erebion/coreboot
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Set the accessed bit on the segment descriptors to prevent writing to them.

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This commit is contained in:
Eric W. Biederman 2001-10-19 18:04:02 +00:00
commit 351efb22d5
1 changed files with 5 additions and 3 deletions
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8
src/cpu/i386/entry16.inc
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@ -39,6 +39,7 @@ EXT(_start): jmp _realstart
/** GDT. we have modified this from the original freebios to make it
* compatible with linux. This puts text at seg 0x10 and data at 0x18
*/
.align 4
.globl EXT(gdtptr)
EXT(gdtptr):
.word 4*8-1
@ -51,10 +52,10 @@ gdt:
.byte 0x0, 0x0, 0x0, 0x0
.word 0xffff, 0x0000 /* flat code segment */
.byte 0x0, 0x9a, 0xcf, 0x0
.byte 0x0, 0x9b, 0xcf, 0x0
.word 0xffff, 0x0000 /* flat data segment */
.byte 0x0, 0x92, 0xcf, 0x0
.byte 0x0, 0x93, 0xcf, 0x0
_realstart:
@ -63,7 +64,7 @@ _realstart:
/* thanks to kmliu@sis.tw.com for this TBL fix ... */
/**/
/* IMMEDIATELY invalidate the translation lookaside buffer before executing*/
/* any further code. Even though paging is we, disabled could still get*/
/* any further code. Even though paging is disabled we could still get*/
/*false address translations due to the TLB if we didn't invalidate it.*/
/**/
xor %eax, %eax
@ -135,3 +136,4 @@ _realstart:
movw %ax, %fs
movw %ax, %gs