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-rw-r--r--lib_i386/bios.S135
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: