aha/include/asm-i386/segment.h
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

101 lines
2.4 KiB
C

#ifndef _ASM_SEGMENT_H
#define _ASM_SEGMENT_H
/*
* The layout of the per-CPU GDT under Linux:
*
* 0 - null
* 1 - reserved
* 2 - reserved
* 3 - reserved
*
* 4 - unused <==== new cacheline
* 5 - unused
*
* ------- start of TLS (Thread-Local Storage) segments:
*
* 6 - TLS segment #1 [ glibc's TLS segment ]
* 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
* 8 - TLS segment #3
* 9 - reserved
* 10 - reserved
* 11 - reserved
*
* ------- start of kernel segments:
*
* 12 - kernel code segment <==== new cacheline
* 13 - kernel data segment
* 14 - default user CS
* 15 - default user DS
* 16 - TSS
* 17 - LDT
* 18 - PNPBIOS support (16->32 gate)
* 19 - PNPBIOS support
* 20 - PNPBIOS support
* 21 - PNPBIOS support
* 22 - PNPBIOS support
* 23 - APM BIOS support
* 24 - APM BIOS support
* 25 - APM BIOS support
*
* 26 - ESPFIX small SS
* 27 - unused
* 28 - unused
* 29 - unused
* 30 - unused
* 31 - TSS for double fault handler
*/
#define GDT_ENTRY_TLS_ENTRIES 3
#define GDT_ENTRY_TLS_MIN 6
#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
#define GDT_ENTRY_DEFAULT_USER_CS 14
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS * 8 + 3)
#define GDT_ENTRY_DEFAULT_USER_DS 15
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS * 8 + 3)
#define GDT_ENTRY_KERNEL_BASE 12
#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0)
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8)
#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1)
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8)
#define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE + 4)
#define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE + 5)
#define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 6)
#define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 11)
#define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14)
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)
#define GDT_ENTRY_DOUBLEFAULT_TSS 31
/*
* The GDT has 32 entries
*/
#define GDT_ENTRIES 32
#define GDT_SIZE (GDT_ENTRIES * 8)
/* Simple and small GDT entries for booting only */
#define GDT_ENTRY_BOOT_CS 2
#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8)
#define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1)
#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8)
/*
* The interrupt descriptor table has room for 256 idt's,
* the global descriptor table is dependent on the number
* of tasks we can have..
*/
#define IDT_ENTRIES 256
#endif