/* Written 2000 by Andi Kleen */
#ifndef __ARCH_DESC_DEFS_H
#define __ARCH_DESC_DEFS_H
/*
* Segment descriptor structure definitions, usable from both x86_64 and i386
* archs.
*/
#ifndef __ASSEMBLY__
#include <linux/types.h>
// 8 byte segment descriptor
struct desc_struct {
u16 limit0;
u16 base0;
unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
} __attribute__((packed));
struct n_desc_struct {
unsigned int a,b;
};
enum {
GATE_INTERRUPT = 0xE,
GATE_TRAP = 0xF,
GATE_CALL = 0xC,
};
// 16byte gate
struct gate_struct {
u16 offset_low;
u16 segment;
unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
u16 offset_middle;
u32 offset_high;
u32 zero1;
} __attribute__((packed));
#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF)
#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
#define PTR_HIGH(x) ((unsigned long)(x) >> 32)
enum {
DESC_TSS = 0x9,
DESC_LDT = 0x2,
};
// LDT or TSS descriptor in the GDT. 16 bytes.
struct ldttss_desc {
u16 limit0;
u16 base0;
unsigned base1 : 8, type : 5, dpl : 2, p : 1;
unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
u32 base3;
u32 zero1;
} __attribute__((packed));
struct desc_ptr {
unsigned short size;
unsigned long address;
} __attribute__((packed)) ;
#endif /* !__ASSEMBLY__ */
#endif
