diff options
author | Patrick Georgi <patrick.georgi@secunet.com> | 2012-11-22 10:39:16 +0100 |
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committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2012-11-24 20:05:00 +0100 |
commit | 3e77eb6d1e0a3ff9c0a32504a5221dc57b10506c (patch) | |
tree | 00252b38808ea5d6dbb16548e4c5509e5dffb647 /src/devices/oprom/x86_asm.S | |
parent | 6b11c8be4572f9b96804509e5bd9170a8cec162d (diff) |
x86emu: Move realmode handler into own directory
It's really a feature in parallel to YABEL/x86emu. Reflect this in
the directory structure.
Change-Id: Ie88e4fa6bfef13d23c55b2db3faacbd90f8cc30b
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/1889
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/devices/oprom/x86_asm.S')
-rw-r--r-- | src/devices/oprom/x86_asm.S | 413 |
1 files changed, 0 insertions, 413 deletions
diff --git a/src/devices/oprom/x86_asm.S b/src/devices/oprom/x86_asm.S deleted file mode 100644 index 56ebb3a885..0000000000 --- a/src/devices/oprom/x86_asm.S +++ /dev/null @@ -1,413 +0,0 @@ -/* - * This file is part of the coreboot project. - * - * 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 - * 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 - -/* 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 __realmode_call -__realmode_call = RELOCATED(.) - /* save all registers to the stack */ - pusha - pushf - - /* Move the protected mode stack pointer to a safe place */ - movl %esp, __stack - movl %esp, %ebp - - /* This function is called with regparm=0 and we have to - * skip the 36 byte from pushf+pusha. Hence start at 40. - */ - - /* entry point */ - movl 40(%ebp), %eax - mov %ax, __lcall_instr + 1 - andl $0xffff0000, %eax - shrl $4, %eax - mov %ax, __lcall_instr + 3 - - /* initial register values */ - movl 44(%ebp), %eax - movl %eax, __registers + 0 /* eax */ - movl 48(%ebp), %eax - movl %eax, __registers + 4 /* ebx */ - movl 52(%ebp), %eax - movl %eax, __registers + 8 /* ecx */ - movl 56(%ebp), %eax - movl %eax, __registers + 12 /* edx */ - movl 60(%ebp), %eax - movl %eax, __registers + 16 /* esi */ - movl 64(%ebp), %eax - movl %eax, __registers + 20 /* edi */ - - /* 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 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 */ - push %ax - xor %ax, %ax - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov $0x40, %ax - mov %ax, %ds - pop %ax - - /* ************************************ */ -__lcall_instr = RELOCATED(.) - .byte 0x9a - .word 0x0000, 0x0000 - /* ************************************ */ - - /* If we got here, we are 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 - mov $0x18, %ax - mov %ax, %ds - mov %ax, %es - mov %ax, %fs - mov %ax, %gs - mov %ax, %ss - - /* restore proper idt */ - lidt idtarg - - /* restore stack pointer, eflags and register values */ - movl __stack, %esp - popf - popa - - /* and exit */ - // TODO return AX from OPROM call - ret - - .globl __realmode_interrupt -__realmode_interrupt = RELOCATED(.) - /* save all registers to the stack */ - pusha - pushf - - /* save the stack pointer */ - movl %esp, __stack - movl %esp, %ebp - - /* This function is called with regparm=0 and we have to - * skip the 36 byte from pushf+pusha. Hence start at 40. - */ - - /* prepare interrupt calling code */ - movl 40(%ebp), %eax - movb %al, __intXX_instr + 1 /* intno */ - - /* initial register values */ - movl 44(%ebp), %eax - movl %eax, __registers + 0 /* eax */ - movl 48(%ebp), %eax - movl %eax, __registers + 4 /* ebx */ - movl 52(%ebp), %eax - movl %eax, __registers + 8 /* ecx */ - movl 56(%ebp), %eax - movl %eax, __registers + 12 /* edx */ - movl 60(%ebp), %eax - movl %eax, __registers + 16 /* esi */ - movl 64(%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... */ - - /* 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 mode and protected mode, because %esp and - * %ss:%sp point to the same memory. - */ - /* 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 - - /* 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 - -__intXX_instr = RELOCATED(.) - .byte 0xcd, 0x00 /* This becomes intXX */ - - /* 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 - mov $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 - - /* restore stack pointer, eflags and register values and exit */ - movl __stack, %esp - popf - popa - 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. On return this function cleans up - * for its caller. - */ - .code16 -__interrupt_handler_16bit = RELOCATED(.) - push %ds - push %es - push %fs - push %gs - - /* Clear DF to not break ABI assumptions */ - cld - - /* 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 - mov $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 - - /* 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 |