挑战任务切换

15_day/bootpack.c

@@ -7,6 +7,15 @@ void make_window8(unsigned char *buf, int xsize, int ysize, char *title);
 void putfonts8_asc_sht(struct SHEET *sht, int x, int y, int c, int b, char *s, int l);
 void make_textbox8(struct SHEET *sht, int x0, int y0, int sx, int sy, int c);
 
+struct TSS32 {
+	int backlink, esp0, ss0, esp1, ss1, esp2, ss2, cr3;
+	int eip, eflags, eax, ecx, edx, ebx, esp, ebp, esi, edi;
+	int es, cs, ss, ds, fs, gs;
+	int ldtr, iomap;
+};
+
+void task_b_main(void);
+
 void HariMain(void)
 {
 	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
@@ -14,7 +23,7 @@ void HariMain(void)
 	char s[40];
 	int fifobuf[128];
 	struct TIMER *timer, *timer2, *timer3;
-	int mx, my, i, cursor_x, cursor_c;
+	int mx, my, i, cursor_x, cursor_c, task_b_esp;
 	unsigned int memtotal;
 	struct MOUSE_DEC mdec;
 	struct MEMMAN *memman = (struct MEMMAN *) MEMMAN_ADDR;
@@ -29,6 +38,8 @@ void HariMain(void)
 		0, 0, 0, 0, 0, 0, 0, '7', '8', '9', '-', '4', '5', '6', '+', '1',
 		'2', '3', '0', '.'
 	};
+	struct TSS32 tss_a, tss_b;
+	struct SEGMENT_DESCRIPTOR *gdt = (struct SEGMENT_DESCRIPTOR *) ADR_GDT;
 
 	init_gdtidt();
 	init_pic();
@@ -85,6 +96,31 @@ void HariMain(void)
 			memtotal / (1024 * 1024), memman_total(memman) / 1024);
 	putfonts8_asc_sht(sht_back, 0, 32, COL8_FFFFFF, COL8_008484, s, 40);
 
+	tss_a.ldtr = 0;
+	tss_a.iomap = 0x40000000;
+	tss_b.ldtr = 0;
+	tss_b.iomap = 0x40000000;
+	set_segmdesc(gdt + 3, 103, (int) &tss_a, AR_TSS32);
+	set_segmdesc(gdt + 4, 103, (int) &tss_b, AR_TSS32);
+	load_tr(3 * 8);
+	task_b_esp = memman_alloc_4k(memman, 64 * 1024) + 64 * 1024;
+	tss_b.eip = (int) &task_b_main;
+	tss_b.eflags = 0x00000202; /* IF = 1; */
+	tss_b.eax = 0;
+	tss_b.ecx = 0;
+	tss_b.edx = 0;
+	tss_b.ebx = 0;
+	tss_b.esp = task_b_esp;
+	tss_b.ebp = 0;
+	tss_b.esi = 0;
+	tss_b.edi = 0;
+	tss_b.es = 1 * 8;
+	tss_b.cs = 2 * 8;
+	tss_b.ss = 1 * 8;
+	tss_b.ds = 1 * 8;
+	tss_b.fs = 1 * 8;
+	tss_b.gs = 1 * 8;
+
 	for (;;) {
 		io_cli();
 		if (fifo32_status(&fifo) == 0) {
@@ -149,6 +185,7 @@ void HariMain(void)
 				}
 			} else if (i == 10) { /* 10秒定时器 */
 				putfonts8_asc_sht(sht_back, 0, 64, COL8_FFFFFF, COL8_008484, "10[sec]", 7);
+				taskswitch4();
 			} else if (i == 3) { /* 3秒定时器 */
 				putfonts8_asc_sht(sht_back, 0, 80, COL8_FFFFFF, COL8_008484, "3[sec]", 6);
 			} else if (i <= 1) { /* 光标用定时器*/
@@ -238,3 +275,8 @@ void make_textbox8(struct SHEET *sht, int x0, int y0, int sx, int sy, int c)
 	boxfill8(sht->buf, sht->bxsize, c, x0 - 1, y0 - 1, x1 + 0, y1 + 0);
 	return;
 }
+
+void task_b_main(void)
+{
+	for (;;) { io_hlt(); }
+}

