From b070592c0b5a909665c7609088581417b34a6d6f Mon Sep 17 00:00:00 2001
From: catfood <protonghost@outlook.com>
Date: Mon, 9 Jan 2023 20:00:10 +0800
Subject: [PATCH] a proto type

---
 include/console.h   |  11 +-
 include/memman.h    |   2 +-
 include/x86.h       |   2 +-
 include/yieldlock.h |  13 +++
 kernel/Makefrag     |   1 +
 kernel/fbcon.c      | 272 ++++++++++++++++++++++++++++++++------------
 kernel/keyboard.c   |  25 +++-
 kernel/ktest.c      |   2 +-
 kernel/main.c       |  18 +--
 kernel/pagetbl.c    |   2 +-
 kernel/proc.c       |  63 +++++-----
 kernel/protect.c    |  34 +++---
 kernel/tty.c        |  19 +++-
 lib/kprintf.c       |   4 +-
 user/shell_0.c      |   6 +-
 user/test.c         |   9 +-
 16 files changed, 335 insertions(+), 148 deletions(-)
 create mode 100644 include/yieldlock.h

diff --git a/include/console.h b/include/console.h
index 2a390e7..c149b7c 100644
--- a/include/console.h
+++ b/include/console.h
@@ -13,7 +13,7 @@
 
 #ifndef _ORANGES_CONSOLE_H_
 #define _ORANGES_CONSOLE_H_
-
+#include "tty.h"
 /* CONSOLE */
 typedef struct s_console
 {
@@ -28,10 +28,19 @@ typedef struct fb_console {
 
 } fb_console;
 
+typedef struct ringbuf {
+	unsigned int head;
+	unsigned int tail;
+	unsigned int maxsize;
+	unsigned int size;
+	void* buf;
+} ringbuf_t;
+
 void simpleconsole_init();
 void simpleconsole_write(char* buf, int nr);
 void simpleconsole_transfer(void (*write)(char ch));
 void simpleconsole_setcur(int row, int col);
+void fbcon_tty_write(NTTY* tty, char ch) ;
 
 #define CON_MAX_LOGBUF 1024
 
diff --git a/include/memman.h b/include/memman.h
index c83c855..46deed1 100644
--- a/include/memman.h
+++ b/include/memman.h
@@ -4,7 +4,7 @@
 #define MEMMAN_FREES	4090		//32KB
 #define MEMMAN_ADDR	0x01ff0000	//存memman，31M960K
 #define FMIBuff		0x007ff000	//loader中getFreeMemInfo返回值存放起始地址(7M1020K)
-#define KWALL		0x00600000
+#define KWALL		0x00500000
 #define WALL		0x00A00000
 #define UWALL		0x01000000
 #define MEMSTART	0x00400000
diff --git a/include/x86.h b/include/x86.h
index c9316d2..0f3a10b 100644
--- a/include/x86.h
+++ b/include/x86.h
@@ -209,7 +209,7 @@ xchg(volatile u32 *addr, u32 newval)
 	u32 result;
 
 	// The + in "+m" denotes a read-modify-write operand.
-	asm volatile("lock\n\t xchgl %0, %1"
+	asm volatile("lock; xchgl %0, %1"
 		     : "+m" (*addr), "=a" (result)
 		     : "1" (newval)
 		     : "cc");
diff --git a/include/yieldlock.h b/include/yieldlock.h
new file mode 100644
index 0000000..95327d9
--- /dev/null
+++ b/include/yieldlock.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "x86.h"
+#include "proto.h"
+static inline void acquire_y(volatile u32* lock) {
+	while (xchg(lock, 1) == 1){
+		sys_yield();
+	}
+}
+
+static inline void release_y(volatile u32* lock) {
+    xchg(lock, 0);
+}
\ No newline at end of file
diff --git a/kernel/Makefrag b/kernel/Makefrag
index 3337257..da4b536 100644
--- a/kernel/Makefrag
+++ b/kernel/Makefrag
@@ -34,6 +34,7 @@ KERN_SRCFILES :=kernel/kernel.asm	\
 		kernel/vga.c \
 		kernel/pci.c \
 		kernel/bga.c \
+		kernel/fbcon.c \
 		lib/klib.c		\
 
