Intel cpus: cache actual size of the Flash ROM device
Cache was enabled for the last 4 MB below 4 GB when ramstage is
loaded. This does not cover the case of a 8 MB Flash and could
overlap with some system device placed at high memory.
Use the actual device size for the cache region. Mainboard
may override this with Kconfig CACHE_ROM_SIZE if necessary.
Change-Id: I622223b1e2af0b3c1831f3570b74eacfde7189dc
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/641
Tested-by: build bot (Jenkins)
Reviewed-by: Idwer Vollering <vidwer@gmail.com>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/cpu/intel/car/cache_as_ram_ht.inc b/src/cpu/intel/car/cache_as_ram_ht.inc
index 08f5b11..ed207db 100644
--- a/src/cpu/intel/car/cache_as_ram_ht.inc
+++ b/src/cpu/intel/car/cache_as_ram_ht.inc
@@ -25,6 +25,9 @@
#define CPU_MAXPHYADDR 36
#define CPU_PHYSMASK_HI (1 << (CPU_MAXPHYADDR - 32) - 1)
+/* Base address to cache all of Flash ROM, just below 4GB. */
+#define CACHE_ROM_BASE ((1<<22 - CONFIG_CACHE_ROM_SIZE>>10)<<10)
+
#define CACHE_AS_RAM_SIZE CONFIG_DCACHE_RAM_SIZE
#define CACHE_AS_RAM_BASE CONFIG_DCACHE_RAM_BASE
@@ -203,13 +206,13 @@
movl $CPU_PHYSMASK_HI, %edx
wrmsr
- /* Enable caching and Speculative Reads for the last 4MB. */
+ /* Enable caching and Speculative Reads for Flash ROM device. */
movl $MTRRphysBase_MSR(1), %ecx
- movl $(0xffc00000 | MTRR_TYPE_WRPROT), %eax
+ movl $(CACHE_ROM_BASE | MTRR_TYPE_WRPROT), %eax
xorl %edx, %edx
wrmsr
movl $MTRRphysMask_MSR(1), %ecx
- movl $(~(4 * 1024 * 1024 - 1) | MTRRphysMaskValid), %eax
+ movl $(~(CONFIG_CACHE_ROM_SIZE - 1) | MTRRphysMaskValid), %eax
movl $CPU_PHYSMASK_HI, %edx
wrmsr