1 files changed, 53 insertions, 0 deletions
diff --git a/src/cpu/amd/car/clear_1m_ram.c b/src/cpu/amd/car/clear_1m_ram.c
new file mode 100644
index 0000000000..85ba59cf73
--- /dev/null
+++ b/src/cpu/amd/car/clear_1m_ram.c
@@ -0,0 +1,53 @@
+/* by yhlu 6.2005 */
+/* be warned, this file will be used core 0/node 0 only */
+        __asm__ volatile (
+
+        /* disable cache */
+        "movl    %cr0, %eax\n\t"
+        "orl    $(0x1<<30),%eax\n\t"
+        "movl    %eax, %cr0\n\t"
+
+        /* enable caching for first 1M using variable mtrr */
+        "movl    $0x200, %ecx\n\t"
+        "xorl    %edx, %edx\n\t"
+        "movl     $(0 | 1), %eax\n\t"
+//	"movl     $(0 | MTRR_TYPE_WRCOMB), %eax\n\t"
+        "wrmsr\n\t"
+
+        "movl    $0x201, %ecx\n\t"
+        "movl    $0x0000000f, %edx\n\t" 
+        "movl    $((~(( 0 + 0x100000) - 1)) | 0x800), %eax\n\t"
+        "wrmsr\n\t"
+
+        /* clear the first 1M */
+        "movl    $0x0, %edi\n\t"
+        "cld\n\t"
+        "movl    $(0x100000>>2), %ecx\n\t"
+        "xorl    %eax, %eax\n\t"
+        "rep     stosl\n\t"
+
+        /* disable cache */
+        "movl    %cr0, %eax\n\t"
+        "orl    $(0x1<<30),%eax\n\t"
+        "movl    %eax, %cr0\n\t"
+
+        /* enable caching for first 1M using variable mtrr */
+        "movl    $0x200, %ecx\n\t"
+        "xorl    %edx, %edx\n\t"
+        "movl     $(0 | 6), %eax\n\t"
+//	"movl     $(0 | MTRR_TYPE_WRBACK), %eax\n\t"
+        "wrmsr\n\t"
+
+        "movl    $0x201, %ecx\n\t"
+        "movl    $0x0000000f, %edx\n\t" 
+        "movl    $((~(( 0 + 0x100000) - 1)) | 0x800), %eax\n\t"
+        "wrmsr\n\t"
+
+
+        /* enable cache */
+        "movl    %cr0, %eax\n\t"
+        "andl    $0x9fffffff,%eax\n\t"
+        "movl    %eax, %cr0\n\t"
+	"invd\n\t"
+
+        );