 
diff --git a/kernel/fbcon.c b/kernel/fbcon.c
index cfa6d08..b9796d1 100644
--- a/kernel/fbcon.c
+++ b/kernel/fbcon.c
@@ -1,101 +1,229 @@
-#include "type.h"
-#include "const.h"
-#include "protect.h"
-#include "string.h"
-#include "proc.h"
-#include "tty.h"
-#include "console.h"
-#include "global.h"
-#include "proto.h"
-#include "keyboard.h"
-#include "x86.h"
-#include "memman.h"
-#include "stdio.h"
-#include "serialport.h"
 #include "bga.h"
+#include "console.h"
+#include "const.h"
+#include "global.h"
+#include "keyboard.h"
+#include "memman.h"
+#include "proc.h"
+#include "protect.h"
+#include "proto.h"
+#include "serialport.h"
+#include "spinlock.h"
+#include "stdio.h"
+#include "string.h"
+#include "tty.h"
+#include "type.h"
+#include "x86.h"
+#include "yieldlock.h"
 
-
-static int _cursor_x = 0;
-static int _cursor_y = 0;
+static int cur_col = 0;
+static int cur_row = 0;
+static int _fnt_char_width = 0;
+static int _fnt_char_height = 0;
+static int _scr_max_rows = 0;
+static int _scr_max_cols = 0;
+static int _fbbufsize = 0;
 static int _fbwidth = 0;
 static int _fbheight = 0;
 static int _fbpixels_per_row = 0;
 static int _fbscale = 1;
+static int cursor_blink = 0;
 static uint32_t _basecolor = 0x0;
 static uintptr_t _fb_paddr = 0;
-volatile uint32_t* _fb = NULL;
+static uint32_t* _fb = NULL;
+static uint32_t* cur_fb = NULL;
+static volatile int framecnt = 0;
+static char* textbuf;
+#define UNIT_CHAR_H (_fnt_char_height * _fbscale)
+#define UNIT_CHAR_W (_fnt_char_width * _fbscale)
+
 #include "font8x8.h"
-static void update_cursor_position(char c)
-{
-    _cursor_x += 8 * _fbscale;
+static void fast_copy(void* dst, void* src, int len);
 
