From c523af7b9f7594bb087781f852f466f9a2abc378 Mon Sep 17 00:00:00 2001
From: James Wang <jnwang@suse.com>
Date: Mon, 8 Jul 2019 22:16:21 +0800
Subject: [PATCH 1/5] Enable IRQ0

Inital PIT controller, enable IRQ0, serial console as output.
---
 hypervisor/int_entry.s | 20 +++++++++++++++++++-
 hypervisor/start.c     | 24 ++++++++++++++++++++++--
 include/common.h       |  8 +++++++-
 3 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/hypervisor/int_entry.s b/hypervisor/int_entry.s
index d1b71df..54d6658 100644
--- a/hypervisor/int_entry.s
+++ b/hypervisor/int_entry.s
@@ -1,10 +1,11 @@
 
 .text
 .code32
+.global inthandler20
 .global inthandler21
+.global inthandler24
 .global inthandler27
 .global inthandler2c
-.global inthandler24
 
 
 inthandler24:
@@ -23,6 +24,23 @@ inthandler24:
     pop     %es
     iretl
 
+#for timer
+inthandler20:
+    push    %es
+    push    %ds
+    pushal
+    movl    %esp,%eax
+    pushl    %eax
+    mov     %ss,%ax
+    mov     %ax,%ds
+    mov     %ax,%es
+    call    _inthandler20
+    popl     %eax
+    popal
+    pop     %ds
+    pop     %es
+    iretl
+
 #for keyboard
 inthandler21:
     push    %es
diff --git a/hypervisor/start.c b/hypervisor/start.c
index 01885fe..09bdbdc 100644
--- a/hypervisor/start.c
+++ b/hypervisor/start.c
@@ -82,9 +82,12 @@ static void init_gdtidt(void)
 	}
 	load_idtr(LIMIT_IDT, ADR_IDT);
 
-	set_gatedesc(idt + 0x24, (int)inthandler24, 2 * 8, AR_INTGATE32);
+	set_gatedesc(idt + 0x20, (int)inthandler20, 2 * 8, AR_INTGATE32);
 
 	set_gatedesc(idt + 0x21, (int)inthandler21, 2 * 8, AR_INTGATE32);
+
+	set_gatedesc(idt + 0x24, (int)inthandler24, 2 * 8, AR_INTGATE32);
+
 #if 1
 	/* IDT<82>Ì<90>Ý<92>è */
 	set_gatedesc(idt + 0x27, (int)inthandler27, 2 * 8, AR_INTGATE32);
@@ -251,6 +254,14 @@ static void init_palette(void)
 	/* static char <96>$<97>ß<82>Í<81>A<83>f<81>[<83>^<82>É<82>µ<82>©<8e>g<82>¦<82>È<82>¢<82>¯<82>ÇDB<96>$<97>ß<91><8a><93><96> */
 }
 
+static void init_pit(void)
+{
+    io_out8(PIT_CMD, 0x34);
+	io_out8(PIT_CH0, 0x9c);
+	io_out8(PIT_CH0, 0x2e);
+	return;
+}
+
 static void init_pic(void)
 {
     io_out8(PIC1_OCW1,  0xFF); 
@@ -404,12 +415,14 @@ void kernelstart(char *arg)
 
     init_gdtidt();
     init_pic();
+    init_pit();
     fifo_init(&key_fifo, 32, keybuffer);
     fifo_init(&mouse_fifo, 128, mousebuffer);
     fifo_init(&serial_fifo, 32, serialbuffer);
     io_sti();
 
-    io_out8(PIC0_DATA, 0xe9); /* PIC0<82>Æ<83>L<81>[<83>{<81>[<83>h<82>ð<8b><96><89>Â(11101001) */
+    io_out8(PIC0_DATA, 0xe8); /* PIC0<82>Æ<83>L<81>[<83>{<81>[<83>h<82>ð<8b><96><89>Â(11101001) */
+    //io_out8(PIC0_DATA, 0xe9); /* PIC0<82>Æ<83>L<81>[<83>{<81>[<83>h<82>ð<8b><96><89>Â(11101001) */
     io_out8(PIC1_DATA, 0xef); /* <83>}<83>E<83>X<82>ð<8b><96><89>Â(11101111) */
 
     init_keyboard();
@@ -525,6 +538,13 @@ void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, i
     return;
 }
 
+void _inthandler20(int *esp)
+{
+	unsigned char data;
+	io_out8(PIC0_COMMAND, PIC_EOI);
+    write_string_serial(".");
+	return;
+}
 void _inthandler21(int *esp)
 {
 	unsigned char data;
diff --git a/include/common.h b/include/common.h
index b9906c2..aad118d 100644
--- a/include/common.h
+++ b/include/common.h
@@ -84,6 +84,11 @@ void load_idtr(int limit, int addr);
 #define PIC1_DATA       (PIC1+1)
 #define PIC_EOI     0x20    /* End-of-interrupt command code */
 
