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day6分割编译与中断处理 ​

bash
..\z_tools\make.exe %1 %2 %3 %4 %5 %6 %7 %8 %9

make.bat, 使用make命令的时候实际上实行的命令

c
/* bootpackのメイン */

#include <stdio.h>

void io_hlt(void);
void io_cli(void);
void io_out8(int port, int data);
int io_load_eflags(void);
void io_store_eflags(int eflags);

void init_palette(void);
void set_palette(int start, int end, unsigned char *rgb);
void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1);
void init_screen8(char *vram, int x, int y);
void putfont8(char *vram, int xsize, int x, int y, char c, char *font);
void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s);
void init_mouse_cursor8(char *mouse, char bc);
void putblock8_8(char *vram, int vxsize, int pxsize,
	int pysize, int px0, int py0, char *buf, int bxsize);

#define COL8_000000		0
#define COL8_FF0000		1
#define COL8_00FF00		2
#define COL8_FFFF00		3
#define COL8_0000FF		4
#define COL8_FF00FF		5
#define COL8_00FFFF		6
#define COL8_FFFFFF		7
#define COL8_C6C6C6		8
#define COL8_840000		9
#define COL8_008400		10
#define COL8_848400		11
#define COL8_000084		12
#define COL8_840084		13
#define COL8_008484		14
#define COL8_848484		15
//这里是自己保存的内容
struct BOOTINFO {
	char cyls, leds, vmode, reserve;
	short scrnx, scrny;
	char *vram;
};
//GDT
struct SEGMENT_DESCRIPTOR {
	short limit_low, base_low;
	char base_mid, access_right;
	char limit_high, base_high;
};
//IDT
struct GATE_DESCRIPTOR {
	short offset_low, selector;
	char dw_count, access_right;
	short offset_high;
};
//其他文件的函数
void init_gdtidt(void);
void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar);
void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar);
void load_gdtr(int limit, int addr);
void load_idtr(int limit, int addr);

void HariMain(void)
{
	struct BOOTINFO *binfo = (struct BOOTINFO *) 0x0ff0;
	char s[40], mcursor[256];
	int mx, my;

	init_gdtidt();
	init_palette();
	init_screen8(binfo->vram, binfo->scrnx, binfo->scrny);
	mx = (binfo->scrnx - 16) / 2; /* 计算鼠标的位置 */
	my = (binfo->scrny - 28 - 16) / 2;
	init_mouse_cursor8(mcursor, COL8_008484);
	putblock8_8(binfo->vram, binfo->scrnx, 16, 16, mx, my, mcursor, 16);
	sprintf(s, "(%d, %d)", mx, my);
	putfonts8_asc(binfo->vram, binfo->scrnx, 0, 0, COL8_FFFFFF, s);

	for (;;) {
		io_hlt();
	}
}

bootpack.c

c
/* 使用的结构体 */

struct SEGMENT_DESCRIPTOR {
	short limit_low, base_low;
	char base_mid, access_right;
	char limit_high, base_high;
};

struct GATE_DESCRIPTOR {
	short offset_low, selector;
	char dw_count, access_right;
	short offset_high;
};

void init_gdtidt(void);
void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar);
void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar);
void load_gdtr(int limit, int addr);
void load_idtr(int limit, int addr);
//初始化
void init_gdtidt(void)
{
	struct SEGMENT_DESCRIPTOR *gdt = (struct SEGMENT_DESCRIPTOR *) 0x00270000;
	struct GATE_DESCRIPTOR    *idt = (struct GATE_DESCRIPTOR    *) 0x0026f800;
	int i;

	/* GDT初始化 */
	for (i = 0; i < 8192; i++) {
		set_segmdesc(gdt + i, 0, 0, 0);
	}
	set_segmdesc(gdt + 1, 0xffffffff, 0x00000000, 0x4092);
	set_segmdesc(gdt + 2, 0x0007ffff, 0x00280000, 0x409a);
	load_gdtr(0xffff, 0x00270000);

