diff options
| -rw-r--r-- | src/pc80/vgabios.c | 179 |
1 files changed, 91 insertions, 88 deletions
diff --git a/src/pc80/vgabios.c b/src/pc80/vgabios.c index e381f91055..c83498e985 100644 --- a/src/pc80/vgabios.c +++ b/src/pc80/vgabios.c @@ -66,87 +66,88 @@ /* The address arguments to this function are PHYSICAL ADDRESSES */ static void real_mode_switch_call_vga(unsigned long devfn) { - __asm__ __volatile__ - ( - // paranoia -- does ecx get saved? not sure. This is - // the easiest safe thing to do. - "pushal\n" - /* save the stack */ - "mov %esp, __stack\n" - "jmp 1f\n" - "__stack: .long 0\n" - "1:\n" - /* get devfn into %ecx */ - "movl %esp, %ebp\n" - "movl 8(%ebp), %ecx\n" - /* This configures CS properly for 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" - - // 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 $0x0, %ax \n" - " mov %ax, %ss \n" - " movl $0x1000, %eax \n" - " movl %eax, %esp \n" - /* debugging for RGM */ - " mov $0x11, %al \n" - " outb %al, $0x80\n" - - /* Dump zeros in the other segregs */ - " xor %ax, %ax \n" - " mov %ax, %ds \n" - " mov %ax, %es \n" - " mov %ax, %fs \n" - " mov %ax, %gs \n" - " mov %cx, %ax \n" - " .byte 0x9a, 0x03, 0, 0, 0xc0 \n" - " movb $0x55, %al\noutb %al, $0x80\n" - /* if we got here, just about done. - * Need to get back to protected mode */ - "movl %cr0, %eax\n" - // "andl $0x7FFAFFD1, %eax\n" /* PG,AM,WP,NE,TS,EM,MP = 0 */ - // "orl $0x60000001, %eax\n" /* CD, NW, PE = 1 */ - "orl $0x0000001, %eax\n" /* PE = 1 */ - "movl %eax, %cr0\n" - /* Now that we are in protected mode jump to a 32 bit code segment. */ - "data32 ljmp $0x10, $vgarestart\n" - "vgarestart:\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" - ".globl vga_exit\n" - "vga_exit:\n" - " mov __stack, %esp\n" - " popal\n" - ); + __asm__ __volatile__ ( + // paranoia -- does ecx get saved? not sure. This is + // the easiest safe thing to do. + " pushal\n" + /* save the stack */ + " mov %esp, __stack\n" + " jmp 1f\n" + "__stack: .long 0\n" + "1:\n" + /* get devfn into %ecx */ + " movl %esp, %ebp\n" + " movl 8(%ebp), %ecx\n" + /* This configures CS properly for 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" + + // 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 $0x0, %ax \n" + " mov %ax, %ss \n" + " movl $0x1000, %eax \n" + " movl %eax, %esp \n" + /* debugging for RGM */ + " mov $0x11, %al \n" + " outb %al, $0x80\n" + + /* Dump zeros in the other segregs */ + " xor %ax, %ax \n" + " mov %ax, %ds \n" + " mov %ax, %es \n" + " mov %ax, %fs \n" + " mov %ax, %gs \n" + " mov %cx, %ax \n" + " .byte 0x9a, 0x03, 0, 0, 0xc0 \n" + " movb $0x55, %al\noutb %al, $0x80\n" + /* if we got here, just about done. + * Need to get back to protected mode */ + "movl %cr0, %eax\n" + // "andl $0x7FFAFFD1, %eax\n" /* PG,AM,WP,NE,TS,EM,MP = 0 */ + // "orl $0x60000001, %eax\n" /* CD, NW, PE = 1 */ + "orl $0x0000001, %eax\n" /* PE = 1 */ + "movl %eax, %cr0\n" + /* Now that we are in protected mode jump to a 32 bit code segment. */ + "data32 ljmp $0x10, $vgarestart\n" + "vgarestart:\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" + ".globl vga_exit\n" + "vga_exit:\n" + " mov __stack, %esp\n" + " popal\n" + ); } + __asm__ (".text\n""real_mode_switch_end:\n"); extern char real_mode_switch_end[]; @@ -161,16 +162,18 @@ do_vgabios(void) int i; for (i=0x400; i<0x500; i++) { - printk_debug("%02x%c", *(unsigned char *)i, i%16==15 ? '\n' : ' '); + printk_debug("%02x%c", *(unsigned char *)i, + i%16==15 ? '\n' : ' '); *(unsigned char *) i = 0; } - + for (i=0x400; i<0x500; i++) { - printk_debug("%02x%c", *(unsigned char *)i, i%16==15 ? '\n' : ' '); + printk_debug("%02x%c", *(unsigned char *)i, + i%16==15 ? '\n' : ' '); } - + dev = pci_find_class(PCI_CLASS_DISPLAY_VGA <<8, NULL); - + if (! dev) { printk_debug("NO VGA FOUND\n"); return; @@ -360,7 +363,7 @@ biosint( flags = stackflags; printk_debug("biosint: # 0x%lx, eax 0x%lx ebx 0x%lx ecx 0x%lx edx 0x%lx\n", - intnumber, eax, ebx, ecx, edx); + intnumber, eax, ebx, ecx, edx); printk_debug("biosint: ebp 0x%lx esp 0x%lx edi 0x%lx esi 0x%lx\n", ebp, esp, edi, esi); printk_debug("biosint: ip 0x%x cs 0x%x flags 0x%x\n", ip, cs, flags); // cases in a good compiler are just as good as your own tables. @@ -383,7 +386,7 @@ biosint( case PCIBIOS: ret = pcibios( &edi, &esi, &ebp, &esp, - &ebx, &edx, &ecx, &eax, &flags); + &ebx, &edx, &ecx, &eax, &flags); break; case MEMSIZE: // who cares. @@ -392,7 +395,7 @@ biosint( break; default: printk_info(__FUNCTION__ ": Unsupport int #0x%x\n", - intnumber); + intnumber); break; } if (ret) |