+/* PIT chip I/O port*/
+#define PIT_CH0     0x40
+#define PIT_CMD     0x43
+
+
 /*GDT / IDT data*/
 
 #define ADR_IDT         0x0026f800
@@ -99,10 +104,11 @@ void load_idtr(int limit, int addr);
 /*Serial PORT*/
 #define PORT 0x3F8
 
+extern void inthandler20(void);
 extern void inthandler21(void);
+extern void inthandler24(void);
 extern void inthandler27(void);
 extern void inthandler2c(void);
-extern void inthandler24(void);
 
 struct mouse_info {
     char phase;

From 11e5e8d9a978d61780a86720745be6528a253691 Mon Sep 17 00:00:00 2001
From: James Wang <jnwang@suse.com>
Date: Mon, 8 Jul 2019 22:34:08 +0800
Subject: [PATCH 2/5] Move timer code out

timer.c is created for storing the code
---
 hypervisor/Makefile |  2 +-
 hypervisor/start.c  | 14 --------------
 hypervisor/timer.c  | 17 +++++++++++++++++
 include/serial.h    |  1 -
 include/timer.h     |  5 +++++
 5 files changed, 23 insertions(+), 16 deletions(-)
 create mode 100644 hypervisor/timer.c
 create mode 100644 include/timer.h

diff --git a/hypervisor/Makefile b/hypervisor/Makefile
index 1519bd0..a323122 100644
--- a/hypervisor/Makefile
+++ b/hypervisor/Makefile
@@ -3,7 +3,7 @@
 ASFLAGS = --32 -march=i486 -mtune=i486
 CFLAGS = -m32 -I../include
 
-COBJS = start.o font.o mouse.o int.o keyboard.o memtest.o mm.o fifo8.o serial.o console.o mmu.o libmmu.o
+COBJS = start.o font.o mouse.o int.o keyboard.o memtest.o mm.o fifo8.o serial.o console.o mmu.o libmmu.o timer.o
 SOBJS = int_entry.o libmemtest.o
 
 
diff --git a/hypervisor/start.c b/hypervisor/start.c
index 09bdbdc..fcff0a9 100644
--- a/hypervisor/start.c
+++ b/hypervisor/start.c
@@ -254,13 +254,6 @@ static void init_palette(void)
 	/* static char <96>$<97>ß<82>Í<81>A<83>f<81>[<83>^<82>É<82>µ<82>©<8e>g<82>¦<82>È<82>¢<82>¯<82>ÇDB<96>$<97>ß<91><8a><93><96> */
 }
 
-static void init_pit(void)
-{
-    io_out8(PIT_CMD, 0x34);
-	io_out8(PIT_CH0, 0x9c);
-	io_out8(PIT_CH0, 0x2e);
-	return;
-}
 
 static void init_pic(void)
 {
@@ -538,13 +531,6 @@ void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, i
     return;
 }
 
-void _inthandler20(int *esp)
-{
-	unsigned char data;
-	io_out8(PIC0_COMMAND, PIC_EOI);
-    write_string_serial(".");
-	return;
-}
 void _inthandler21(int *esp)
 {
 	unsigned char data;
diff --git a/hypervisor/timer.c b/hypervisor/timer.c
new file mode 100644
index 0000000..7698e3a
--- /dev/null
+++ b/hypervisor/timer.c
@@ -0,0 +1,17 @@
+#include "common.h"
+
+void init_pit(void)
+{
+    io_out8(PIT_CMD, 0x34);
+	io_out8(PIT_CH0, 0x9c);
+	io_out8(PIT_CH0, 0x2e);
+	return;
+}
+
+void _inthandler20(int *esp)
+{
+	unsigned char data;
+	io_out8(PIC0_COMMAND, PIC_EOI);
+    write_string_serial(".");
+	return;
+}
diff --git a/include/serial.h b/include/serial.h
index 316b0cf..41c50ca 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -1,6 +1,5 @@
 #ifndef _SERIAL_H
 #define _SERIAL_H
-#include "common.h"
 
 int serial_received();
 char read_serial();
diff --git a/include/timer.h b/include/timer.h
new file mode 100644
index 0000000..1f313bd
--- /dev/null
+++ b/include/timer.h
@@ -0,0 +1,5 @@
+#ifndef _TIMER_H
+#define _TIMER_H
+
+void init_pit(void);
+#endif