-    if (c == '\n' || (_cursor_x + 8 * _fbscale) > _fbwidth) {
-        _cursor_y += 8 * _fbscale;
-        _cursor_x = 0;
-
-        if ((_cursor_y + 8 * _fbscale + 2) > _fbheight) {
-            _cursor_y = 0;
+static void fbcon_draw_raw(int row, int col, char ch) {
+    for (int x = 0; x < UNIT_CHAR_H; x++) {
+        for (int y = 0; y < UNIT_CHAR_W; y++) {
+            uint32_t ind = (col * UNIT_CHAR_W + x) + ((row * UNIT_CHAR_H + y) * _fbpixels_per_row);
+            uint32_t clr = _basecolor;
+            if (font8x8_basic[ch & 0x7f][y / _fbscale] &
+                (1 << (x / _fbscale))) {
+                clr ^= 0xffffffff;
+            }
+            cur_fb[ind] = clr;
         }
     }
 }
+
 static void draw_cursor() {
-	for (int x = 0; x < (8 * _fbscale); x++) {
-        for (int y = 0; y < (8 * _fbscale); y++) {
-            uint32_t ind = (_cursor_x + x) + ((_cursor_y + y) * _fbpixels_per_row);
-            uint32_t clr = _basecolor;
-            if (font8x8_basic[0][y / _fbscale] & (1 << (x / _fbscale))) {
-                clr ^= 0xffffffff;
-            }
-            _fb[ind] = clr;
-        }
-    }
+    fbcon_draw_raw(cur_row, cur_col, 0);
 }
-static void draw_char_on_screen(char c)
-{
-    for (int x = 0; x < (8 * _fbscale); x++) {
-        for (int y = 0; y < (8 * _fbscale); y++) {
-            uint32_t ind = (_cursor_x + x) + ((_cursor_y + y) * _fbpixels_per_row);
-            uint32_t clr = _basecolor;
-            if (font8x8_basic[c & 0x7f][y / _fbscale] & (1 << (x / _fbscale))) {
-                clr ^= 0xffffffff;
-            }
-            _fb[ind] = clr;
-        }
-    }
-    update_cursor_position(c);
+
+static void draw_cursor_clear() {
+    fbcon_draw_raw(cur_row, cur_col, 1);
 }
-int screen_setup()
-{
-    _cursor_x = 0;
-    _cursor_y = 0;
+
+static void fbcon_scroll() {
+    int lineoffset = _fbwidth * _fnt_char_height * _fbscale;
+    fast_copy(  (void*)cur_fb, 
+                (void*)cur_fb + lineoffset, 
+                _fbbufsize - lineoffset);
+    memset((void*)cur_fb + _fbbufsize - lineoffset, 0, lineoffset);
+}
+
+static void fbcon_putchar(char ch) {
+    switch (ch)
+	{
+	case '\n':
+		cur_row ++;
+		cur_col = 0;
+		if (cur_row >= _scr_max_rows) {
+			fbcon_scroll();
+			cur_row --;
+		}
+		break;
+	case '\r':
+		cur_col = 0;
+		break;
+	case '\b':
+		if (cur_col == 0) {
+			if (cur_row) cur_row --;
+			cur_col = _scr_max_cols - 1;
+		}
+		else {
+			cur_col --;
+		}
+		break;
+	default:
+		fbcon_draw_raw(cur_row, cur_col, ch);
+		cur_col ++;
+		if (cur_col >= _scr_max_cols) {
+			cur_col = 0;
+			cur_row ++;
+		}
+
+		if (cur_row >= _scr_max_rows) {
+			fbcon_scroll();
+			cur_row --;
+		}
+		break;
+	}
+}
+
+volatile u32 buflock;
+static char _buf1[TTY_IN_BYTES];
+ringbuf_t writebuf;
+
+int screen_setup() {
+    cur_col = 0;
+    cur_row = 0;
+    _fnt_char_width = 8;
+    _fnt_char_height = 8;
     _fb = (uint32_t*)bga_ioctl(BGA_GET_BUFFER, 0);
     _fb_paddr = bga_ioctl(BGA_GET_BUFFER, 0);
     _fbwidth = bga_ioctl(BGA_GET_WIDTH, 0);
     _fbheight = bga_ioctl(BGA_GET_HEIGHT, 0);
     _fbpixels_per_row = _fbwidth;
+    _fbbufsize = _fbwidth * _fbheight * 4;
+    kprintf("bufsz = %p\n", _fbbufsize);
     _fbscale = 2;
+    cur_fb = _fb;
+    _scr_max_cols = _fbwidth / _fnt_char_width / _fbscale;
+    _scr_max_rows = _fbheight / _fnt_char_height / _fbscale;
 
+    _basecolor = 0;
+    cursor_blink = 1;
+    writebuf.buf = &_buf1;
+    writebuf.head = writebuf.tail = writebuf.size = 0;
+    writebuf.maxsize = TTY_IN_BYTES;
+    framecnt = 0;
+    
     return 0;
 }
 
-void task_tty()
-{
-	// main rountine for drawing framebuffered console
+static inline void bufpush(ringbuf_t* buf, char data) {
+    ((char*)buf->buf)[buf->tail] = data;
+    buf->tail = NEXT(buf->tail, buf->maxsize);
+    if (buf->head == buf->tail)
+        buf->head = NEXT(buf->head, buf->maxsize);
+    else
+        buf->size++;
+}
 