	/* IDT初始化 */
	for (i = 0; i < 256; i++) {
		set_gatedesc(idt + i, 0, 0, 0);
	}
	load_idtr(0x7ff, 0x0026f800);

	return;
}

void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar)
{
	if (limit > 0xfffff) {
		ar |= 0x8000; /* G_bit = 1 */
		limit /= 0x1000;
	}
	sd->limit_low    = limit & 0xffff;
	sd->base_low     = base & 0xffff;
	sd->base_mid     = (base >> 16) & 0xff;
	sd->access_right = ar & 0xff;
	sd->limit_high   = ((limit >> 16) & 0x0f) | ((ar >> 8) & 0xf0);
	sd->base_high    = (base >> 24) & 0xff;
	return;
}

void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar)
{
	gd->offset_low   = offset & 0xffff;
	gd->selector     = selector;
	gd->dw_count     = (ar >> 8) & 0xff;
	gd->access_right = ar & 0xff;
	gd->offset_high  = (offset >> 16) & 0xffff;
	return;
}

dsctbl.c

c
/* 图形处理 */

void io_hlt(void);
void io_cli(void);
void io_out8(int port, int data);
int io_load_eflags(void);
void io_store_eflags(int eflags);

void init_palette(void);
void set_palette(int start, int end, unsigned char *rgb);
void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1);
void init_screen8(char *vram, int x, int y);
void putfont8(char *vram, int xsize, int x, int y, char c, char *font);
void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s);
void init_mouse_cursor8(char *mouse, char bc);
void putblock8_8(char *vram, int vxsize, int pxsize,
	int pysize, int px0, int py0, char *buf, int bxsize);

#define COL8_000000		0
#define COL8_FF0000		1
#define COL8_00FF00		2
#define COL8_FFFF00		3
#define COL8_0000FF		4
#define COL8_FF00FF		5
#define COL8_00FFFF		6
#define COL8_FFFFFF		7
#define COL8_C6C6C6		8
#define COL8_840000		9
#define COL8_008400		10
#define COL8_848400		11
#define COL8_000084		12
#define COL8_840084		13
#define COL8_008484		14
#define COL8_848484		15

void init_palette(void)
{
	static unsigned char table_rgb[16 * 3] = {
		0x00, 0x00, 0x00,	/*  0:黒 */
		0xff, 0x00, 0x00,	/*  1:明るい赤 */
		0x00, 0xff, 0x00,	/*  2:明るい緑 */
		0xff, 0xff, 0x00,	/*  3:明るい黄色 */
		0x00, 0x00, 0xff,	/*  4:明るい青 */
		0xff, 0x00, 0xff,	/*  5:明るい紫 */
		0x00, 0xff, 0xff,	/*  6:明るい水色 */
		0xff, 0xff, 0xff,	/*  7:白 */
		0xc6, 0xc6, 0xc6,	/*  8:明るい灰色 */
		0x84, 0x00, 0x00,	/*  9:暗い赤 */
		0x00, 0x84, 0x00,	/* 10:暗い緑 */
		0x84, 0x84, 0x00,	/* 11:暗い黄色 */
		0x00, 0x00, 0x84,	/* 12:暗い青 */
		0x84, 0x00, 0x84,	/* 13:暗い紫 */
		0x00, 0x84, 0x84,	/* 14:暗い水色 */
		0x84, 0x84, 0x84	/* 15:暗い灰色 */
	};
	set_palette(0, 15, table_rgb);
	return;

	/* static char 命令は、データにしか使えないけどDB命令相当 */
}
//设置调色盘
void set_palette(int start, int end, unsigned char *rgb)
{
	int i, eflags;
	eflags = io_load_eflags();	
	io_cli(); 					
	io_out8(0x03c8, start);
	for (i = start; i <= end; i++) {
		io_out8(0x03c9, rgb[0] / 4);
		io_out8(0x03c9, rgb[1] / 4);
		io_out8(0x03c9, rgb[2] / 4);
		rgb += 3;
	}
	io_store_eflags(eflags);	
	return;
}

void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1)
{
	int x, y;
	for (y = y0; y <= y1; y++) {
		for (x = x0; x <= x1; x++)
			vram[y * xsize + x] = c;
	}
	return;
}
//绘制桌面
void init_screen8(char *vram, int x, int y)
{
	boxfill8(vram, x, COL8_008484,  0,     0,      x -  1, y - 29);
	boxfill8(vram, x, COL8_C6C6C6,  0,     y - 28, x -  1, y - 28);
	boxfill8(vram, x, COL8_FFFFFF,  0,     y - 27, x -  1, y - 27);
	boxfill8(vram, x, COL8_C6C6C6,  0,     y - 26, x -  1, y -  1);

