diff options
Diffstat (limited to 'util/x86emu/x86_asm.S')
| -rw-r--r-- | util/x86emu/x86_asm.S | 347 |
1 files changed, 0 insertions, 347 deletions
diff --git a/util/x86emu/x86_asm.S b/util/x86emu/x86_asm.S deleted file mode 100644 index 616aa8675f..0000000000 --- a/util/x86emu/x86_asm.S +++ /dev/null @@ -1,347 +0,0 @@ -/* - * This file is part of the coreboot project. - * - * Copyright (C) 2009 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 - * the Free Software Foundation; version 2 of the License. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. - */ - -#define REALMODE_BASE 0x600 -#define RELOCATED(x) (x - __realmode_code + REALMODE_BASE) - -/* CR0 bits */ -#define PE (1 << 0) - -/* 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 - * it: byte 3 (the $0 in movb $0, %al) is overwritten with the int#. - */ - - .code16 - .globl __idt_handler -__idt_handler: - pushal - movb $0, %al /* This instruction gets modified */ - ljmp $0, $__interrupt_handler_16bit - .globl __idt_handler_size -__idt_handler_size = ( . - __idt_handler) - - -/* In order to be independent of coreboot's position in RAM - * we relocate a part of the code to the low megabyte, so the - * CPU can use it in real-mode. This code lives at __realmode_code. - */ - .globl __realmode_code -__realmode_code: - -/* Realmode IDT pointer structure. */ - .globl __realmode_idt -__realmode_idt = RELOCATED(.) - .word 1023 /* 16-bit limit */ - .long 0 /* 24-bit base */ - .word 0 - -/* Preserve old stack */ -__stack = RELOCATED(.) - .long 0 - - .code32 - .globl __run_optionrom -__run_optionrom = 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, %ebp - /* This function is called with regparm=0 and we have - * to skip the 32 byte from pushal: - */ - movl 36(%ebp), %ecx - - /* Activate the right segment descriptor real mode. */ - ljmp $0x28, $RELOCATED(1f) -1: -.code16 - /* 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 - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss - - /* Turn off protection */ - movl %cr0, %eax - andl $~PE, %eax - movl %eax, %cr0 - - /* Now really going into real mode */ - ljmp $0, $RELOCATED(1f) -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 - * work for any case. */ - mov $0x0, %ax - mov %ax, %ss - movl $0x1000, %eax - movl %eax, %esp - - /* Load our 16 bit idt */ - xor %ax, %ax - mov %ax, %ds - lidt __realmode_idt - - /* Set all segments to 0x0000, ds to 0x0040 */ - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov $0x40, %ax - mov %ax, %ds - mov %cx, %ax // restore ax - - /* ************************************ */ - // TODO this will not work for non-VGA option ROMs - /* run VGA BIOS at 0xc000:0003 */ - lcall $0xc000, $0x0003 - /* ************************************ */ - - /* If we got here, just about done. - * Need to get back to protected mode - */ - movl %cr0, %eax - orl $PE, %eax - movl %eax, %cr0 - - /* Now that we are in protected mode - * jump to a 32 bit code segment. - */ - data32 ljmp $0x10, $RELOCATED(1f) -1: - .code32 - movw $0x18, %ax - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss - - /* restore proper idt */ - lidt idtarg - - /* and exit */ - mov __stack, %esp - popal - ret - - .globl __run_interrupt -__run_interrupt = RELOCATED(.) - - /* paranoia -- does ecx get saved? not sure. This is - * the easiest safe thing to do. */ - pushal - /* save the stack */ - mov %esp, __stack - - - /* 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 - - /* Turn off protected mode */ - movl %cr0, %eax - andl $~PE, %eax - 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. - */ - /* setup a stack */ - mov $0x0, %ax - mov %ax, %ss - movl $0x1000, %eax - movl %eax, %esp - - /* Load 16-bit intXX IDT */ - xor %ax, %ax - mov %ax, %ds - lidt __realmode_idt - - /* Set all segments to 0x0000 */ - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - - /* 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 - - /* Ok, the job is done, now go back to protected mode coreboot */ - movl %cr0, %eax - orl $PE, %eax - movl %eax, %cr0 - - /* Now that we are in protected mode jump to a 32-bit code segment. */ - data32 ljmp $0x10, $RELOCATED(1f) -1: - .code32 - movw $0x18, %ax - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss - - /* restore coreboot's 32-bit IDT */ - lidt idtarg - - /* Exit */ - mov __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 - */ - .code16 -__interrupt_handler_16bit = RELOCATED(.) - push %ds - push %es - push %fs - push %gs - - /* Clean up the interrupt number. We could have done this in the stub, - * but it would have cost 2 more bytes per stub entry. - */ - andl $0xff, %eax - pushl %eax /* ... and make it the first parameter */ - - /* Switch to protected mode */ - movl %cr0, %eax - orl $PE, %eax - movl %eax, %cr0 - - /* ... and jump to a 32 bit code segment. */ - data32 ljmp $0x10, $RELOCATED(1f) -1: - .code32 - movw $0x18, %ax - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss - - lidt idtarg - - /* Call the C interrupt handler */ - movl $interrupt_handler, %eax - call *%eax - - /* Now return to real mode ... */ - ljmp $0x28, $RELOCATED(1f) -1: - .code16 - /* Load the segment registers with 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 - - /* Disable Protected Mode */ - movl %cr0, %eax - andl $~PE, %eax - movl %eax, %cr0 - - /* Now really going into real mode */ - ljmp $0, $RELOCATED(1f) -1: - /* Restore real-mode stack segment */ - mov $0x0, %ax - mov %ax, %ss - - /* 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 - */ - popl %eax - pop %gs - pop %fs - pop %es - pop %ds - popal - iret - - .globl __realmode_code_size -__realmode_code_size = (. - __realmode_code) - - .code32 |