Module Name: src
Committed By: jym
Date: Sun Apr 18 15:24:54 UTC 2010
Modified Files:
src/sys/arch/amd64/amd64: locore.S
Log Message:
When kernel remaps to high memory in amd64 locore, the GDT used before
becomes invalid. As such, split it in two parts, one for use when system
boots in low memory, and one for use when it jumps to high memory.
To generate a diff of this commit:
cvs rdiff -u -r1.55 -r1.56 src/sys/arch/amd64/amd64/locore.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/locore.S
diff -u src/sys/arch/amd64/amd64/locore.S:1.55 src/sys/arch/amd64/amd64/locore.S:1.56
--- src/sys/arch/amd64/amd64/locore.S:1.55 Fri Nov 27 03:23:04 2009
+++ src/sys/arch/amd64/amd64/locore.S Sun Apr 18 15:24:54 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.S,v 1.55 2009/11/27 03:23:04 rmind Exp $ */
+/* $NetBSD: locore.S,v 1.56 2010/04/18 15:24:54 jym Exp $ */
/*
* Copyright-o-rama!
@@ -269,13 +269,25 @@
#define RELOC(x) _RELOC(_C_LABEL(x))
#ifndef XEN
- .globl gdt64
+ .globl gdt64_lo
+ .globl gdt64_hi
-gdt64:
- .word gdt64_end-gdt64_start
+#define GDT64_LIMIT gdt64_end-gdt64_start-1
+
+/* Temporary gdt64, with base address in low memory */
+gdt64_lo:
+ .word GDT64_LIMIT
.quad _RELOC(gdt64_start)
.align 64
+/* Temporary gdt64, with base address in high memory */
+gdt64_hi:
+ .word GDT64_LIMIT
+ .quad gdt64_start
+.align 64
+
+#undef GDT64_LIMIT
+
gdt64_start:
.quad 0x0000000000000000 /* always empty */
.quad 0x00af9a000000ffff /* kernel CS */
@@ -638,7 +650,7 @@
* in it to do that.
*/
- movl $RELOC(gdt64),%eax
+ movl $RELOC(gdt64_lo),%eax
lgdt (%eax)
movl $RELOC(farjmp64),%eax
ljmp *(%eax)
@@ -654,9 +666,17 @@
*/
movabsq $longmode_hi,%rax
jmp *%rax
+
longmode_hi:
+
+ /*
+ * We left the identity mapped area. Base address of
+ * the temporary gdt64 should now be in high memory.
+ */
+ movq $RELOC(gdt64_hi),%rax
+ lgdt (%rax)
+
/*
- * We have arrived.
* There's no need anymore for the identity mapping in low
* memory, remove it.
*/