-	char text1[] = "hello world\n shit\b idiot\n retard fuckyou\n";
-	char text2[] = "shabi ni\n ni zhe ge zhi zhangg\b ma de la ji wan yi er\n";
-	
-	screen_setup();
+static inline char bufpop(ringbuf_t* buf) {
+    if (buf->size == 0) return -1;
+    char retval = ((char*)buf->buf)[buf->head];
+    buf->head = NEXT(buf->head, buf->maxsize);
+    buf->size--;
+    return retval;
+}
+
+static void do_fbcon_write(char* buf, int nr) {
+    while (xchg(&buflock, 1) == 1)
+        sys_yield();
+    while (nr--) {
+        bufpush(&writebuf, *buf++);
+    }
+    xchg(&buflock, 0);
+}
+
+void fbcon_tty_write(NTTY* tty, char ch) {
+    do_fbcon_write(&ch, 1);
+}
+
+static void blink_ctrl() {
+    if (framecnt < 10) {
+        framecnt ++;
+        // kprintf("frame %d\n", framecnt);
+    }
+    else {
+        framecnt = 0;
+        cursor_blink = ! cursor_blink;
+        // kprintf("should change\n");
+    }
+}
+
+static void fast_copy(void* dst, void* src, int len) {
+    // assume all address align, 32 bytes a time
+    uint32_t* _src = src;
+    uint32_t* _dst = dst;
+    int i;
+    for (i = 0; i < len / 4; i += 8) {
+        _dst[i + 0] = _src[i + 0];
+        _dst[i + 1] = _src[i + 1];
+        _dst[i + 2] = _src[i + 2];
+        _dst[i + 3] = _src[i + 3];
+        _dst[i + 4] = _src[i + 4];
+        _dst[i + 5] = _src[i + 5];
+        _dst[i + 6] = _src[i + 6];
+        _dst[i + 7] = _src[i + 7];
+    }
+}
+
+void task_tty() {
+    // main rountine for drawing framebuffered console
+    screen_setup();
     mmap((u32)_fb, _fb_paddr, _fbwidth * _fbheight * 4 * 2);
-	for (char* p = text1; *p; ++ p){
-			draw_char_on_screen(*p);
-		}
-		for (char* p = text2; *p; ++ p){
-			draw_char_on_screen(*p);
-		}
-		draw_cursor();
-	while (1)
-	{
-		
-	}
+    buflock = 0;
+    // fbcon_write(text1, strlen(text1));
+    int cur_buf = 0, last_buf = 1;
+    while (1) {
+        fast_copy((void*)_fb + cur_buf * _fbbufsize, (void*)_fb + last_buf * _fbbufsize, _fbbufsize);
+        draw_cursor_clear();
+        while (xchg(&buflock, 1) == 1)
+            yield();
+        while (writebuf.size) {
+            char ch = bufpop(&writebuf);
+            fbcon_putchar(ch);
+        }
+        xchg(&buflock, 0);
+        blink_ctrl();
+        if (cursor_blink)
+            draw_cursor();
+        bga_ioctl(BGA_SWAP_BUFFERS, cur_buf);
+        last_buf = cur_buf;
+        cur_buf = !cur_buf;
+        cur_fb = (void*)_fb + cur_buf * _fbbufsize;
+
+        sleep(5); // to no need to refresh that fast
+    }
 }
\ No newline at end of file
diff --git a/kernel/keyboard.c b/kernel/keyboard.c
index 42a38ec..f85bf49 100644
--- a/kernel/keyboard.c
+++ b/kernel/keyboard.c
@@ -15,6 +15,7 @@
 #include "minix_keymap.h"
 #include "serialport.h"
 #include "memman.h"
+#include "yieldlock.h"
 
 static int code_with_E0;
 static int shift_l;		/* l shift state	*/
@@ -370,6 +371,7 @@ static void kbd_process(unsigned char scode)
 	kbd_state = 0;
 }
 