	boxfill8(vram, x, COL8_FFFFFF,  3,     y - 24, 59,     y - 24);
	boxfill8(vram, x, COL8_FFFFFF,  2,     y - 24,  2,     y -  4);
	boxfill8(vram, x, COL8_848484,  3,     y -  4, 59,     y -  4);
	boxfill8(vram, x, COL8_848484, 59,     y - 23, 59,     y -  5);
	boxfill8(vram, x, COL8_000000,  2,     y -  3, 59,     y -  3);
	boxfill8(vram, x, COL8_000000, 60,     y - 24, 60,     y -  3);

	boxfill8(vram, x, COL8_848484, x - 47, y - 24, x -  4, y - 24);
	boxfill8(vram, x, COL8_848484, x - 47, y - 23, x - 47, y -  4);
	boxfill8(vram, x, COL8_FFFFFF, x - 47, y -  3, x -  4, y -  3);
	boxfill8(vram, x, COL8_FFFFFF, x -  3, y - 24, x -  3, y -  3);
	return;
}

void putfont8(char *vram, int xsize, int x, int y, char c, char *font)
{
	int i;
	char *p, d /* data */;
	for (i = 0; i < 16; i++) {
		p = vram + (y + i) * xsize + x;
		d = font[i];
		if ((d & 0x80) != 0) { p[0] = c; }
		if ((d & 0x40) != 0) { p[1] = c; }
		if ((d & 0x20) != 0) { p[2] = c; }
		if ((d & 0x10) != 0) { p[3] = c; }
		if ((d & 0x08) != 0) { p[4] = c; }
		if ((d & 0x04) != 0) { p[5] = c; }
		if ((d & 0x02) != 0) { p[6] = c; }
		if ((d & 0x01) != 0) { p[7] = c; }
	}
	return;
}
//这里是打印一个字
void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s)
{
	extern char hankaku[4096];
	for (; *s != 0x00; s++) {
		putfont8(vram, xsize, x, y, c, hankaku + *s * 16);
		x += 8;
	}
	return;
}

void init_mouse_cursor8(char *mouse, char bc)
/* 这是鼠标结构体初始化 */
{
	static char cursor[16][16] = {
		"**************..",
		"*OOOOOOOOOOO*...",
		"*OOOOOOOOOO*....",
		"*OOOOOOOOO*.....",
		"*OOOOOOOO*......",
		"*OOOOOOO*.......",
		"*OOOOOOO*.......",
		"*OOOOOOOO*......",
		"*OOOO**OOO*.....",
		"*OOO*..*OOO*....",
		"*OO*....*OOO*...",
		"*O*......*OOO*..",
		"**........*OOO*.",
		"*..........*OOO*",
		"............*OO*",
		".............***"
	};
	int x, y;

	for (y = 0; y < 16; y++) {
		for (x = 0; x < 16; x++) {
			if (cursor[y][x] == '*') {
				mouse[y * 16 + x] = COL8_000000;
			}
			if (cursor[y][x] == 'O') {
				mouse[y * 16 + x] = COL8_FFFFFF;
			}
			if (cursor[y][x] == '.') {
				mouse[y * 16 + x] = bc;
			}
		}
	}
	return;
}
//绘制鼠标
void putblock8_8(char *vram, int vxsize, int pxsize,
	int pysize, int px0, int py0, char *buf, int bxsize)
{
	int x, y;
	for (y = 0; y < pysize; y++) {
		for (x = 0; x < pxsize; x++) {
			vram[(py0 + y) * vxsize + (px0 + x)] = buf[y * bxsize + x];
		}
	}
	return;
}

graphic.c

makefile
TOOLPATH = ../z_tools/
INCPATH  = ../z_tools/haribote/

MAKE     = $(TOOLPATH)make.exe -r
NASK     = $(TOOLPATH)nask.exe
CC1      = $(TOOLPATH)cc1.exe -I$(INCPATH) -Os -Wall -quiet
GAS2NASK = $(TOOLPATH)gas2nask.exe -a
OBJ2BIM  = $(TOOLPATH)obj2bim.exe
MAKEFONT = $(TOOLPATH)makefont.exe
BIN2OBJ  = $(TOOLPATH)bin2obj.exe
BIM2HRB  = $(TOOLPATH)bim2hrb.exe
RULEFILE = $(TOOLPATH)haribote/haribote.rul
EDIMG    = $(TOOLPATH)edimg.exe
IMGTOL   = $(TOOLPATH)imgtol.com
COPY     = copy
DEL      = del