From cd2e9ff360de7ad44a29b3de799f431eaa215b3c Mon Sep 17 00:00:00 2001
From: James Wang <jnwang@suse.com>
Date: Mon, 10 Feb 2020 11:26:16 +0800
Subject: [PATCH 3/5] Add timer code

---
 hypervisor/timer.c | 54 ++++++++++++++++++++++++++++++++++++++++++++--
 include/timer.h    | 18 ++++++++++++++++
 2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/hypervisor/timer.c b/hypervisor/timer.c
index 7698e3a..ea0b80d 100644
--- a/hypervisor/timer.c
+++ b/hypervisor/timer.c
@@ -1,17 +1,67 @@
 #include "common.h"
+#include "timer.h"
+#include "serial.h"
+
+timer_zone timers;
+
 
 void init_pit(void)
 {
+    int i;
     io_out8(PIT_CMD, 0x34);
 	io_out8(PIT_CH0, 0x9c);
 	io_out8(PIT_CH0, 0x2e);
+
+    timers.count = 0;
+    for (i=0;i<MAX_TIMER;i++) {
+        timers.pool[i].flags = 0;
+    }
+    timer *t;
+    t = timer_alloc();
+    t->timeout = -1;
+    t->next = 0;
+    timers.current = t;
+    timers.next = -1;
+
 	return;
 }
+void timer_free(struct TIMER *timer)
+{
+	timer->flags = UNUSE; /* set to unused*/
+	return;
+}
+
+
+timer* timer_alloc(void)
+{
+    int i;
+    for (i = 0; i < MAX_TIMER; i++) {
+        if (timers.pool[i].flags == UNUSE) {
+            timers.pool[i].flags = USED;
+            return &timers.pool[i];
+        }
+    }
+    return 0; /* no free */
+}
 
 void _inthandler20(int *esp)
 {
-	unsigned char data;
+    timer *t;
 	io_out8(PIC0_COMMAND, PIC_EOI);
-    write_string_serial(".");
+    timers.count++;
+    if (timers.next > timers.count) {
+        return;
+    }
+    t = timers.current;
+    for(;;) {
+        if (t->timeout > timers.count) {
+            break;
+        }
+        t->flags = USED;
+        write_string_serial(".");
+        t = t->next;
+    }
+    timers.current = t;
+    timers.next = t->timeout;
 	return;
 }
diff --git a/include/timer.h b/include/timer.h
index 1f313bd..66d3b61 100644
--- a/include/timer.h
+++ b/include/timer.h
@@ -1,5 +1,23 @@
 #ifndef _TIMER_H
 #define _TIMER_H
+#include "common.h"
 
+#define MAX_TIMER   128
+
+#define UNUSE   0
+#define USED    1
+
+typedef struct TIMER {
+    struct TIMER *next;
+    unsigned int timeout, flags;
+    int data;
+}timer;
+
+typedef struct TIMER_POOL {
+    unsigned int count, next;
+    struct TIMER *current;
+    struct TIMER pool[MAX_TIMER];
+}timer_zone;
 void init_pit(void);
+timer* timer_alloc(void);
 #endif

From 08694c56845f328283e42b3487e782ed039e4c55 Mon Sep 17 00:00:00 2001
From: James Wang <jnwang@suse.com>
Date: Mon, 10 Feb 2020 21:50:32 +0800
Subject: [PATCH 4/5] retab all line use 4 spec instead of tab

---
 hypervisor/start.c | 280 ++++++++++++++++++++++-----------------------
 hypervisor/timer.c |  14 +--
 2 files changed, 146 insertions(+), 148 deletions(-)

diff --git a/hypervisor/start.c b/hypervisor/start.c
index fcff0a9..c58e8ed 100644
--- a/hypervisor/start.c
+++ b/hypervisor/start.c
@@ -16,8 +16,8 @@
 extern char mcursor[256];
 
 struct wjn {
-	int t;
-	int w;
+    int t;
+    int w;
 };
 
 struct fifo key_fifo;
@@ -61,40 +61,40 @@ static void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, i
 
