Comments
Patch
===================================================================
@@ -1,5 +1,6 @@
#include <console/console.h>
#include <device/device.h>
+#include <arch/cpu.h>
#include <cpu/x86/mtrr.h>
#include <cpu/amd/mtrr.h>
#include <cpu/x86/cache.h>
@@ -175,11 +176,13 @@
enable_cache();
- /* FIXME we should probably query the cpu for this
- * but so far this is all any recent AMD cpu has supported.
- */
address_bits = CONFIG_CPU_ADDR_BITS; //K8 could be 40, and GH could be 48
+ /* AMD specific MSR to query number of address bits */
+ if (cpuid_eax(0x80000000) >= 0x80000008) {
+ address_bits = cpuid_eax(0x80000008) & 0xff;
+ }
+
/* Now that I have mapped what is memory and what is not
* Setup the mtrrs so we can cache the memory.
*/
This fixes a FIXME in src/cpu/amd/mtrr/amd_mtrr.c and shuts up the Linux kernel, which was previously complaining that the MTRR setup is wrong, if the cpu supports more than CONFIG_CPU_ADDR_BITS bits of address space. Shamelessly copied from Linux arch/x86/kernel/cpu/mtrr/main.c Signed-off-by: Tobias Diedrich <ranma+coreboot@tdiedrich.de> ---