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-rw-r--r--src/cpu/x86/pae/pgtbl.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/src/cpu/x86/pae/pgtbl.c b/src/cpu/x86/pae/pgtbl.c
index fe7705f4d0..cd03547ef8 100644
--- a/src/cpu/x86/pae/pgtbl.c
+++ b/src/cpu/x86/pae/pgtbl.c
@@ -144,3 +144,28 @@ void paging_set_pat(uint64_t pat)
msr.hi = pat >> 32;
wrmsr(MSR_IA32_PAT, msr);
}
+
+/* PAT encoding used in util/x86/x86_page_tables.go. It matches the linux
+ * kernel settings:
+ * PTE encoding:
+ * PAT
+ * |PCD
+ * ||PWT PAT
+ * ||| slot
+ * 000 0 WB : _PAGE_CACHE_MODE_WB
+ * 001 1 WC : _PAGE_CACHE_MODE_WC
+ * 010 2 UC-: _PAGE_CACHE_MODE_UC_MINUS
+ * 011 3 UC : _PAGE_CACHE_MODE_UC
+ * 100 4 WB : Reserved
+ * 101 5 WP : _PAGE_CACHE_MODE_WP
+ * 110 6 UC-: Reserved
+ * 111 7 WT : _PAGE_CACHE_MODE_WT
+ */
+void paging_set_default_pat(void)
+{
+ uint64_t pat = PAT_ENCODE(WB, 0) | PAT_ENCODE(WC, 1) |
+ PAT_ENCODE(UC_MINUS, 2) | PAT_ENCODE(UC, 3) |
+ PAT_ENCODE(WB, 4) | PAT_ENCODE(WP, 5) |
+ PAT_ENCODE(UC_MINUS, 6) | PAT_ENCODE(WT, 7);
+ paging_set_pat(pat);
+}