 static void init_gdtidt(void)
 {
-	struct SEGMENT_DESCRIPTOR *gdt =
-	    (struct SEGMENT_DESCRIPTOR *)(ADR_GDT - (SYSSEG << 4));
-	struct GATE_DESCRIPTOR *idt =
-	    (struct GATE_DESCRIPTOR *)(ADR_IDT - (SYSSEG << 4));
-	//struct GATE_DESCRIPTOR    *idt = (struct GATE_DESCRIPTOR    *) ADR_IDT;
-	int i;
-	/* GDT<82>Ì<8f><89><8a>ú<89>» */
-	for (i = 0; i <= LIMIT_GDT / 8; i++) {
-		set_segmdesc(gdt + i, 0, 0, 0);
-	}
+    struct SEGMENT_DESCRIPTOR *gdt =
+        (struct SEGMENT_DESCRIPTOR *)(ADR_GDT - (SYSSEG << 4));
+    struct GATE_DESCRIPTOR *idt =
+        (struct GATE_DESCRIPTOR *)(ADR_IDT - (SYSSEG << 4));
+    //struct GATE_DESCRIPTOR    *idt = (struct GATE_DESCRIPTOR    *) ADR_IDT;
+    int i;
+    /* GDT<82>Ì<8f><89><8a>ú<89>» */
+    for (i = 0; i <= LIMIT_GDT / 8; i++) {
+        set_segmdesc(gdt + i, 0, 0, 0);
+    }
 #if 0
-	set_segmdesc(gdt + 2, 0xffffffff, 0x00010000, AR_CODE32_ER);
-	set_segmdesc(gdt + 3, LIMIT_BOTPAK, ADR_BOTPAK, AR_DATA32_RW);
-	load_gdtr(LIMIT_GDT, ADR_GDT);
+    set_segmdesc(gdt + 2, 0xffffffff, 0x00010000, AR_CODE32_ER);
+    set_segmdesc(gdt + 3, LIMIT_BOTPAK, ADR_BOTPAK, AR_DATA32_RW);
+    load_gdtr(LIMIT_GDT, ADR_GDT);
 #endif
-	/* IDT<82>Ì<8f><89><8a>ú<89>» */
-	for (i = 0; i <= LIMIT_IDT / 8; i++) {
-		set_gatedesc(idt + i, 0xfff, 0, 0);
-	}
-	load_idtr(LIMIT_IDT, ADR_IDT);
+    /* IDT<82>Ì<8f><89><8a>ú<89>» */
+    for (i = 0; i <= LIMIT_IDT / 8; i++) {
+        set_gatedesc(idt + i, 0xfff, 0, 0);
+    }
+    load_idtr(LIMIT_IDT, ADR_IDT);
 
-	set_gatedesc(idt + 0x20, (int)inthandler20, 2 * 8, AR_INTGATE32);
+    set_gatedesc(idt + 0x20, (int)inthandler20, 2 * 8, AR_INTGATE32);
 
-	set_gatedesc(idt + 0x21, (int)inthandler21, 2 * 8, AR_INTGATE32);
+    set_gatedesc(idt + 0x21, (int)inthandler21, 2 * 8, AR_INTGATE32);
 
-	set_gatedesc(idt + 0x24, (int)inthandler24, 2 * 8, AR_INTGATE32);
+    set_gatedesc(idt + 0x24, (int)inthandler24, 2 * 8, AR_INTGATE32);
 
 #if 1
-	/* IDT<82>Ì<90>Ý<92>è */
-	set_gatedesc(idt + 0x27, (int)inthandler27, 2 * 8, AR_INTGATE32);
+    /* IDT<82>Ì<90>Ý<92>è */
+    set_gatedesc(idt + 0x27, (int)inthandler27, 2 * 8, AR_INTGATE32);
 #endif
 
-	set_gatedesc(idt + 0x2c, (int)inthandler2c, 2 * 8, AR_INTGATE32);
-	return;
+    set_gatedesc(idt + 0x2c, (int)inthandler2c, 2 * 8, AR_INTGATE32);
+    return;
 }
 
 static void drawing_desktop()
@@ -112,7 +112,7 @@ static void drawing_desktop()
         0x00, 0x18, 0x18, 0x18, 0x18, 0x24, 0x24, 0x24,
         0x24, 0x7e, 0x42, 0x42, 0x42, 0xe7, 0x00, 0x00
     };
-        /*init mouse global data*/
+    /*init mouse global data*/
     mouse_status.mx = (xsize - 16) / 2;
     mouse_status.my = (ysize - 28 - 16) / 2;
     init_mouse_cursor8(mcursor, COL8_008484);
@@ -150,31 +150,31 @@ static void drawing_desktop()
 
