This is what's currently in my v3 VIA CAR tree. Needs more work (comments, code, copyrights, makefiles). Just FYI. I'll work on it some more, then submit.
Sent to make Bari and Corey happy and give them a reasonably close preview.
Regards, Carl-Daniel
Index: arch/x86/via/stage0.S =================================================================== --- arch/x86/via/stage0.S (Revision 0) +++ arch/x86/via/stage0.S (Revision 0) @@ -0,0 +1,190 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2000,2007 Ronald G. Minnich rminnich@gmail.com + * Copyright (C) 2005 Eswar Nallusamy, LANL + * Copyright (C) 2005 Tyan + * (Written by Yinghai Lu yhlu@tyan.com for Tyan) + * Copyright (C) 2007 coresystems GmbH + * (Written by Stefan Reinauer stepan@coresystems.de for coresystems GmbH) + * Copyright (C) 2007,2008 Carl-Daniel Hailfinger + * Copyright (C) 2008 VIA Technologies, Inc. + * (Written by Jason Zhao jasonzhao@viatech.com.cn for VIA) + * + * 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 + */ + +/* Init code - Switch CPU to protected mode and enable Cache-as-Ram (CAR). */ + +#include <macros.h> + + .align 4 + .globl protected_stage0 +protected_stage0: + /* This code was used by v2. TODO. */ + lgdt %cs:gdtptr + ljmp $ROM_CODE_SEG, $__protected_stage0 + +.globl __protected_stage0 +__protected_stage0: + /* Save the BIST result. */ + movl %eax, %ebp + + port80_post(0x01) + + movw $ROM_DATA_SEG, %ax + movw %ax, %ds + movw %ax, %es + movw %ax, %ss + movw %ax, %fs + movw %ax, %gs + + /* Restore the BIST value to %eax. */ + movl %ebp, %eax + +.align 4 + +#define CacheSize CONFIG_CARSIZE +#define CacheBase CONFIG_CARBASE + +#include <mtrr.h> + + /* Save the BIST result */ + movl %eax, %ebp + +CacheAsRam: + + /* disable cache */ + movl %cr0, %eax + orl $(0x1<<30),%eax + movl %eax,%cr0 + invd + + /* Set the default memory type and enable fixed and variable MTRRs */ + movl $MTRRdefType_MSR, %ecx + xorl %edx, %edx + /* Enable Variable and Fixed MTRRs */ + movl $0x00000c00, %eax + wrmsr + + /* Clear all MTRRs */ + xorl %edx, %edx + movl $fixed_mtrr_msr, %esi + +clear_fixed_var_mtrr: + lodsl (%esi), %eax + testl %eax, %eax + jz clear_fixed_var_mtrr_out + + movl %eax, %ecx + xorl %eax, %eax + wrmsr + + jmp clear_fixed_var_mtrr +clear_fixed_var_mtrr_out: + /* MTRRPhysBase */ + movl $0x200, %ecx + xorl %edx, %edx + movl $(CacheBase|MTRR_TYPE_WRBACK),%eax + wrmsr + + /* MTRRPhysMask */ + movl $0x201, %ecx + /* This assumes we never access addresses above 2^36 in CAR. */ + movl $0x0000000f,%edx + movl $(~(CacheSize-1)|0x800),%eax + wrmsr + + /* enable write base caching so we can do execute in place + * on the flash rom. + */ + /* MTRRPhysBase */ + movl $0x202, %ecx + xorl %edx, %edx + movl $(XIP_ROM_BASE|MTRR_TYPE_WRBACK),%eax + wrmsr + + /* MTRRPhysMask */ + movl $0x203, %ecx + movl $0x0000000f,%edx + movl $(~(XIP_ROM_SIZE - 1) | 0x800), %eax + wrmsr + + + movl $MTRRdefType_MSR, %ecx + xorl %edx, %edx + /* Enable Variable and Fixed MTRRs */ + movl $0x00000800, %eax + wrmsr + + /* enable cache */ + movl %cr0, %eax + andl $0x9fffffff,%eax + movl %eax, %cr0 + + /* Read the range with lodsl */ + cld + movl $CacheBase, %esi + movl $(CacheSize >> 2), %ecx + rep lodsl + + /* Clear the range */ + movl $CacheBase, %edi + movl $(CacheSize >> 2), %ecx + xorl %eax, %eax + rep stosl + + /* Read the XIP area */ + movl XIP_ROM_BASE, %esi + movl $(XIP_ROM_SIZE>>2), %ecx + rep lodsl + + /* The key point of this CAR code is C7 cache does not turn into + * "no fill" mode, which is not compatible with general CAR code. + */ + + /* set up the stack pointer */ + movl $(CacheBase + CacheSize - 4), %eax + movl %eax, %esp + + /* Store zero for the pointer to the global variables. */ + pushl $0 + + /* Restore the BIST result. */ + movl %ebp, %eax + + /* We need to set ebp? No need. */ + movl %esp, %ebp + + /* Second parameter: init_detected */ + /* Store zero for the unused init_detected parameter. */ + pushl $0 + /* First parameter: bist */ + pushl %eax + call stage1_main + /* We will not go back. */ + +fixed_mtrr_msr: + .long 0x250, 0x258, 0x259 + .long 0x268, 0x269, 0x26A + .long 0x26B, 0x26C, 0x26D + .long 0x26E, 0x26F +var_mtrr_msr: + .long 0x200, 0x201, 0x202, 0x203 + .long 0x204, 0x205, 0x206, 0x207 + .long 0x208, 0x209, 0x20A, 0x20B + .long 0x20C, 0x20D, 0x20E, 0x20F + .long 0x000 /* NULL, end of table */ + +#include "../stage0_common.S"