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authorScott Duplichan <scott@notabs.org>2011-02-10 20:49:56 +0000
committerScott Duplichan <scott@notabs.org>2011-02-10 20:49:56 +0000
commitdaecb1888ee813978a1d177a02ffd394445966a9 (patch)
tree1c53c517567ef7d441c1b035c82ddaf5f645988f /src
parent20ecc5af40adbd63a3a55eefe7e53bd16412c712 (diff)
downloadcoreboot-daecb1888ee813978a1d177a02ffd394445966a9.tar.xz
According to AMD documentation, cache type WP should be used for
execution from flash memory. Coreboot uses WB. While there is no noticeable performance difference between the two settings, use of WB can cause a problem for a jtag debugger. The attached patch changes AMD cache as ram setting for flash execution from WB to WP. Signed-off-by: Scott Duplichan <scott@notabs.org> Acked-by: Marc Jones <marcj303@gmail.com> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6342 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src')
-rw-r--r--src/cpu/amd/car/cache_as_ram.inc4
1 files changed, 2 insertions, 2 deletions
diff --git a/src/cpu/amd/car/cache_as_ram.inc b/src/cpu/amd/car/cache_as_ram.inc
index 7f66f363ef..26cdec3fbe 100644
--- a/src/cpu/amd/car/cache_as_ram.inc
+++ b/src/cpu/amd/car/cache_as_ram.inc
@@ -294,11 +294,11 @@ clear_fixed_var_mtrr_out:
xorl %edx, %edx
/*
* IMPORTANT: The two lines below can _not_ be written like this:
- * movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRBACK), %eax
+ * movl $(REAL_XIP_ROM_BASE | MTRR_TYPE_WRPROT), %eax
* http://www.coreboot.org/pipermail/coreboot/2010-October/060855.html
*/
movl $REAL_XIP_ROM_BASE, %eax
- orl $MTRR_TYPE_WRBACK, %eax
+ orl $MTRR_TYPE_WRPROT, %eax
wrmsr
movl $MTRRphysMask_MSR(1), %ecx