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-rw-r--r--src/northbridge/intel/x4x/ram_calc.c34
1 files changed, 33 insertions, 1 deletions
diff --git a/src/northbridge/intel/x4x/ram_calc.c b/src/northbridge/intel/x4x/ram_calc.c
index 2a5d7e5752..410e3b623a 100644
--- a/src/northbridge/intel/x4x/ram_calc.c
+++ b/src/northbridge/intel/x4x/ram_calc.c
@@ -20,11 +20,14 @@
#include <cbmem.h>
#include <commonlib/helpers.h>
#include <stdint.h>
+#include <arch/cpu.h>
#include <arch/io.h>
#include <device/pci_def.h>
#include <console/console.h>
#include <cpu/intel/romstage.h>
+#include <cpu/x86/mtrr.h>
#include <northbridge/intel/x4x/x4x.h>
+#include <program_loading.h>
/** Decodes used Graphics Mode Select (GMS) to kilobytes. */
u32 decode_igd_memory_size(const u32 gms)
@@ -100,7 +103,36 @@ void *cbmem_top(void)
return (void *) top_of_ram;
}
+#define ROMSTAGE_RAM_STACK_SIZE 0x5000
+
+/* setup_stack_and_mtrrs() determines the stack to use after
+ * cache-as-ram is torn down as well as the MTRR settings to use. */
void *setup_stack_and_mtrrs(void)
{
- return (void*)CONFIG_RAMTOP;
+ struct postcar_frame pcf;
+ uintptr_t top_of_ram;
+
+ if (postcar_frame_init(&pcf, ROMSTAGE_RAM_STACK_SIZE))
+ die("Unable to initialize postcar frame.\n");
+
+ /* Cache the ROM as WP just below 4GiB. */
+ postcar_frame_add_mtrr(&pcf, -CACHE_ROM_SIZE, CACHE_ROM_SIZE,
+ MTRR_TYPE_WRPROT);
+
+ /* Cache RAM as WB from 0 -> CACHE_TMP_RAMTOP. */
+ postcar_frame_add_mtrr(&pcf, 0, CACHE_TMP_RAMTOP, MTRR_TYPE_WRBACK);
+
+ /* Cache two separate 4 MiB regions below the top of ram, this
+ * satisfies MTRR alignment requirements. If you modify this to
+ * cover TSEG, make sure UMA region is not set with WRBACK as it
+ * causes hard-to-recover boot failures.
+ */
+ top_of_ram = (uintptr_t)cbmem_top();
+ postcar_frame_add_mtrr(&pcf, top_of_ram - 4*MiB, 4*MiB, MTRR_TYPE_WRBACK);
+ postcar_frame_add_mtrr(&pcf, top_of_ram - 8*MiB, 4*MiB, MTRR_TYPE_WRBACK);
+
+ /* Save the number of MTRRs to setup. Return the stack location
+ * pointing to the number of MTRRs.
+ */
+ return postcar_commit_mtrrs(&pcf);
}