2 files changed, 32 insertions, 0 deletions
diff --git a/src/cpu/amd/car/cache_as_ram.inc b/src/cpu/amd/car/cache_as_ram.inc
index 162680db73..94990a66f7 100644
--- a/src/cpu/amd/car/cache_as_ram.inc
+++ b/src/cpu/amd/car/cache_as_ram.inc
@@ -27,6 +27,8 @@
 /* for CAR_FAM10 */
 #define CacheSizeAPStack 0x400 /* 1K */
 
+#define MSR_FAM10      0xC001102A
+
 #define jmp_if_k8(x)	comisd	%xmm2, %xmm1; jb x
 
 #define CPUID_MASK		0x0ff00f00
@@ -122,6 +124,22 @@ CAR_FAM10_out:
 	bts	$15, %eax
 	wrmsr
 
+	/* Erratum 343, RevGuide for Fam10h, Pub#41322 Rev. 3.33 */
+
+	/* read-address has to be stored in the ecx register */
+	movl    $MSR_FAM10, %ecx
+
+	/* execute special read command for msr-register. Result is then in the EDX:EAX-registers (MSBs in EDX) */
+	rdmsr
+
+	/* Set bit 35 to 1 in EAX */
+	bts     $35, %eax
+
+	/* write back the modified register EDX:EAX to the MSR specified in ECX */
+	wrmsr
+
+	/* Erratum 343 end */
+
 CAR_FAM10_out_post_errata:
 
 	/* Set MtrrFixDramModEn for clear fixed mtrr */
diff --git a/src/cpu/amd/car/post_cache_as_ram.c b/src/cpu/amd/car/post_cache_as_ram.c
index ce8ef19647..89366e0e33 100644
--- a/src/cpu/amd/car/post_cache_as_ram.c
+++ b/src/cpu/amd/car/post_cache_as_ram.c
@@ -23,7 +23,19 @@ static void inline __attribute__((always_inline))  memcopy(void *dest, const voi
                 : "S" (src), "D" (dest), "c" ((bytes)>>2)
                 );
 }
+/* Disable Erratum 343 Workaround, see RevGuide for Fam10h, Pub#41322 Rev 3.33 */
 
+static void vErrata343(void)
+{
+    msr_t msr;
+    unsigned int uiMask = 0xFFFFFFF7;
+
+#ifdef BU_CFG2_MSR
+    msr = rdmsr(BU_CFG2_MSR);
+    msr.hi &= uiMask; // set bit 35 to 0
+    wrmsr(BU_CFG2_MSR, msr);
+#endif
+}
 
 static void post_cache_as_ram(void)
 {
@@ -56,6 +68,8 @@ static void post_cache_as_ram(void)
 	print_debug("Copying data from cache to RAM -- switching to use RAM as stack... ");
 
 	/* from here don't store more data in CAR */
+	vErrata343();
+
 #if 0
         __asm__ volatile (
         	"pushl  %eax\n\t"