3 #define SEG_TYPE_SYSTEM 0
4 #define SEG_TYPE_CODE 0x00001800
5 #define SEG_TYPE_DATA 0x00001000
6 #define SEG_TYPE_TSS 0x00000100
8 #define SEG_ACCESSED 0x00000100
9 #define SEG_PRESENT 0x00008000
10 #define SEG_AVL 0x00100000
11 #define SEG_GRAN 0x00800000
13 /* data segment type flags */
14 #define SEG_WR 0x00000200
15 #define SEG_EXPDN 0x00000400
16 #define SEG_BIG 0x00400000
17 /* code segment type flags */
18 #define SEG_RD 0x00000200
19 #define SEG_CONFORM 0x00000400
20 #define SEG_DEF 0x00400000
23 #define GATE_TYPE_INTR 0x0e00
24 #define GATE_TYPE_TRAP 0x0f00
25 #define GATE_PRESENT 0x8000
28 void desc_seg(struct desc *desc, int type, uint32_t base, uint32_t limit, int dpl)
30 static uint32_t segtype[] = { 0, SEG_TYPE_CODE, SEG_TYPE_DATA, SEG_TYPE_TSS };
32 if(type == SEG_NULL) {
33 desc->d[0] = desc->d[1] = 0;
37 desc->d[0] = (limit & 0xffff) | (base << 16);
38 desc->d[1] = ((base >> 16) & 0xff) | (type << 8) | SEG_PRESENT | (dpl << 13) | segtype[type];
39 desc->d[1] |= (base & 0xff000000) | (limit & 0xf0000) | SEG_GRAN | SEG_DEF | SEG_RD;
44 void desc_intr(struct desc *desc, int type, uint16_t sel, uint32_t offs, int dpl)
46 uint32_t gate_type[] = { GATE_TYPE_INTR, GATE_TYPE_TRAP };
48 desc->d[0] = (offs & 0xffff) | ((uint32_t)sel << 16);
49 desc->d[1] = (offs & 0xffff0000) | GATE_PRESENT | (dpl << 13) | gate_type[type];