SMM for AMD K8 Part 1/2

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>




git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6201 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 137 insertions, 0 deletions

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 <console/console.h>
+#include <arch/io.h>
+#include <cpu/cpu.h>
+#include <cpu/x86/lapic.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/mtrr.h>
+#include <cpu/amd/mtrr.h>
+#include <cpu/amd/model_fxx_msr.h>
+#include <cpu/x86/cache.h>
+#include <cpu/x86/smm.h>
+#include <string.h>
+
+#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);
+}