+static u32 kbdlock;
 
 #define LASTKEY(x) LAST(x, TTY_IN_BYTES)
 #define NEXTKEY(x) NEXT(x, TTY_IN_BYTES)
@@ -386,6 +388,7 @@ void ps2_tty_init(NTTY *tty)
 	// kprintf("kbd buf: %p\n", kbd->buf);
 	kbd->head = kbd->tail = kbd->readable = 0;
 	kbd->len = 0;
+	kbdlock = 0;
 }
 
 int ps2_tty_read(NTTY *tty, char *buf, int nr)
@@ -395,11 +398,15 @@ int ps2_tty_read(NTTY *tty, char *buf, int nr)
 	int i = 0;
 	while (1)
 	{
+		while (xchg(&kbdlock, 1) == 1)
+			sys_yield();
+
 		if (kbd->readable)
 		{
-			disable_int();
 			break;
 		}
+		release_y(&kbdlock);
+		sys_yield();
 	}
 	assert(kbd->buf);
 	u8 *ibuf = kbd->buf;
@@ -411,7 +418,7 @@ int ps2_tty_read(NTTY *tty, char *buf, int nr)
 	}
 	kbd->readable -= i;
 	kbd->len -= i;
-	enable_int();
+	release_y(&kbdlock);
 	return i;
 }
 
@@ -427,7 +434,7 @@ void ps2_tty_flush(NTTY *tty)
 void ps2_tty_recvbuf(NTTY *tty, u32 key)
 {
 	// kprintf("%x\n", key);
-	disable_int();
+	// disable_int();
 	assert(tty->input_buf);
 	keyboard_buf *kbd = (keyboard_buf *)tty->input_buf;
 	u8* buf = kbd->buf;
@@ -481,14 +488,19 @@ void ps2_tty_recvbuf(NTTY *tty, u32 key)
 		{
 		case '\r':
 		case '\n': // escape ENTER
+			while (xchg(&kbdlock, 1) == 1)
+				sys_yield();
 			tty->write(tty, '\n');
 			buf[kbd->tail] = '\n';
 			kbd->len++;
 			kbd->tail = NEXTKEY(kbd->tail);
 			kbd->readable = CYCLE_SUB(kbd->head, kbd->tail, TTY_IN_BYTES);
+			release_y(&kbdlock);
 			// kprintf("len=%d, h=%d, t=%d, rd=%d\n", kbd->len, kbd->head, kbd->tail, kbd->readable);
 			break;
 		case '\b':
+			while (xchg(&kbdlock, 1) == 1)
+				sys_yield();
 			if (kbd->len > kbd->readable)
 			{
 				// vga_tty_backspace(tty);
@@ -498,22 +510,25 @@ void ps2_tty_recvbuf(NTTY *tty, u32 key)
 				kbd->len--;
 				kbd->tail = LASTKEY(kbd->tail);
 			}
+			release_y(&kbdlock);
 			break;
 
 		default:
+			while (xchg(&kbdlock, 1) == 1);
 			if ((key & 0xff) == 0)
 				return;
 			if (kbd->len == TTY_IN_BYTES - 1)
 				return; // leave one space for ctrl ascii
-			tty->write(tty, key);
 			buf[kbd->tail] = (u8)(key & 0xff);
 			// kprintf("%d %d %d", key & 0xff, kbd->tail, buf[kbd->tail]);
 			kbd->len++;
 			kbd->tail = NEXTKEY(kbd->tail);
+			release_y(&kbdlock);
+			tty->write(tty, key);
 			// kprintf("len=%d, h=%d, t=%d, rd=%d\n", kbd->len, kbd->head, kbd->tail, kbd->readable);
 			break;
 		}
 		tty->ioctl(tty, IOCTL_CMD_TTY_FLUSH, 0);
 	}
-	enable_int();
+	// enable_int();
 }
diff --git a/kernel/ktest.c b/kernel/ktest.c
index 43c4391..2b5223b 100644
--- a/kernel/ktest.c
+++ b/kernel/ktest.c
@@ -132,7 +132,7 @@ void initial()
 	do_vclose(stdout);
 	do_vclose(stderr);
 