# 默认

default :
	$(MAKE) img

# 生成规则
# 汇编文件
ipl10.bin : ipl10.nas Makefile
	$(NASK) ipl10.nas ipl10.bin ipl10.lst

asmhead.bin : asmhead.nas Makefile
	$(NASK) asmhead.nas asmhead.bin asmhead.lst
# 这里是c文件
bootpack.gas : bootpack.c Makefile
	$(CC1) -o bootpack.gas bootpack.c

bootpack.nas : bootpack.gas Makefile
	$(GAS2NASK) bootpack.gas bootpack.nas

bootpack.obj : bootpack.nas Makefile
	$(NASK) bootpack.nas bootpack.obj bootpack.lst
# 另一个汇编
naskfunc.obj : naskfunc.nas Makefile
	$(NASK) naskfunc.nas naskfunc.obj naskfunc.lst
# 字库文件
hankaku.bin : hankaku.txt Makefile
	$(MAKEFONT) hankaku.txt hankaku.bin

hankaku.obj : hankaku.bin Makefile
	$(BIN2OBJ) hankaku.bin hankaku.obj _hankaku
# 绘图c文件
graphic.gas : graphic.c Makefile
	$(CC1) -o graphic.gas graphic.c

graphic.nas : graphic.gas Makefile
	$(GAS2NASK) graphic.gas graphic.nas

graphic.obj : graphic.nas Makefile
	$(NASK) graphic.nas graphic.obj graphic.lst

dsctbl.gas : dsctbl.c Makefile
	$(CC1) -o dsctbl.gas dsctbl.c

dsctbl.nas : dsctbl.gas Makefile
	$(GAS2NASK) dsctbl.gas dsctbl.nas

dsctbl.obj : dsctbl.nas Makefile
	$(NASK) dsctbl.nas dsctbl.obj dsctbl.lst
# 链接
bootpack.bim : bootpack.obj naskfunc.obj hankaku.obj graphic.obj dsctbl.obj Makefile
	$(OBJ2BIM) @$(RULEFILE) out:bootpack.bim stack:3136k map:bootpack.map \
		bootpack.obj naskfunc.obj hankaku.obj graphic.obj dsctbl.obj
# 3MB+64KB=3136KB

bootpack.hrb : bootpack.bim Makefile
	$(BIM2HRB) bootpack.bim bootpack.hrb 0

haribote.sys : asmhead.bin bootpack.hrb Makefile
	copy /B asmhead.bin+bootpack.hrb haribote.sys

haribote.img : ipl10.bin haribote.sys Makefile
	$(EDIMG)   imgin:../z_tools/fdimg0at.tek \
		wbinimg src:ipl10.bin len:512 from:0 to:0 \
		copy from:haribote.sys to:@: \
		imgout:haribote.img

# 命令

img :
	$(MAKE) haribote.img

run :
	$(MAKE) img
	$(COPY) haribote.img ..\z_tools\qemu\fdimage0.bin
	$(MAKE) -C ../z_tools/qemu

install :
	$(MAKE) img
	$(IMGTOL) w a: haribote.img

clean :
	-$(DEL) *.bin
	-$(DEL) *.lst
	-$(DEL) *.gas
	-$(DEL) *.obj
	-$(DEL) bootpack.nas
	-$(DEL) graphic.nas
	-$(DEL) dsctbl.nas
	-$(DEL) bootpack.map
	-$(DEL) bootpack.bim
	-$(DEL) bootpack.hrb
	-$(DEL) haribote.sys

src_only :
	$(MAKE) clean
	-$(DEL) haribote.img

Makefile简化 ​

makefile
# 所需要的所有文件
OBJS_BOOTPACK = bootpack.obj naskfunc.obj hankaku.obj graphic.obj dsctbl.obj

