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More changes for stupid VGA bioses.

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This commit is contained in:
Ronald G. Minnich 2002-03-29 04:32:20 +00:00
commit ac7042a2f3
3 changed files with 92 additions and 6 deletions
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85
src/arch/i386/lib/idt.c
View file

@ -1,25 +1,108 @@
#include <string.h>
#include <printk.h>
// we had hoped to avoid this.
// this is a stub IDT only. It's main purpose is to ignore calls
// to the BIOS.
// no longer. Dammit. We have to respond to these.
struct realidt {
unsigned short offset, cs;
};
// handler.
// There are some assumptions we can make here.
// First, the Top Of Stack (TOS) is located on the top of page zero.
// we can share this stack between real and protected mode.
// that simplifies a lot of things ...
// we'll just push all the registers on the stack as longwords,
// and pop to protected mode.
// second, since this only ever runs as part of linuxbios,
// we know all the segment register values -- so we don't save any.
void handler(void) {
__asm__ __volatile__ (
".code16\n"
"idthandle:\n"
" movb $0x55, %al\n"
" outb %al, $0x80\n"
" pushl %eax\n"
" pushl %ebx\n"
" pushl %ecx\n"
" pushl %edx\n"
" pushl %edi\n"
" pushl %esi\n"
"movl %cr0, %eax\n"
"andl $0x7FFAFFD1, %eax\n" /* PG,AM,WP,NE,TS,EM,MP = 0 */
"orl $0x60000001, %eax\n" /* CD, NW, PE = 1 */
"movl %eax, %cr0\n"
/* Now that we are in protected mode jump to a 32 bit code segment. */
"data32 ljmp $0x10, $biosprotect\n"
"biosprotect:\n"
".code32\n"
" movw $0x18, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
" mov %ax, %ss \n"
" call biosint \n"
// back to real mode ...
" ljmp $0x28, $__rms_16bit\n"
"__rms_16bit: \n"
".code16 \n" /* 16 bit code from here on... */
/* Load the segment registers w/ properly configured segment
* descriptors. They will retain these configurations (limits,
* writability, etc.) once protected mode is turned off. */
" mov $0x30, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
" mov %ax, %ss \n"
/* Turn off protection (bit 0 in CR0) */
" movl %cr0, %eax \n"
" andl $0xFFFFFFFE, %eax \n"
" movl %eax, %cr0 \n"
/* Now really going into real mode */
" ljmp $0, $__rms_real \n"
"__rms_real: \n"
/* Setup a stack */
" mov $0x0, %ax \n"
" mov %ax, %ss \n"
/* ebugging for RGM */
" mov $0x11, %al \n"
" outb %al, $0x80\n"
" xor %ax, %ax \n"
" mov %ax, %ds \n"
" mov %ax, %es \n"
" mov %ax, %fs \n"
" mov %ax, %gs \n"
" popl %eax\n"
" popl %ebx\n"
" popl %ecx\n"
" popl %edx\n"
" popl %edi\n"
" popl %esi\n"
" iret\n"
"end_idthandle:\n"
".code32\n"
);
}
int
biosint(unsigned long eax,
unsigned long ebx,
unsigned long ecx,
unsigned long edx,
unsigned long edi,
unsigned long esi) {
printk_debug("biosint: eax 0x%lx ebx 0x%lx ecx 0x%lx edx 0x%lx\n",
eax, ebx, ecx, edx);
printk_debug("biosint: edi 0x%lx esi 0x%lx\n", edi, esi);
}
void
setup_realmode_idt(void) {
extern unsigned char idthandle, end_idthandle;

7
src/arch/i386/lib/vgabios.c
View file

@ -102,10 +102,13 @@ static void real_mode_switch_call_vga(void)
" ljmp $0, $__rms_real \n"
"__rms_real: \n"
// put the stack at the end of page zero.
// that way we can easily share it between real and protected,
// since the 16-bit ESP at segment 0 will work for any case.
/* Setup a stack */
" mov $0x9000, %ax \n"
" mov $0x0, %ax \n"
" mov %ax, %ss \n"
" mov $0xAFFE, %ax \n"
" mov $0x1000, %ax \n"
" mov %ax, %sp \n"
/* ebugging for RGM */
" mov $0x11, %al \n"

6
src/mainboard/asus/cua/Config
View file

@ -14,9 +14,9 @@ southbridge acer/m1535
superio acer/m1535
mainboardinit cpu/p6/earlymtrr.inc
option ENABLE_FIXED_AND_VARIABLE_MTRRS
option FINAL_MAINBOARD_FIXUP
option HAVE_PIRQ_TABLE
option ENABLE_FIXED_AND_VARIABLE_MTRRS=1
option FINAL_MAINBOARD_FIXUP=1
option HAVE_PIRQ_TABLE=1
object mainboard.o
object irq_tables.o
keyboard pc80