-	exec("orange/shell_1.bin");
+	exec("orange/shell_0.bin");
 
 	while (1)
 		;
diff --git a/kernel/main.c b/kernel/main.c
index 706ea19..eec1280 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -174,18 +174,18 @@ static int initialize_processes()
 		/**************LDT*********************************/
 		p_proc->task.ldt_sel = selector_ldt;
 		memcpy(&p_proc->task.ldts[0], &gdt[SELECTOR_KERNEL_CS >> 3], sizeof(DESCRIPTOR));
-		p_proc->task.ldts[0].attr1 = DA_C | PRIVILEGE_TASK << 5;
+		p_proc->task.ldts[0].attr1 = DA_C | PRIVILEGE_KRNL << 5;
 		memcpy(&p_proc->task.ldts[1], &gdt[SELECTOR_KERNEL_DS >> 3], sizeof(DESCRIPTOR));
-		p_proc->task.ldts[1].attr1 = DA_DRW | PRIVILEGE_TASK << 5;
+		p_proc->task.ldts[1].attr1 = DA_DRW | PRIVILEGE_KRNL << 5;
 
 		/**************寄存器初值**********************************/
-		p_proc->task.regs.cs = ((8 * 0) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
-		p_proc->task.regs.ds = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
-		p_proc->task.regs.es = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
-		p_proc->task.regs.fs = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
-		p_proc->task.regs.ss = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_TASK;
-		p_proc->task.regs.gs = (SELECTOR_KERNEL_GS & SA_RPL_MASK) | RPL_TASK;
-		p_proc->task.regs.eflags = 0x1202; /* IF=1, IOPL=1 */
+		p_proc->task.regs.cs = ((8 * 0) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_KRNL;
+		p_proc->task.regs.ds = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_KRNL;
+		p_proc->task.regs.es = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_KRNL;
+		p_proc->task.regs.fs = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_KRNL;
+		p_proc->task.regs.ss = ((8 * 1) & SA_RPL_MASK & SA_TI_MASK) | SA_TIL | RPL_KRNL;
+		p_proc->task.regs.gs = (SELECTOR_KERNEL_GS & SA_RPL_MASK) | RPL_KRNL;
+		p_proc->task.regs.eflags = 0x0202; /* IF=1, IOPL=1 */
 		// p_proc->task.cr3 在页表初始化中处理
 
 		/**************线性地址布局初始化**********************************/ //	add by visual 2016.5.4
diff --git a/kernel/pagetbl.c b/kernel/pagetbl.c
index 7d53a0a..95e061a 100644
--- a/kernel/pagetbl.c
+++ b/kernel/pagetbl.c
@@ -416,7 +416,7 @@ int sys_mmap(void *uesp)
 	size_t mapsize = get_arg(uesp, 3);
 	if (mapsize % num_4K) return -1;
 	int pid = p_proc_current->task.pid;
-
+	kprintf("[\x1b[32mmmap\x1b[0m] 0x%08X -> 0x%08X, length %X\n", linaddr, phyaddr, mapsize);
 	for (size_t off = 0; off <= mapsize; off += num_4K) {
 		lin_mapping_phy(linaddr + off, phyaddr + off, pid, PG_P | PG_USU | PG_RWW, PG_P | PG_USU | PG_RWW);
 	}
diff --git a/kernel/proc.c b/kernel/proc.c
index 998fbc1..3db9895 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -12,6 +12,7 @@
 #include "proc.h"
 #include "global.h"
 #include "proto.h"
+#include "stdio.h"
 