15_day/bootpack.h

@@ -22,11 +22,13 @@ void load_gdtr(int limit, int addr);
 void load_idtr(int limit, int addr);
 int load_cr0(void);
 void store_cr0(int cr0);
+void load_tr(int tr);
 void asm_inthandler20(void);
 void asm_inthandler21(void);
 void asm_inthandler27(void);
 void asm_inthandler2c(void);
 unsigned int memtest_sub(unsigned int start, unsigned int end);
+void taskswitch4(void);
 
 /* fifo.c */
 struct FIFO32 {
@@ -87,6 +89,7 @@ void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar);
 #define LIMIT_BOTPAK	0x0007ffff
 #define AR_DATA32_RW	0x4092
 #define AR_CODE32_ER	0x409a
+#define AR_TSS32		0x0089
 #define AR_INTGATE32	0x008e
 
 /* int.c */
@@ -124,7 +127,6 @@ int mouse_decode(struct MOUSE_DEC *mdec, unsigned char dat);
 /* memory.c */
 #define MEMMAN_FREES 4090 /* 大约是32KB*/
 #define MEMMAN_ADDR			0x003c0000
-
 struct FREEINFO { /* 可用信息 */
 	unsigned int addr, size;
 };
@@ -132,7 +134,6 @@ struct MEMMAN { /* 内存管理 */
 	int frees, maxfrees, lostsize, losts;
 	struct FREEINFO free[MEMMAN_FREES];
 };
-
 unsigned int memtest(unsigned int start, unsigned int end);
 void memman_init(struct MEMMAN *man);
 unsigned int memman_total(struct MEMMAN *man);
@@ -143,21 +144,17 @@ int memman_free_4k(struct MEMMAN *man, unsigned int addr, unsigned int size);
 
 /* sheet.c */
 #define MAX_SHEETS		256
-#define SHEET_USE  1
-
 struct SHEET {
 	unsigned char *buf;
 	int bxsize, bysize, vx0, vy0, col_inv, height, flags;
 	struct SHTCTL *ctl;
 };
-
 struct SHTCTL {
 	unsigned char *vram, *map;
 	int xsize, ysize, top;
 	struct SHEET *sheets[MAX_SHEETS];
 	struct SHEET sheets0[MAX_SHEETS];
 };
-
 struct SHTCTL *shtctl_init(struct MEMMAN *memman, unsigned char *vram, int xsize, int ysize);
 struct SHEET *sheet_alloc(struct SHTCTL *ctl);
 void sheet_setbuf(struct SHEET *sht, unsigned char *buf, int xsize, int ysize, int col_inv);
@@ -167,7 +164,7 @@ void sheet_slide(struct SHEET *sht, int vx0, int vy0);
 void sheet_free(struct SHEET *sht);
 
 /* timer.c */
-#define MAX_TIMER 500
+#define MAX_TIMER		500
 struct TIMER {
 	struct TIMER *next;
 	unsigned int timeout, flags;
@@ -180,11 +177,9 @@ struct TIMERCTL {
 	struct TIMER timers0[MAX_TIMER];
 };
 extern struct TIMERCTL timerctl;
-
 void init_pit(void);
 struct TIMER *timer_alloc(void);
 void timer_free(struct TIMER *timer);
 void timer_init(struct TIMER *timer, struct FIFO32 *fifo, int data);
 void timer_settime(struct TIMER *timer, unsigned int timeout);
 void inthandler20(int *esp);
-

15_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	_load_tr
 		GLOBAL	_asm_inthandler20, _asm_inthandler21
 		GLOBAL	_asm_inthandler27, _asm_inthandler2c
 		GLOBAL	_memtest_sub
+		GLOBAL	_taskswitch4
 		EXTERN	_inthandler20, _inthandler21
 		EXTERN	_inthandler27, _inthandler2c
 
@@ -104,6 +106,10 @@ _store_cr0:		; void store_cr0(int cr0);
 		MOV		CR0,EAX
 		RET
 
+_load_tr:		; void load_tr(int tr);
+		LTR		[ESP+4]			; tr
+		RET
+
 _asm_inthandler20:
 		PUSH	ES
 		PUSH	DS
@@ -200,3 +206,7 @@ mts_fin:
 		POP		ESI
 		POP		EDI
 		RET
+
+_taskswitch4:	; void taskswitch4(void);
+		JMP		4*8:0
+		RET