使用定时器

12_day/Makefile

@@ -1,5 +1,5 @@
 OBJS_BOOTPACK = bootpack.obj naskfunc.obj hankaku.obj graphic.obj dsctbl.obj \
-		int.obj fifo.obj keyboard.obj mouse.obj memory.obj sheet.obj
+		int.obj fifo.obj keyboard.obj mouse.obj memory.obj sheet.obj timer.obj
 
 TOOLPATH = ../z_tools/
 INCPATH  = ../z_tools/haribote/

12_day/bootpack.c

@@ -3,6 +3,8 @@
 #include "bootpack.h"
 #include <stdio.h>
 
+void make_window8(unsigned char *buf, int xsize, int ysize, char *title);
+
 void HariMain(void)
 {
 	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
@@ -21,7 +23,8 @@ void HariMain(void)
 
 	fifo8_init(&keyfifo, 32, keybuf);
 	fifo8_init(&mousefifo, 128, mousebuf);
-	io_out8(PIC0_IMR, 0xf9); /* 开放PIC1和键盘中断(11111001) */
+	init_pit();
+	io_out8(PIC0_IMR, 0xf8); /* PIT和PIC1和键盘设置为许可(11111000) */
 	io_out8(PIC1_IMR, 0xef); /* 开放鼠标中断(11101111) */
 
 	init_keyboard();
@@ -169,4 +172,4 @@ void make_window8(unsigned char *buf, int xsize, int ysize, char *title)
 		}
 	}
 	return;
-}
+}

12_day/bootpack.h

@@ -22,6 +22,7 @@ void load_gdtr(int limit, int addr);
 void load_idtr(int limit, int addr);
 int load_cr0(void);
 void store_cr0(int cr0);
+void asm_inthandler20(void);
 void asm_inthandler21(void);
 void asm_inthandler27(void);
 void asm_inthandler2c(void);
@@ -166,3 +167,7 @@ void sheet_updown(struct SHEET *sht, int height);
 void sheet_refresh(struct SHEET *sht, int bx0, int by0, int bx1, int by1);
 void sheet_slide(struct SHEET *sht, int vx0, int vy0);
 void sheet_free(struct SHEET *sht);
+
+/* timer.c */
+void init_pit(void);
+void inthandler20(int *esp);

12_day/dsctbl.c

@@ -23,6 +23,7 @@ void init_gdtidt(void)
 	load_idtr(LIMIT_IDT, ADR_IDT);
 
 	/* IDT设置*/
+	set_gatedesc(idt + 0x20, (int) asm_inthandler20, 2 * 8, AR_INTGATE32);
 	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);

12_day/naskfunc.nas

@@ -12,9 +12,11 @@
 		GLOBAL	_io_load_eflags, _io_store_eflags
 		GLOBAL	_load_gdtr, _load_idtr
 		GLOBAL	_load_cr0, _store_cr0
-		GLOBAL	_asm_inthandler21, _asm_inthandler27, _asm_inthandler2c
+		GLOBAL	_asm_inthandler20, _asm_inthandler21
+		GLOBAL	_asm_inthandler27, _asm_inthandler2c
 		GLOBAL	_memtest_sub
-		EXTERN	_inthandler21, _inthandler27, _inthandler2c
+		EXTERN	_inthandler20, _inthandler21
+		EXTERN	_inthandler27, _inthandler2c
 
 [SECTION .text]
 
@@ -102,6 +104,22 @@ _store_cr0:		; void store_cr0(int cr0);
 		MOV		CR0,EAX
 		RET
 
+_asm_inthandler20:
+		PUSH	ES
+		PUSH	DS
+		PUSHAD
+		MOV		EAX,ESP
+		PUSH	EAX
+		MOV		AX,SS
+		MOV		DS,AX
+		MOV		ES,AX
+		CALL	_inthandler20
+		POP		EAX
+		POPAD
+		POP		DS
+		POP		ES
+		IRETD
+
 _asm_inthandler21:
 		PUSH	ES
 		PUSH	DS

12_day/timer.c

@@ -0,0 +1,20 @@
+/* 定时器 */
+
+#include "bootpack.h"
+
+#define PIT_CTRL 0x0043
+#define PIT_CNT0 0x0040
+
+void init_pit(void)
+{
+	io_out8(PIT_CTRL, 0x43);
+	io_out8(PIT_CNT0, 0x9c);
+	io_out8(PIT_CNT0, 0x2e);
+}
+
+void inthandler20(int *esp)
+{
+	io_out8(PIC0_OCW2, 0x60); /* 把IRQ-00信号接收完了的信息通知给PIC */
+	/* 暂时什么也不做 */    
+	return;
+}