From cadc54583877db65f33d2db11088d5fae1b77b74 Mon Sep 17 00:00:00 2001 From: Stefan Reinauer Date: Sat, 18 Dec 2010 23:29:37 +0000 Subject: SMM for AMD K8 Part 1/2 Signed-off-by: Stefan Reinauer Acked-by: Stefan Reinauer git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6201 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- src/cpu/amd/smm/smm_init.c | 137 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 src/cpu/amd/smm/smm_init.c (limited to 'src/cpu/amd/smm/smm_init.c') diff --git a/src/cpu/amd/smm/smm_init.c b/src/cpu/amd/smm/smm_init.c new file mode 100644 index 0000000000..d6f728bbba --- /dev/null +++ b/src/cpu/amd/smm/smm_init.c @@ -0,0 +1,137 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2010 coresystems GmbH + * Copyright (C) 2010 Rudolf Marek + * + * 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 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SMM_BASE_MSR 0xc0010111 +#define SMM_ADDR_MSR 0xc0010112 +#define SMM_MASK_MSR 0xc0010113 +#define SMM_BASE 0xa0000 + +extern unsigned char _binary_smm_start; +extern unsigned char _binary_smm_size; + +static int smm_handler_copied = 0; + +void smm_init(void) +{ + msr_t msr; + + msr = rdmsr(HWCR_MSR); + if (msr.lo & (1 << 0)) { + // This sounds like a bug... ? + printk(BIOS_DEBUG, "SMM is still locked from last boot, using old handler.\n"); + return; + } + + /* Only copy SMM handler once, not once per CPU */ + if (!smm_handler_copied) { + msr_t syscfg_orig, mtrr_aseg_orig; + + smm_handler_copied = 1; + + /* MTRR changes don't like an enabled cache */ + disable_cache(); + + /* Back up MSRs for later restore */ + syscfg_orig = rdmsr(SYSCFG_MSR); + mtrr_aseg_orig = rdmsr(MTRRfix16K_A0000_MSR); + + msr = syscfg_orig; + /* Allow changes to MTRR extended attributes */ + msr.lo |= SYSCFG_MSR_MtrrFixDramModEn; + /* turn the extended attributes off until we fix + * them so A0000 is routed to memory + */ + msr.lo &= ~SYSCFG_MSR_MtrrFixDramEn; + wrmsr(SYSCFG_MSR, msr); + + /* set DRAM access to 0xa0000 */ + /* A0000 is memory */ + msr.lo = 0x18181818; + msr.hi = 0x18181818; + wrmsr(MTRRfix16K_A0000_MSR, msr); + enable_cache(); + + /* disable the extended features */ + msr = syscfg_orig; + msr.lo |= SYSCFG_MSR_MtrrFixDramModEn; + msr.lo |= SYSCFG_MSR_MtrrFixDramEn; + wrmsr(SYSCFG_MSR, msr); + + /* enable the SMM memory window */ + // TODO does "Enable ASEG SMRAM Range" have to happen on + // every CPU core? + msr = rdmsr(SMM_MASK_MSR); + msr.lo |= (1 << 0); // Enable ASEG SMRAM Range + msr.lo &= ~(1 << 2); // Open ASEG SMRAM Range + wrmsr(SMM_MASK_MSR, msr); + + /* copy the real SMM handler */ + memcpy((void *)SMM_BASE, &_binary_smm_start, (size_t)&_binary_smm_size); + wbinvd(); + + msr = rdmsr(SMM_MASK_MSR); + msr.lo |= ~(1 << 2); // Close ASEG SMRAM Range + wrmsr(SMM_MASK_MSR, msr); + + /* Change SYSCFG so we can restore the MTRR */ + msr = syscfg_orig; + msr.lo |= SYSCFG_MSR_MtrrFixDramModEn; + msr.lo &= ~SYSCFG_MSR_MtrrFixDramEn; + wrmsr(SYSCFG_MSR, msr); + + /* Restore MTRR */ + disable_cache(); + wrmsr(MTRRfix16K_A0000_MSR, mtrr_aseg_orig); + + /* Restore SYSCFG */ + wrmsr(SYSCFG_MSR, syscfg_orig); + enable_cache(); + } + + /* But set SMM base address on all CPUs/cores */ + msr = rdmsr(SMM_BASE_MSR); + msr.lo = SMM_BASE - (lapicid() * 0x400); + wrmsr(SMM_BASE_MSR, msr); +} + +void smm_lock(void) +{ + // TODO I think this should be running on each CPU + msr_t msr; + + printk(BIOS_DEBUG, "Locking SMM.\n"); + + /* Set SMMLOCK to avoid exploits messing with SMM */ + msr = rdmsr(HWCR_MSR); + msr.lo |= (1 << 0); + wrmsr(HWCR_MSR, msr); +} -- cgit v1.2.3