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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2015-2016 Intel Corporation
*
* 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.
*
*/
#include <rules.h>
#include <cpu/x86/mtrr.h>
#include <cpu/x86/cache.h>
#include <cpu/x86/post_code.h>
.section ".text"
.global car_stage_entry
car_stage_entry:
/* Enter the C code */
call car_stage_c_entry
/*
* Car teardown
*/
/*
* eax: New stack address
*/
/* Switch to the stack in RAM */
movl %eax, %esp
/* chipset_teardown_car() is expected to disable cache-as-ram. */
call chipset_teardown_car
/* Display the MTRRs */
call soc_display_mtrrs
/*
* The stack contents are initialized in src/soc/intel/common/stack.c
* to be the following:
*
* *
* *
* *
* +36: MTRR mask 1 63:32
* +32: MTRR mask 1 31:0
* +28: MTRR base 1 63:32
* +24: MTRR base 1 31:0
* +20: MTRR mask 0 63:32
* +16: MTRR mask 0 31:0
* +12: MTRR base 0 63:32
* +8: MTRR base 0 31:0
* +4: Number of MTRRs to setup (described above)
* +0: Number of variable MTRRs to clear
*/
/* Clear all of the variable MTRRs. */
popl %ebx
movl $MTRR_PHYS_BASE(0), %ecx
clr %eax
clr %edx
1:
testl %ebx, %ebx
jz 1f
wrmsr /* Write MTRR base. */
inc %ecx
wrmsr /* Write MTRR mask. */
inc %ecx
dec %ebx
jmp 1b
1:
/* Get number of MTRRs. */
popl %ebx
movl $MTRR_PHYS_BASE(0), %ecx
2:
testl %ebx, %ebx
jz 2f
/* Low 32 bits of MTRR base. */
popl %eax
/* Upper 32 bits of MTRR base. */
popl %edx
/* Write MTRR base. */
wrmsr
inc %ecx
/* Low 32 bits of MTRR mask. */
popl %eax
/* Upper 32 bits of MTRR mask. */
popl %edx
/* Write MTRR mask. */
wrmsr
inc %ecx
dec %ebx
jmp 2b
2:
post_code(0x39)
/* And enable cache again after setting MTRRs. */
movl %cr0, %eax
andl $~(CR0_CacheDisable | CR0_NoWriteThrough), %eax
movl %eax, %cr0
post_code(0x3a)
/* Enable MTRR. */
movl $MTRR_DEF_TYPE_MSR, %ecx
rdmsr
orl $MTRR_DEF_TYPE_EN, %eax
wrmsr
post_code(0x3b)
/* Invalidate the cache again. */
invd
__main:
post_code(POST_PREPARE_RAMSTAGE)
cld /* Clear direction flag. */
call copy_and_run
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