 void drawing_mem_map()
 {
-	unsigned char *vram = VRAM_ADDR;
-	unsigned short xsize, ysize;
-	xsize = 320;
-	ysize = 200;
-	char buf[50];
-	//print memory map
-	struct MEMMAP *memmap = (struct MEMMAP *)(MEM_MAP_ADDR);
-	int pos = 20;
-	for (; memmap->type != 0;) {
-		sprintf(buf, "base:%X", memmap->base);
-		putfont8_string(vram, xsize, 8, pos, COL8_FFFFFF, font.Bitmap,
-				buf);
-		sprintf(buf, "len:%X", memmap->length);
-		putfont8_string(vram, xsize, 150, pos, COL8_FFFFFF, font.Bitmap,
-				buf);
-		if (memmap->type == 1) {
-			sprintf(buf, "%s", "free");
-		} else {
-			sprintf(buf, "%s", "reserve");
-		}
-		putfont8_string(vram, xsize, 270, pos, COL8_FFFFFF, font.Bitmap,
-				buf);
-		memmap++;
-		pos = pos + 16;
-	}
+    unsigned char *vram = VRAM_ADDR;
+    unsigned short xsize, ysize;
+    xsize = 320;
+    ysize = 200;
+    char buf[50];
+    //print memory map
+    struct MEMMAP *memmap = (struct MEMMAP *)(MEM_MAP_ADDR);
+    int pos = 20;
+    for (; memmap->type != 0;) {
+        sprintf(buf, "base:%X", memmap->base);
+        putfont8_string(vram, xsize, 8, pos, COL8_FFFFFF, font.Bitmap,
+                buf);
+        sprintf(buf, "len:%X", memmap->length);
+        putfont8_string(vram, xsize, 150, pos, COL8_FFFFFF, font.Bitmap,
+                buf);
+        if (memmap->type == 1) {
+            sprintf(buf, "%s", "free");
+        } else {
+            sprintf(buf, "%s", "reserve");
+        }
+        putfont8_string(vram, xsize, 270, pos, COL8_FFFFFF, font.Bitmap,
+                buf);
+        memmap++;
+        pos = pos + 16;
+    }
 }
 
 static void wait_KBC_sendready(void)
@@ -196,18 +196,18 @@ static void init_keyboard(void)
 static void enable_mouse(void)
 {
     /* 激活鼠标 */
-//    unsigned char status;
-//    wait_KBC_sendready();
-//    io_out8(PORT_KEYCMD, 0x20);
-//    wait_KBC_sendready();
-//    status = ((char)io_in8(PORT_KEYDAT)|0x2);
-//    status &= 0xDF;
-//    wait_KBC_sendready();
-//    io_out8(PORT_KEYCMD, 0x60);
-//    wait_KBC_sendready();
-//    io_out8(PORT_KEYDAT, status);
-//
-//
+    //    unsigned char status;
+    //    wait_KBC_sendready();
+    //    io_out8(PORT_KEYCMD, 0x20);
+    //    wait_KBC_sendready();
+    //    status = ((char)io_in8(PORT_KEYDAT)|0x2);
+    //    status &= 0xDF;
+    //    wait_KBC_sendready();
+    //    io_out8(PORT_KEYCMD, 0x60);
+    //    wait_KBC_sendready();
+    //    io_out8(PORT_KEYDAT, status);
+    //
+    //
     wait_KBC_sendready();
     io_out8(PORT_KEYCMD, KEYCMD_SENDTO_MOUSE);
     wait_KBC_sendready();
@@ -217,41 +217,41 @@ static void enable_mouse(void)
 
 static void set_palette(int start, int end, unsigned char *rgb)
 {
-	int i, eflags;
-	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;
-	}
-	return;
+    int i, eflags;
+    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;
+    }
+    return;
 }
 
