/*
* This file is part of the coreboot project.
*
- * Copyright (C) 2009 coresystems GmbH
+ * Copyright (C) 2009-2010 coresystems GmbH
*
* 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
/* This is the intXX interrupt handler stub code. It gets copied
* to the IDT and to some fixed addresses in the F segment. Before
- * the code can used, it gets patched up by the C function copying
+ * the code can used, it gets patched up by the C function copying
* it: byte 3 (the $0 in movb $0, %al) is overwritten with the int#.
*/
/* Realmode IDT pointer structure. */
.globl __realmode_idt
__realmode_idt = RELOCATED(.)
- .word 1023 /* 16-bit limit */
- .long 0 /* 24-bit base */
+ .word 1023 /* 16 bit limit */
+ .long 0 /* 24 bit base */
.word 0
/* Preserve old stack */
__stack = RELOCATED(.)
.long 0
+/* Register store for realmode_call and realmode_interrupt */
+__registers = RELOCATED(.)
+ .long 0 /* 0 - EAX */
+ .long 0 /* 4 - EBX */
+ .long 0 /* 8 - ECX */
+ .long 0 /* 12 - EDX */
+ .long 0 /* 16 - ESI */
+ .long 0 /* 20 - EDI */
+
+/* 256 byte buffer, used by int10 */
+ .globl __buffer
+__buffer = RELOCATED(.)
+ .skip 256
+
.code32
- .globl __run_optionrom
-__run_optionrom = RELOCATED(.)
+ .globl __realmode_call
+__realmode_call = RELOCATED(.)
/* save all registers to the stack */
pushal
/* Move the protected mode stack to a safe place */
- mov %esp, __stack
-
- /* Get devfn into %ecx */
+ movl %esp, __stack
movl %esp, %ebp
+
/* This function is called with regparm=0 and we have
- * to skip the 32 byte from pushal:
+ * to skip the 32 byte from pushal. Hence start at 36.
*/
- movl 36(%ebp), %ecx
+
+ /* entry point */
+ movl 36(%ebp), %eax
+ mov %ax, __lcall_instr + 1
+ andl $0xffff0000, %eax
+ shrl $4, %eax
+ mov %ax, __lcall_instr + 3
+
+ /* initial register values */
+ movl 40(%ebp), %eax
+ movl %eax, __registers + 0 /* eax */
+ movl 44(%ebp), %eax
+ movl %eax, __registers + 4 /* ebx */
+ movl 48(%ebp), %eax
+ movl %eax, __registers + 8 /* ecx */
+ movl 52(%ebp), %eax
+ movl %eax, __registers + 12 /* edx */
+ movl 56(%ebp), %eax
+ movl %eax, __registers + 16 /* esi */
+ movl 60(%ebp), %eax
+ movl %eax, __registers + 20 /* edi */
/* Activate the right segment descriptor real mode. */
ljmp $0x28, $RELOCATED(1f)
* protected mode is turned off.
*/
mov $0x30, %ax
- mov %ax, %ds
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
- mov %ax, %ss
+ mov %ax, %ds
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
+ mov %ax, %ss
/* Turn off protection */
movl %cr0, %eax
1:
/* Setup a stack: 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
+ * protected, since the 16 bit ESP at segment 0 will
* work for any case. */
mov $0x0, %ax
mov %ax, %ss
movl $0x1000, %eax
movl %eax, %esp
- /* Load our 16 bit idt */
+ /* Load 16 bit IDT */
xor %ax, %ax
mov %ax, %ds
lidt __realmode_idt
+ /* initialize registers for option rom lcall */
+ movl __registers + 0, %eax
+ movl __registers + 4, %ebx
+ movl __registers + 8, %ecx
+ movl __registers + 12, %edx
+ movl __registers + 16, %esi
+ movl __registers + 20, %edi
+
/* Set all segments to 0x0000, ds to 0x0040 */
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
+ push %ax
+ xor %ax, %ax
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
mov $0x40, %ax
mov %ax, %ds
- mov %cx, %ax // restore ax
+ pop %ax
/* ************************************ */
- // TODO this will not work for non-VGA option ROMs
- /* run VGA BIOS at 0xc000:0003 */
- lcall $0xc000, $0x0003
+__lcall_instr = RELOCATED(.)
+ .byte 0x9a
+ .word 0x0000, 0x0000
/* ************************************ */
- /* If we got here, just about done.
- * Need to get back to protected mode
+ /* If we got here, we are just about done.
+ * Need to get back to protected mode.
*/
movl %cr0, %eax
orl $PE, %eax
data32 ljmp $0x10, $RELOCATED(1f)
1:
.code32
- movw $0x18, %ax
- mov %ax, %ds
+ mov $0x18, %ax
+ mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
lidt idtarg
/* and exit */
- mov __stack, %esp
+ movl __stack, %esp
popal
- ret
- .globl __run_interrupt
-__run_interrupt = RELOCATED(.)
