global.h

#ifndef _KERNEL_CLOBAL_H
#define _KERNEL_CLOBAL_H
#include "stdint.h"

#define RPL0 0
#define RPL1 1
#define RPL2 2
#define RPL3 3
#define DESC_G_4k 1
#define DESC_D_32 1
#define DESC_L 0
#define DESC_AVL 0
#define DESC_P 1
#define DESC_DPL_0 0
#define DESC_DPL_1 1
#define DESC_DPL_2 2
#define DESC_DPL_3 3
//代码段
#define DESC_S_CODE 1
#define DESC_S_DATA 1
//系统段
#define DESC_S_SYS 0
#define DESC_TYPE_CODE 8 //1000可执行，不可读
#define DESC_TYPE_DATA 2 //0010不可执行，可写，向上扩展的

#define DESC_TYPE_TSS 9//1001 tss属性，b位为0-不忙

#define TI_GDT 0
#define TI_LDT 1

#define SELECTOR_K_CODE ((1<<3) + (TI_GDT << 2) + RPL0)
#define SEELCTOR_K_DATA ((2<<3) + (TI_GDT << 2) + RPL0)
#define SELECTOR_K_STACK  SEELCTOR_K_DATA
//显存段选择子
#define SELECTOR_K_GS ((3<<3) + (TI_GDT << 2) + RPL0)
//用户代码段选择子,tss占据第4给选择子
#define SELECTOR_U_CODE ((5<<3) + (TI_GDT << 2) + RPL3)
#define SELECTOR_U_DATA ((6<<3) + (TI_GDT << 2) + RPL3)
#define SELECTOR_U_STACK SELECTOR_U_DATA
#define GDT_ATTR_HIGH \
     ((DESC_G_4k << 7) + (DESC_D_32 << 6)+(DESC_L << 5) + (DESC_AVL << 4))

#define GDT_CODE_ATTR_LOW_DPL3 \
((DESC_P << 7) + (DESC_DPL_3 << 5) + (DESC_S_CODE << 4) + (DESC_TYPE_CODE))

#define GDT_DATA_ATTR_LOW_DPL3 \
((DESC_P << 7) + (DESC_DPL_3 << 5) + (DESC_S_DATA << 4) + (DESC_TYPE_DATA))

#define TSS_DESC_D 0

#define TSS_ATTR_HIGH \
((DESC_G_4k << 7) + (DESC_D_32 << 6)+(DESC_L << 5) + (DESC_AVL << 4) + 0x0)

#define TSS_ATTR_LOW \
((DESC_P << 7) + (DESC_DPL_0 << 5) + (DESC_S_SYS << 4) + (DESC_TYPE_TSS))

#define SELECTOR_TSS ((4<<3) + (TI_GDT << 2) + RPL0)

#define IDT_DESC_P 1
#define IDT_DESC_DPL0 0
#define IDT_DESC_DPL3 3
#define IDT_DESC_32_TYPE 0xe
#define IDT_DESC_16_TYPE 0x6

#define IDT_DESC_ATTR_DPL0 ((IDT_DESC_P << 7) + (IDT_DESC_DPL0 << 5) + (IDT_DESC_32_TYPE))
#define IDT_DESC_ATTR_DPL3 ((IDT_DESC_P << 7) + (IDT_DESC_DPL3 << 5) + (IDT_DESC_32_TYPE))

#define EFLAGS_MBS (1<<1)
#define EFLAGS_IF_1 (1<<9)
#define EFLAGS_IF_0 0
#define EFLAGS_IOPL_3 (3<<12)
#define EFLAGS_IOPL_0 (0<<12)

#define DIV_ROUND_UP(x,step) ((x+step-1)/step)

#define NULL ((void*)0)
#define bool int
#define false 0
#define true 1
#define UNUSED __attribute__ ((unused))

struct gdt_desc{
	uint16_t limit_low_word;
	uint16_t base_low_word;
	uint8_t base_mid_byte;
	uint8_t attr_low_byte;
	uint8_t limit_high_attr_high;//将属性和界限合并
	uint8_t base_high_byte;
};

#endif