 static void init_palette(void)
 {
-	static unsigned char table_rgb[16 * 3] = {
-		0x00, 0x00, 0x00,	/*  0: */
-		0xff, 0x00, 0x00,	/*  1: */
-		0x00, 0xff, 0x00,	/*  2: */
-		0xff, 0xff, 0x00,	/*  3: */
-		0x00, 0x00, 0xff,	/*  4: */
-		0xff, 0x00, 0xff,	/*  5: */
-		0x00, 0xff, 0xff,	/*  6: */
-		0xff, 0xff, 0xff,	/*  7: */
-		0xc6, 0xc6, 0xc6,	/*  8: */
-		0x84, 0x00, 0x00,	/*  9: */
-		0x00, 0x84, 0x00,	/* 10: */
-		0x84, 0x84, 0x00,	/* 11: */
-		0x00, 0x00, 0x84,	/* 12: */
-		0x84, 0x00, 0x84,	/* 13: */
-		0x00, 0x84, 0x84,	/* 14: */
-		0x84, 0x84, 0x84	/* 15: */
-	};
-	set_palette(0, 15, table_rgb);
-	return;
-
-	/* static char <96>$<97>ß<82>Í<81>A<83>f<81>[<83>^<82>É<82>µ<82>©<8e>g<82>¦<82>È<82>¢<82>¯<82>ÇDB<96>$<97>ß<91><8a><93><96> */
+    static unsigned char table_rgb[16 * 3] = {
+        0x00, 0x00, 0x00,   /*  0: */
+        0xff, 0x00, 0x00,   /*  1: */
+        0x00, 0xff, 0x00,   /*  2: */
+        0xff, 0xff, 0x00,   /*  3: */
+        0x00, 0x00, 0xff,   /*  4: */
+        0xff, 0x00, 0xff,   /*  5: */
+        0x00, 0xff, 0xff,   /*  6: */
+        0xff, 0xff, 0xff,   /*  7: */
+        0xc6, 0xc6, 0xc6,   /*  8: */
+        0x84, 0x00, 0x00,   /*  9: */
+        0x00, 0x84, 0x00,   /* 10: */
+        0x84, 0x84, 0x00,   /* 11: */
+        0x00, 0x00, 0x84,   /* 12: */
+        0x84, 0x00, 0x84,   /* 13: */
+        0x00, 0x84, 0x84,   /* 14: */
+        0x84, 0x84, 0x84    /* 15: */
+    };
+    set_palette(0, 15, table_rgb);
+    return;
+
+    /* static char <96>$<97>ß<82>Í<81>A<83>f<81>[<83>^<82>É<82>µ<82>©<8e>g<82>¦<82>È<82>¢<82>¯<82>ÇDB<96>$<97>ß<91><8a><93><96> */
 }
 
 
@@ -260,42 +260,42 @@ static void init_pic(void)
     io_out8(PIC1_OCW1,  0xFF); 
     io_out8(PIC0_OCW1,  0xFF); 
 
-	io_out8(PIC0_COMMAND, 0x11);
-	io_out8(PIC1_COMMAND, 0x11);
+    io_out8(PIC0_COMMAND, 0x11);
+    io_out8(PIC1_COMMAND, 0x11);
 
-	io_out8(PIC1_DATA, 0x28);
-	io_out8(PIC0_DATA, 0x20);
+    io_out8(PIC1_DATA, 0x28);
+    io_out8(PIC0_DATA, 0x20);
 
-	io_out8(PIC0_DATA, 1 << 2);
-	io_out8(PIC1_DATA, 2);
+    io_out8(PIC0_DATA, 1 << 2);
+    io_out8(PIC1_DATA, 2);
 
-	io_out8(PIC0_DATA, 0x01);	/*8086 mode for both */
-	io_out8(PIC1_DATA, 0x01);
+    io_out8(PIC0_DATA, 0x01);   /*8086 mode for both */
+    io_out8(PIC1_DATA, 0x01);
 
-	io_out8(PIC0_DATA, 0xfb);
-	io_out8(PIC1_DATA, 0xff);
+    io_out8(PIC0_DATA, 0xfb);
+    io_out8(PIC1_DATA, 0xff);
 
-	return;
+    return;
 }
 
 static void serial_handler(unsigned char data)
 {
-	serial_console();
+    serial_console();
 }
 
 #define PORT_KEYDAT 0x0060
 static void keyboard_handler(unsigned char data)
 {
-	unsigned char *vram = VRAM_ADDR;
-	unsigned short xsize, ysize;
-	unsigned char out_buffer[3];
-	unsigned char t;
-	xsize = 320;
-	ysize = 200;
-	if (data >= 0x81 || data == -1)
-		return;
-	out_buffer[0] = scancode[data];
-	if (out_buffer[0] == 0) {
+    unsigned char *vram = VRAM_ADDR;
+    unsigned short xsize, ysize;
+    unsigned char out_buffer[3];
+    unsigned char t;
+    xsize = 320;
+    ysize = 200;
+    if (data >= 0x81 || data == -1)
+        return;
+    out_buffer[0] = scancode[data];
+    if (out_buffer[0] == 0) {
         t=(data & 0xf0)>>4;
         if (t >= 0xa && t <= 0xf) {
             out_buffer[0] = 'A' + t - 10; 
@@ -327,16 +327,16 @@ static void keyboard_handler(unsigned char data)
         boxfill8(vram, xsize, COL8_FFFFFF, xsize -  3, ysize - 24, xsize -  3, ysize -  3);
 
         putfont8_string(vram,xsize, 283, 180, COL8_00FF00,font.Bitmap , out_buffer);
-		return;
-	}
-	out_buffer[1] = 0;
+        return;
+    }
+    out_buffer[1] = 0;
 
     putfont8_string(vram,xsize, 0, 0, COL8_FFFFFF,font.Bitmap , out_buffer);
 