TOOLPATH = ../z_tools/
INCPATH  = ../z_tools/haribote/

MAKE     = $(TOOLPATH)make.exe -r
NASK     = $(TOOLPATH)nask.exe
CC1      = $(TOOLPATH)cc1.exe -I$(INCPATH) -Os -Wall -quiet
GAS2NASK = $(TOOLPATH)gas2nask.exe -a
OBJ2BIM  = $(TOOLPATH)obj2bim.exe
MAKEFONT = $(TOOLPATH)makefont.exe
BIN2OBJ  = $(TOOLPATH)bin2obj.exe
BIM2HRB  = $(TOOLPATH)bim2hrb.exe
RULEFILE = $(TOOLPATH)haribote/haribote.rul
EDIMG    = $(TOOLPATH)edimg.exe
IMGTOL   = $(TOOLPATH)imgtol.com
COPY     = copy
DEL      = del

# デフォルト動作

default :
	$(MAKE) img

# ファイル生成規則
# 启动文件
ipl10.bin : ipl10.nas Makefile
	$(NASK) ipl10.nas ipl10.bin ipl10.lst

asmhead.bin : asmhead.nas Makefile
	$(NASK) asmhead.nas asmhead.bin asmhead.lst
# 生成字摸文件
hankaku.bin : hankaku.txt Makefile
	$(MAKEFONT) hankaku.txt hankaku.bin

hankaku.obj : hankaku.bin Makefile
	$(BIN2OBJ) hankaku.bin hankaku.obj _hankaku

bootpack.bim : $(OBJS_BOOTPACK) Makefile
	$(OBJ2BIM) @$(RULEFILE) out:bootpack.bim stack:3136k map:bootpack.map \
		$(OBJS_BOOTPACK)
# 3MB+64KB=3136KB

bootpack.hrb : bootpack.bim Makefile
	$(BIM2HRB) bootpack.bim bootpack.hrb 0

haribote.sys : asmhead.bin bootpack.hrb Makefile
	copy /B asmhead.bin+bootpack.hrb haribote.sys

haribote.img : ipl10.bin haribote.sys Makefile
	$(EDIMG)   imgin:../z_tools/fdimg0at.tek \
		wbinimg src:ipl10.bin len:512 from:0 to:0 \
		copy from:haribote.sys to:@: \
		imgout:haribote.img

# 一般規則

%.gas : %.c Makefile
	$(CC1) -o $*.gas $*.c

%.nas : %.gas Makefile
	$(GAS2NASK) $*.gas $*.nas

%.obj : %.nas Makefile
	$(NASK) $*.nas $*.obj $*.lst

# 实际命令

img :
	$(MAKE) haribote.img

run :
	$(MAKE) img
	$(COPY) haribote.img ..\z_tools\qemu\fdimage0.bin
	$(MAKE) -C ../z_tools/qemu

install :
	$(MAKE) img
	$(IMGTOL) w a: haribote.img

clean :
	-$(DEL) *.bin
	-$(DEL) *.lst
	-$(DEL) *.obj
	-$(DEL) bootpack.map
	-$(DEL) bootpack.bim
	-$(DEL) bootpack.hrb
	-$(DEL) haribote.sys

src_only :
	$(MAKE) clean
	-$(DEL) haribote.img
  • 把重复的声明放在一个头文件中
c
/* asmhead.nas */
struct BOOTINFO { /* 0x0ff0-0x0fff */
	char cyls; /* 启动区的硬盘读取到何处 */
	char leds; /* 键盘指示灯的状态 */
	char vmode; /* 显卡的模式 */
	char reserve;
	short scrnx, scrny; /* 画面分辨率 */
	char *vram;
};
#define ADR_BOOTINFO	0x00000ff0

/* naskfunc.nas */
void io_hlt(void);
void io_cli(void);
void io_out8(int port, int data);
int io_load_eflags(void);
void io_store_eflags(int eflags);
void load_gdtr(int limit, int addr);
void load_idtr(int limit, int addr);

/* graphic.c 画面相关的函数*/
void init_palette(void);
void set_palette(int start, int end, unsigned char *rgb);
void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, int x1, int y1);
void init_screen8(char *vram, int x, int y);
void putfont8(char *vram, int xsize, int x, int y, char c, char *font);
void putfonts8_asc(char *vram, int xsize, int x, int y, char c, unsigned char *s);
void init_mouse_cursor8(char *mouse, char bc);
void putblock8_8(char *vram, int vxsize, int pxsize,
	int pysize, int px0, int py0, char *buf, int bxsize);
#define COL8_000000		0
#define COL8_FF0000		1
#define COL8_00FF00		2
#define COL8_FFFF00		3
#define COL8_0000FF		4
#define COL8_FF00FF		5
#define COL8_00FFFF		6
#define COL8_FFFFFF		7
#define COL8_C6C6C6		8
#define COL8_840000		9
#define COL8_008400		10
#define COL8_848400		11
#define COL8_000084		12
#define COL8_840084		13
#define COL8_008484		14
#define COL8_848484		15

