + jmp any_interrupt16 +.globl rm_int1f +.hidden rm_int1f +.type rm_int1f, @function +rm_int1f: + pushw $31 + jmp any_interrupt16 +.globl rm_def_int +.hidden rm_def_int +.type rm_def_int, @function +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 +.hidden ram_in_64kb_chunks +.type ram_in_64kb_chunks, @function +ram_in_64kb_chunks: + .word 0 + +.globl bios_equipment +.hidden bios_equipment +.type bios_equipment, @function +bios_equipment: + .word 0 |