-	if (data == 0x30 || data == 0xB0) {
-		putfont8_string(vram, xsize, 8, 100, COL8_FFFFFF, font.Bitmap,
-				(unsigned char *)"May the source be with you!");
-	}
+    if (data == 0x30 || data == 0xB0) {
+        putfont8_string(vram, xsize, 8, 100, COL8_FFFFFF, font.Bitmap,
+                (unsigned char *)"May the source be with you!");
+    }
 }
 
 static void mouse_handler(unsigned char data)
@@ -366,7 +366,7 @@ static void mouse_handler(unsigned char data)
         mouse_status.btn = mouse_status.buf[0] & 0x07;
         mouse_status.x = mouse_status.buf[1];
         mouse_status.y = mouse_status.buf[2];
-    
+
         if ((mouse_status.buf[0] & 0x10) != 0) {
             mouse_status.x |= 0xffffff00;
         }
@@ -375,7 +375,6 @@ static void mouse_handler(unsigned char data)
         }
         mouse_status.y = -mouse_status.y;
         boxfill8(VRAM_ADDR, xsize, COL8_008484, mouse_status.mx, mouse_status.my, mouse_status.mx + 15, mouse_status.my + 15);
-        //mouse_status.mx += mouse_status.x;
         mouse_status.mx += mouse_status.x;
         mouse_status.my += mouse_status.y;
         if (mouse_status.mx < 0) {
@@ -415,7 +414,6 @@ void kernelstart(char *arg)
     io_sti();
 
     io_out8(PIC0_DATA, 0xe8); /* PIC0<82>Æ<83>L<81>[<83>{<81>[<83>h<82>ð<8b><96><89>Â(11101001) */
-    //io_out8(PIC0_DATA, 0xe9); /* PIC0<82>Æ<83>L<81>[<83>{<81>[<83>h<82>ð<8b><96><89>Â(11101001) */
     io_out8(PIC1_DATA, 0xef); /* <83>}<83>E<83>X<82>ð<8b><96><89>Â(11101111) */
 
     init_keyboard();
@@ -445,7 +443,7 @@ void kernelstart(char *arg)
                 mouse_handler(data);
             } else if (fifo_status(&serial_fifo) > 0) {
                 io_sti();
-				serial_handler(0);
+                serial_handler(0);
             }
         }
     }
@@ -533,20 +531,20 @@ void boxfill8(unsigned char *vram, int xsize, unsigned char c, int x0, int y0, i
 
 void _inthandler21(int *esp)
 {
-	unsigned char data;
-	io_out8(PIC0_COMMAND, PIC_EOI);
-	data = io_in8(PORT_KEYDAT);
-	fifo_put(&key_fifo, data);
-	return;
+    unsigned char data;
+    io_out8(PIC0_COMMAND, PIC_EOI);
+    data = io_in8(PORT_KEYDAT);
+    fifo_put(&key_fifo, data);
+    return;
 }
 
 void _inthandler24(int *esp)
 {
-	unsigned char data;
-	io_out8(PIC0_COMMAND, 0x20);
-	data = read_serial();
-	fifo_put(&serial_fifo, data);
-	return;
+    unsigned char data;
+    io_out8(PIC0_COMMAND, 0x20);
+    data = read_serial();
+    fifo_put(&serial_fifo, data);
+    return;
 }
 
 
@@ -562,6 +560,6 @@ void _inthandler2c(int *esp)
 
 void _inthandler27(int *esp)
 {
-	io_out8(PIC0_COMMAND, 0x67);	/* IRQ-07<8e>ó<95>t<8a>®<97>¹<82>ðPIC<82>É<92>Ê<92>m(7-1<8e>Q<8f>Æ) */
-	return;
+    io_out8(PIC0_COMMAND, 0x67);    /* IRQ-07<8e>ó<95>t<8a>®<97>¹<82>ðPIC<82>É<92>Ê<92>m(7-1<8e>Q<8f>Æ) */
+    return;
 }
diff --git a/hypervisor/timer.c b/hypervisor/timer.c
index ea0b80d..c494dd9 100644
--- a/hypervisor/timer.c
+++ b/hypervisor/timer.c
@@ -9,8 +9,8 @@ void init_pit(void)
 {
     int i;
     io_out8(PIT_CMD, 0x34);
-	io_out8(PIT_CH0, 0x9c);
-	io_out8(PIT_CH0, 0x2e);
+    io_out8(PIT_CH0, 0x9c);
+    io_out8(PIT_CH0, 0x2e);
 
     timers.count = 0;
     for (i=0;i<MAX_TIMER;i++) {
@@ -23,12 +23,12 @@ void init_pit(void)
     timers.current = t;
     timers.next = -1;
 