/* dsctbl.c */
struct SEGMENT_DESCRIPTOR {
	short limit_low, base_low;
	char base_mid, access_right;
	char limit_high, base_high;
};
struct GATE_DESCRIPTOR {
	short offset_low, selector;
	char dw_count, access_right;
	short offset_high;
};
void init_gdtidt(void);
void set_segmdesc(struct SEGMENT_DESCRIPTOR *sd, unsigned int limit, int base, int ar);
void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar);
#define ADR_IDT			0x0026f800		//IDT
#define LIMIT_IDT		0x000007ff
#define ADR_GDT			0x00270000		//GDT
#define LIMIT_GDT		0x0000ffff
#define ADR_BOTPAK		0x00280000		//bootpack文件起始位置
#define LIMIT_BOTPAK	0x0007ffff 		//??文件大小
#define AR_DATA32_RW	0x4092
#define AR_CODE32_ER	0x409a

放在文件bootpack.h文件里面

中断处理器PIC ​

PIC(programmable interrupt controller), 可编程中断控制器

CPU只能处理一个中断, PIC将八个中断汇集成一个中断, 每一个管脚是一个IRQ, IRQ2连接从PIC

主PIC处理0-7, 从PIC处理8-15

c
/* 割り込み関係 */

#include "bootpack.h"

#define PIC0_ICW1		0x0020
#define PIC0_OCW2		0x0020
#define PIC0_IMR		0x0021
#define PIC0_ICW2		0x0021
#define PIC0_ICW3		0x0021
#define PIC0_ICW4		0x0021
#define PIC1_ICW1		0x00a0
#define PIC1_OCW2		0x00a0
#define PIC1_IMR		0x00a1
#define PIC1_ICW2		0x00a1
#define PIC1_ICW3		0x00a1
#define PIC1_ICW4		0x00a1

void init_pic(void)
/* PICの初期化 */
{
    //外部的设备使用out命令进行操作
	io_out8(PIC0_IMR,  0xff  ); /* 禁止所有的中断 */
	io_out8(PIC1_IMR,  0xff  ); /* 禁止所有的中断 */

	io_out8(PIC0_ICW1, 0x11  ); /* 边沿触发模式 */
	io_out8(PIC0_ICW2, 0x20  ); /* IRQ0-7由INT20-27接受 */
	io_out8(PIC0_ICW3, 1 << 2); /* PIC1由IRQ2连接 */
	io_out8(PIC0_ICW4, 0x01  ); /* 无缓冲区模式 */

	io_out8(PIC1_ICW1, 0x11  ); /* 边沿触发 */
	io_out8(PIC1_ICW2, 0x28  ); /* IRQ8-15由INT28-2f接收 */
	io_out8(PIC1_ICW3, 2     ); /* PIC由IRQ2连接 */
	io_out8(PIC1_ICW4, 0x01  ); /* 无缓冲区模式 */

	io_out8(PIC0_IMR,  0xfb  ); /* 11111011 PIC1以外全部禁止 */
	io_out8(PIC1_IMR,  0xff  ); /* 11111111 禁止所有中断 */

	return;
}

PIC寄存器都是8位寄存器

IMR(interrupt mask register)是中断屏蔽寄存器, 对应8路的信号

ICW(interrupt control word)初始化控制数据

ICW1, ICW4表示的是PIC的主板配线, 中断信号, 电气特性, 不能更改

ICW3设置的是主从连接的方式, 硬件控制

ICW2, 决定了通知CPU的中断

  • 如果CPU可以处理某一个中断, 会命令PIC发送两个字节, 发送过来的数字是0xcd 0x??, 0xcd实际上就是调用BOIS的时候使用的INT指令, CPU会当做指令直接执行
  • INT指令的前几个已经被使用了, 所以不能使用

