x86: Remove GDR related magic numbers

--
Changes for v2:
 - Use an enum
 - Add defined for GDT size (previously added in patch 7)
 - Use X86_ namespace (as per Linux headers)
This commit is contained in:
Graeme Russ 2011-12-31 10:24:36 +11:00
parent 1176a7067a
commit 109ad143f8
3 changed files with 25 additions and 9 deletions

View file

@ -63,13 +63,13 @@ static void reload_gdt(void)
*/
static const u64 boot_gdt[] __attribute__((aligned(16))) = {
/* CS: code, read/execute, 4 GB, base 0 */
[GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
[X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
/* DS: data, read/write, 4 GB, base 0 */
[GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
[X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
/* 16-bit CS: code, read/execute, 64 kB, base 0 */
[GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
[X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
/* 16-bit DS: data, read/write, 64 kB, base 0 */
[GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
[X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
};
static struct gdt_ptr gdt;

View file

@ -29,6 +29,7 @@
#include <config.h>
#include <version.h>
#include <asm/global_data.h>
#include <asm/processor.h>
#include <asm/processor-flags.h>
#include <generated/asm-offsets.h>
@ -58,7 +59,7 @@ _start:
/* This is the 32-bit cold-reset entry point */
/* Load the segement registes to match the gdt loaded in start16.S */
movl $0x18, %eax
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
movw %ax, %fs
movw %ax, %ds
movw %ax, %gs

View file

@ -24,9 +24,24 @@
#ifndef __ASM_PROCESSOR_H_
#define __ASM_PROCESSOR_H_ 1
#define GDT_ENTRY_32BIT_CS 2
#define GDT_ENTRY_32BIT_DS (GDT_ENTRY_32BIT_CS + 1)
#define GDT_ENTRY_16BIT_CS (GDT_ENTRY_32BIT_DS + 1)
#define GDT_ENTRY_16BIT_DS (GDT_ENTRY_16BIT_CS + 1)
#define X86_GDT_ENTRY_SIZE 8
#ifndef __ASSEMBLY__
enum {
X86_GDT_ENTRY_NULL = 0,
X86_GDT_ENTRY_UNUSED,
X86_GDT_ENTRY_32BIT_CS,
X86_GDT_ENTRY_32BIT_DS,
X86_GDT_ENTRY_16BIT_CS,
X86_GDT_ENTRY_16BIT_DS,
X86_GDT_NUM_ENTRIES
};
#else
/* NOTE: If the above enum is modified, this define must be checked */
#define X86_GDT_ENTRY_32BIT_DS 3
#endif
#define X86_GDT_SIZE (X86_GDT_NUM_ENTRIES * X86_GDT_ENTRY_SIZE)
#endif