-	return;
+    return;
 }
 void timer_free(struct TIMER *timer)
 {
-	timer->flags = UNUSE; /* set to unused*/
-	return;
+    timer->flags = UNUSE; /* set to unused*/
+    return;
 }
 
 
@@ -47,7 +47,7 @@ timer* timer_alloc(void)
 void _inthandler20(int *esp)
 {
     timer *t;
-	io_out8(PIC0_COMMAND, PIC_EOI);
+    io_out8(PIC0_COMMAND, PIC_EOI);
     timers.count++;
     if (timers.next > timers.count) {
         return;
@@ -63,5 +63,5 @@ void _inthandler20(int *esp)
     }
     timers.current = t;
     timers.next = t->timeout;
-	return;
+    return;
 }

From 389ccb7b33625b47dda55421180f70b669d725a3 Mon Sep 17 00:00:00 2001
From: James Wang <jnwang@suse.com>
Date: Wed, 12 Feb 2020 19:37:55 +0800
Subject: [PATCH 5/5] Add a chart for structure of timer

---
 doc/timer-design.odg | Bin 0 -> 13325 bytes
 hypervisor/timer.c   |  41 +++++++++++++++++++++++++++++++++--------
 include/timer.h      |  12 ++++++------
 3 files changed, 39 insertions(+), 14 deletions(-)
 create mode 100644 doc/timer-design.odg

diff --git a/doc/timer-design.odg b/doc/timer-design.odg
new file mode 100644
index 0000000000000000000000000000000000000000..0b475cf471fa6e318d78405f74071983941e2dd2
GIT binary patch
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literal 0
HcmV?d00001

diff --git a/hypervisor/timer.c b/hypervisor/timer.c
index c494dd9..eb6d94e 100644
--- a/hypervisor/timer.c
+++ b/hypervisor/timer.c
@@ -7,27 +7,53 @@ timer_zone timers;
 
 void init_pit(void)
 {
+    /*
+     * https://wiki.osdev.org/Programmable_Interval_Timer
+     */
+
     int i;
+    timer *t;
+    /* bit - 7
+     *
+     * 0 0 = Channel 0
+     *
+     * 1 1 = Access mode: lobyte/hibyte
+     *
+     * 0 1 0 = Mode 2 (rate generator)
+     * 
+     * 0 BCD/Binary mode: 0 = 16-bit binary, 1 = four-digit BCD
+     * 
+     * bit - 0
+     */
     io_out8(PIT_CMD, 0x34);
+    /*
+     * Write two times, data port is 8bits.
+     * so we have to write two times. This value helps PIT to generate 
+     * a frequency.
+     */
     io_out8(PIT_CH0, 0x9c);
     io_out8(PIT_CH0, 0x2e);
 
+
+    /* timer_zone datastructure init */
     timers.count = 0;
     for (i=0;i<MAX_TIMER;i++) {
-        timers.pool[i].flags = 0;
+        timers.pool[i].flags = UNUSE;
     }
-    timer *t;
+    /*pick up one of timers from pool*/
     t = timer_alloc();
     t->timeout = -1;
     t->next = 0;
+
+    /* set current timer to new timer*/
     timers.current = t;
     timers.next = -1;
 
     return;
 }
-void timer_free(struct TIMER *timer)
+void timer_free(timer *t)
 {
-    timer->flags = UNUSE; /* set to unused*/
+    t->flags = UNUSE; /* set to unused*/
     return;
 }
 
@@ -52,11 +78,10 @@ void _inthandler20(int *esp)
     if (timers.next > timers.count) {
         return;
     }
+
+    /*time is up, pick the current timer*/
     t = timers.current;
-    for(;;) {
-        if (t->timeout > timers.count) {
-            break;
-        }
+    while (t->timeout >= timers.count) {
         t->flags = USED;
         write_string_serial(".");
         t = t->next;
diff --git a/include/timer.h b/include/timer.h
index 66d3b61..71c6cbd 100644
--- a/include/timer.h
+++ b/include/timer.h
@@ -7,16 +7,16 @@
 #define UNUSE   0
 #define USED    1
 
-typedef struct TIMER {
-    struct TIMER *next;
+typedef struct timer{
+    struct timer *next;
     unsigned int timeout, flags;
     int data;
 }timer;
 
-typedef struct TIMER_POOL {
-    unsigned int count, next;
-    struct TIMER *current;
-    struct TIMER pool[MAX_TIMER];
+typedef struct timer_zone{
+    unsigned int count, next; /*next means timeout*/
+    timer *current;
+    timer pool[MAX_TIMER];
 }timer_zone;
 void init_pit(void);
 timer* timer_alloc(void);