diff options
Diffstat (limited to 'lib_i386/bios.S')
| -rw-r--r-- | lib_i386/bios.S | 135 |
1 files changed, 78 insertions, 57 deletions
diff --git a/lib_i386/bios.S b/lib_i386/bios.S index 2f5ea8c..ce6e94c 100644 --- a/lib_i386/bios.S +++ b/lib_i386/bios.S @@ -30,6 +30,8 @@ *---------------------------------------------------------------------- */ +#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 @@ -40,29 +42,13 @@ * a general purpose replacement for a real BIOS !! */ -#define OFFS_ES 0 -#define OFFS_GS 2 -#define OFFS_DS 4 -#define OFFS_DI 6 -#define OFFS_SI 8 -#define OFFS_BP 10 -#define OFFS_SP 12 -#define OFFS_BX 14 -#define OFFS_DX 16 -#define OFFS_CX 18 -#define OFFS_AX 20 -#define OFFS_VECTOR 22 -#define OFFS_IP 24 -#define OFFS_CS 26 -#define OFFS_FLAGS 28 - -#define SEGMENT 0x40 -#define STACK 0x800 /* stack at 0x40:0x800 -> 0x800 */ .section .bios, "ax" .code16 .org 0 - + /* a call to f000:0 should warmboot */ + jmp realmode_reset + .globl rm_int00 rm_int00: pushw $0 @@ -202,30 +188,23 @@ rm_def_int: * stack. */ any_interrupt16: - pusha /* save general registers */ - pushw %ds /* save some segments */ - pushw %gs - pushw %es - pushw %ss /* save callers stack segment .. */ - popw %gs /* ... in gs */ - movw $SEGMENT,%ax /* setup my segments */ - movw %ax,%ds - movw %ax,%es - movw %ax,%ss - movw %sp,%bp - movw $STACK,%sp /* setup BIOS stackpointer */ + 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 */ @@ -234,6 +213,9 @@ Lint_10h: /* VGA BIOS services */ Lint_11h: call bios_11h jmp Lout +Lint_12h: + call bios_12h + jmp Lout Lint_13h: /* BIOS disk services */ call bios_13h jmp Lout @@ -243,6 +225,9 @@ Lint_15h: /* Misc. BIOS services */ Lint_16h: /* keyboard services */ call bios_16h jmp Lout +Lint_1ah: /* PCI bios */ + call bios_1ah + jmp Lout Lout: cmpw $0, %ax je Lhandeled @@ -256,16 +241,7 @@ Lout: * we shuls make int 0x10 and int 0x16 work as well)) */ Lhandeled: - - pushw %gs /* restore callers stack segment */ - popw %ss - movw %bp,%sp /* restore stackpointer */ - - popw %es /* restore segment selectors */ - popw %gs - popw %ds - - popa /* restore GP registers */ + RESTORE_CALLERS_STACK addw $2,%sp /* dump vector number */ iret /* return from interrupt */ @@ -309,7 +285,7 @@ gs movw $0x10, OFFS_BX(%bp) /* indicate CGA/MDA/HGA */ */ bios_11h: - movw bios_equipment, %ax +cs movw bios_equipment, %ax gs movw %ax, OFFS_AX(%bp) xorw %ax, %ax ret @@ -317,6 +293,30 @@ gs movw %ax, OFFS_AX(%bp) /* ************************************************************ + * 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 ************************************************************ */ @@ -372,27 +372,28 @@ gs movw %ax, OFFS_FLAGS(%bp) ret Lfunc_e801h: /* Get memory size for >64M Configurations */ - movw $ram_in_64kb_chunks, %ax - cmpw $256, %ax - ja Lmore_than_16mb - shlw $6, %ax /* multiply by 64 */ -gs movw %ax, OFFS_AX(%bp) /* return memory size in 1kb chunks in AX and CX */ +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) - xorw %ax, %ax -gs movw %ax, OFFS_BX(%bp) /* set BX and DX to 0*/ -gs movw %ax, OFFS_DX(%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 -Lmore_than_16mb: +e801_more_than_16mb: subw $0x100, %ax /* subtract 16MB */ -gs movw $0x3c00, OFFS_AX(%bp) /* return 0x3c00 (16MB-384k) in AX and CX */ +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 - 256 */ +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 @@ -402,11 +403,15 @@ gs movw %ax, OFFS_FLAGS(%bp) ret Lfunc_88h: - movw ram_in_64kb_chunks, %ax - subw $16, %ax +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 - -gs movw %ax, OFFS_AX(%bp) /* return number of kilobytes in 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 */ @@ -432,6 +437,22 @@ 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: |