5
* The layout of the per-CPU GDT under Linux:
12
* 4 - unused <==== new cacheline
15
* ------- start of TLS (Thread-Local Storage) segments:
17
* 6 - TLS segment #1 [ glibc's TLS segment ]
18
* 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
24
* ------- start of kernel segments:
26
* 12 - kernel code segment <==== new cacheline
27
* 13 - kernel data segment
28
* 14 - default user CS
29
* 15 - default user DS
32
* 18 - PNPBIOS support (16->32 gate)
33
* 19 - PNPBIOS support
34
* 20 - PNPBIOS support
35
* 21 - PNPBIOS support
36
* 22 - PNPBIOS support
37
* 23 - APM BIOS support
38
* 24 - APM BIOS support
39
* 25 - APM BIOS support
41
* 26 - ESPFIX small SS
46
* 31 - TSS for double fault handler
48
#define GDT_ENTRY_TLS_ENTRIES 3
49
#define GDT_ENTRY_TLS_MIN 6
50
#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
52
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)
54
#define GDT_ENTRY_DEFAULT_USER_CS 14
55
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS * 8 + 3)
57
#define GDT_ENTRY_DEFAULT_USER_DS 15
58
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS * 8 + 3)
60
#define GDT_ENTRY_KERNEL_BASE 12
62
#define GDT_ENTRY_KERNEL_CS (GDT_ENTRY_KERNEL_BASE + 0)
63
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS * 8)
65
#define GDT_ENTRY_KERNEL_DS (GDT_ENTRY_KERNEL_BASE + 1)
66
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS * 8)
68
#define GDT_ENTRY_TSS (GDT_ENTRY_KERNEL_BASE + 4)
69
#define GDT_ENTRY_LDT (GDT_ENTRY_KERNEL_BASE + 5)
71
#define GDT_ENTRY_PNPBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 6)
72
#define GDT_ENTRY_APMBIOS_BASE (GDT_ENTRY_KERNEL_BASE + 11)
74
#define GDT_ENTRY_ESPFIX_SS (GDT_ENTRY_KERNEL_BASE + 14)
75
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS * 8)
77
#define GDT_ENTRY_DOUBLEFAULT_TSS 31
80
* The GDT has 32 entries
82
#define GDT_ENTRIES 32
84
#define GDT_SIZE (GDT_ENTRIES * 8)
86
/* Simple and small GDT entries for booting only */
88
#define GDT_ENTRY_BOOT_CS 2
89
#define __BOOT_CS (GDT_ENTRY_BOOT_CS * 8)
91
#define GDT_ENTRY_BOOT_DS (GDT_ENTRY_BOOT_CS + 1)
92
#define __BOOT_DS (GDT_ENTRY_BOOT_DS * 8)
95
* The interrupt descriptor table has room for 256 idt's,
96
* the global descriptor table is dependent on the number
97
* of tasks we can have..
99
#define IDT_ENTRIES 256