鼠标的中断是IRQ12, 键盘的中断是IQ1

c
void inthandler21(int *esp)
/* 键盘的中断 */
{
	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
	boxfill8(binfo->vram, binfo->scrnx, COL8_000000, 0, 0, 32 * 8 - 1, 15);  
	putfonts8_asc(binfo->vram, binfo->scrnx, 0, 0, COL8_FFFFFF, "INT 21 (IRQ-1) : PS/2 keyboard");
	for (;;) {
		io_hlt();
	}
}

void inthandler2c(int *esp)
/* PS/2マウスからの割り込み */
{
	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
	boxfill8(binfo->vram, binfo->scrnx, COL8_000000, 0, 0, 32 * 8 - 1, 15);
	putfonts8_asc(binfo->vram, binfo->scrnx, 0, 0, COL8_FFFFFF, "INT 2C (IRQ-12) : PS/2 mouse");
	for (;;) {
		io_hlt();
	}
}

void inthandler27(int *esp)
/*有的机器在初始化PIC的时候会产生这个中断*/
{
	io_out8(PIC0_OCW2, 0x67); /* 通知PIC已经知道发生中断了 */
	return;
}

中断处理之后需要执行IRETD指令

assembly
_asm_inthandler21:
		PUSH	ES
		PUSH	DS
		PUSHAD
		MOV		EAX,ESP
		PUSH	EAX
		MOV		AX,SS
		MOV		DS,AX
		MOV		ES,AX
		CALL	_inthandler21
		POP		EAX
		POPAD
		POP		DS
		POP		ES
		IRETD

_asm_inthandler27:
		PUSH	ES
		PUSH	DS
		PUSHAD
		MOV		EAX,ESP
		PUSH	EAX
		MOV		AX,SS
		MOV		DS,AX
		MOV		ES,AX
		CALL	_inthandler27
		POP		EAX
		POPAD
		POP		DS
		POP		ES
		IRETD

_asm_inthandler2c:
		PUSH	ES
		PUSH	DS
		PUSHAD
		MOV		EAX,ESP
		PUSH	EAX
		MOV		AX,SS
		MOV		DS,AX
		MOV		ES,AX
		CALL	_inthandler2c
		POP		EAX
		POPAD
		POP		DS
		POP		ES
		IRETD

PUSHAD相当于保存当前CPU的寄存器EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI

这里就是把寄存器保存起来, 之后调整DS,ES,SS的数值相等, 设置段寄存器以及堆栈寄存器的数值相等, 这里是C语言的要求

  • 之后进行函数的注册
c
#define AR_INTGATE32	0x008e
	
	/* IDT的设置 */
	set_gatedesc(idt + 0x21, (int) asm_inthandler21, 2 * 8, AR_INTGATE32);
	set_gatedesc(idt + 0x27, (int) asm_inthandler27, 2 * 8, AR_INTGATE32);
	set_gatedesc(idt + 0x2c, (int) asm_inthandler2c, 2 * 8, AR_INTGATE32);

之后在发生中断之后会执行对应的函数

这里的2*8表示的是使用第二段, 乘以8是因为低三位有其他的表示内容

设置IDT的属性是0x8e表示为有效的属性

assembly
; 设置为CPU不接受中断, 之前在进入C环境的时候关闭了接受中断
_io_cli:	; void io_cli(void);
		CLI
		RET
; 设置为CPU接受中断, 在main函数中调用
_io_sti:	; void io_sti(void);
		STI
		RET

这里实际上设置的是IF标志位, 控制CPU的中断有效

c
void HariMain(void)
{
	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
	char s[40], mcursor[256];
	int mx, my;

	init_gdtidt();
	init_pic();
	io_sti(); /* 使能中断 */

	init_palette();
	init_screen8(binfo->vram, binfo->scrnx, binfo->scrny);
	mx = (binfo->scrnx - 16) / 2; /* 画面中央になるように座標計算 */
	my = (binfo->scrny - 28 - 16) / 2;
	init_mouse_cursor8(mcursor, COL8_008484);
	putblock8_8(binfo->vram, binfo->scrnx, 16, 16, mx, my, mcursor, 16);
	sprintf(s, "(%d, %d)", mx, my);
	putfonts8_asc(binfo->vram, binfo->scrnx, 0, 0, COL8_FFFFFF, s);

	io_out8(PIC0_IMR, 0xf9); /* 控制中断屏蔽位的数字 */
	io_out8(PIC1_IMR, 0xef); /* マウスを許可(11101111) */

	for (;;) {
		io_hlt();
	}
}