+ // TODO return AX from OPROM call
+ ret
- /* paranoia -- does ecx get saved? not sure. This is
- * the easiest safe thing to do. */
+ .globl __realmode_interrupt
+__realmode_interrupt = RELOCATED(.)
+ /* save all registers to the stack */
pushal
/* save the stack */
- mov %esp, __stack
+ movl %esp, __stack
+ movl %esp, %ebp
+
+ /* This function is called with regparm=0 and we have
+ * to skip the 32 byte from pushal. Hence start at 36.
+ */
+ /* prepare interrupt calling code */
+ movl 36(%ebp), %eax
+ movb %al, __intXX_instr + 1 /* intno */
+
+ /* initial register values */
+ movl 40(%ebp), %eax
+ movl %eax, __registers + 0 /* eax */
+ movl 44(%ebp), %eax
+ movl %eax, __registers + 4 /* ebx */
+ movl 48(%ebp), %eax
+ movl %eax, __registers + 8 /* ecx */
+ movl 52(%ebp), %eax
+ movl %eax, __registers + 12 /* edx */
+ movl 56(%ebp), %eax
+ movl %eax, __registers + 16 /* esi */
+ movl 60(%ebp), %eax
+ movl %eax, __registers + 20 /* edi */
/* This configures CS properly for real mode. */
ljmp $0x28, $RELOCATED(1f)
1:
.code16 /* 16 bit code from here on... */
- // DEBUG
- movb $0xec, %al
- outb %al, $0x80
-
/* 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
- mov %ax, %ds
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
- mov %ax, %ss
+ mov $0x30, %ax
+ mov %ax, %ds
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
+ mov %ax, %ss
/* Turn off protected mode */
- movl %cr0, %eax
+ movl %cr0, %eax
andl $~PE, %eax
- movl %eax, %cr0
+ movl %eax, %cr0
/* Now really going into real mode */
data32 ljmp $0, $RELOCATED(1f)
1:
- /* 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.
+ /* put the stack at the end of page zero. That way we can easily
+ * share it between real mode and protected mode, because %esp and
+ * %ss:%sp point to the same memory.
*/
/* setup a stack */
mov $0x0, %ax
movl %eax, %esp
/* Load 16-bit intXX IDT */
- xor %ax, %ax
+ xor %ax, %ax
mov %ax, %ds
lidt __realmode_idt
+ /* initialize registers for intXX call */
+ movl __registers + 0, %eax
+ movl __registers + 4, %ebx
+ movl __registers + 8, %ecx
+ movl __registers + 12, %edx
+ movl __registers + 16, %esi
+ movl __registers + 20, %edi
+
/* Set all segments to 0x0000 */
+ push %ax
+ xor %ax, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov %ax, %gs
+ pop %ax
- /* Call VGA BIOS int10 function 0x4f14 to enable main console
- * Epia-M does not always autosence the main console so forcing
- * it on is good.
- */
-
- /* Ask VGA option rom to enable main console */
- movw $0x4f14,%ax
- movw $0x8003,%bx
- movw $1, %cx
- movw $0, %dx
- movw $0, %di
- int $0x10
+__intXX_instr = RELOCATED(.)
+ .byte 0xcd, 0x00 /* This becomes intXX */
/* Ok, the job is done, now go back to protected mode coreboot */
movl %cr0, %eax
data32 ljmp $0x10, $RELOCATED(1f)
1:
.code32
- movw $0x18, %ax
+ mov $0x18, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
lidt idtarg
/* Exit */
- mov __stack, %esp
+ movl __stack, %esp
popal
ret
/* This is the 16-bit interrupt entry point called by the IDT stub code.
+ *
* Before this code code is called, %eax is pushed to the stack, and the
- * interrupt number is loaded into %al
+ * interrupt number is loaded into %al. On return this function cleans up
+ * for its caller.
*/
.code16
__interrupt_handler_16bit = RELOCATED(.)
data32 ljmp $0x10, $RELOCATED(1f)
1:
.code32
- movw $0x18, %ax
+ mov $0x18, %ax
mov %ax, %ds
mov %ax, %es
mov %ax, %fs
mov $0x0, %ax
mov %ax, %ss
- /* Restore 16-bit IDT */
+ /* Restore 16 bit IDT */
xor %ax, %ax
mov %ax, %ds
lidt __realmode_idt
- /* Set up our segment registers to segment 0x0000 */
- mov %ax, %es
- mov %ax, %fs
- mov %ax, %gs
- mov $0x40, %ax
- mov %ax, %ds
-
/* Restore all registers, including those
* manipulated by the C handler
*/