 /*======================================================================*
                               schedule
@@ -19,35 +20,43 @@
  void schedule()
 {
 	PROCESS* p;
-	int	 greatest_ticks = 0;
-	
-	//Added by xw, 18/4/21
-	if (p_proc_current->task.stat == READY && p_proc_current->task.ticks > 0) {		
-		p_proc_next = p_proc_current;	//added by xw, 18/4/26
-		return;
-	}
-
-	while (!greatest_ticks) 
-	{
-		for (p = proc_table; p < proc_table+NR_PCBS; p++)		//edit by visual 2016.4.5
-		{
-			if (p->task.stat == READY && p->task.ticks > greatest_ticks)  //edit by visual 2016.4.5
-			{
-				greatest_ticks = p->task.ticks;
-				// p_proc_current = p;
-				p_proc_next	= p;	//modified by xw, 18/4/26
-			}
-
-		}
-
-		if (!greatest_ticks) 
-		{
-			for (p = proc_table; p < proc_table+NR_PCBS; p++) //edit by visual 2016.4.5
-			{
-				p->task.ticks = p->task.priority;
-			}
+	for (int i = NEXT(p_proc_current->task.pid, NR_PCBS); i != p_proc_current->task.pid; i = NEXT(i, NR_PCBS)) {
+		if (proc_table[i].task.stat == READY) {
+			p_proc_next = &proc_table[i];
+			return;
 		}
 	}
+	p_proc_next = p_proc_current;
+	kprintf("shit\n");
+
+	// int	 greatest_ticks = 0;
+	// //Added by xw, 18/4/21
+	// if (p_proc_current->task.stat == READY && p_proc_current->task.ticks > 0) {		
+	// 	p_proc_next = p_proc_current;	//added by xw, 18/4/26
+	// 	return;
+	// }
+
+	// while (!greatest_ticks) 
+	// {
+	// 	for (p = proc_table; p < proc_table+NR_PCBS; p++)		//edit by visual 2016.4.5
+	// 	{
+	// 		if (p->task.stat == READY && p->task.ticks > greatest_ticks)  //edit by visual 2016.4.5
+	// 		{
+	// 			greatest_ticks = p->task.ticks;
+	// 			// p_proc_current = p;
+	// 			p_proc_next	= p;	//modified by xw, 18/4/26
+	// 		}
+
+	// 	}
+
+	// 	if (!greatest_ticks) 
+	// 	{
+	// 		for (p = proc_table; p < proc_table+NR_PCBS; p++) //edit by visual 2016.4.5
+	// 		{
+	// 			p->task.ticks = p->task.priority;
+	// 		}
+	// 	}
+	// }
 }
 
 /*======================================================================*
diff --git a/kernel/protect.c b/kernel/protect.c
index 3053472..900e247 100644
--- a/kernel/protect.c
+++ b/kernel/protect.c
@@ -12,6 +12,7 @@
 #include "global.h"
 #include "proto.h"
 #include "string.h"
+#include "stdio.h"
 
 /* 本文件内函数声明 */
 static void init_idt_desc(unsigned char vector, u8 desc_type, int_handler handler, unsigned char privilege);
@@ -264,32 +265,25 @@ void exception_handler(int vec_no, int err_code, int eip, int cs, int eflags)
 								  "#MC Machine Check",
 								  "#XF SIMD Floating-Point Exception"};
 
-	/* 通过打印空格的方式清空屏幕的前五行，并把 disp_pos 清零 */
-	disp_pos = 0;
-	for (i = 0; i < 80 * 5; i++)
-	{
-		printf(" ");
-	}
-	disp_pos = 0;
 
-	printf("\x1b[31;47mException! --> ");
-	printf(err_description[vec_no]);
-	printf("\n\n");
-	printf("EFLAGS:\x1b[m");
-	printf("%d", eflags);
-	printf("\x1b[31;47mCS:\x1b[m");
-	printf("%d", cs);
-	printf("\x1b[31;47mEIP:\x1b[m");
-	printf("%d", eip);
+	kprintf("\x1b[31;47mException! --> ");
+	kprintf(err_description[vec_no]);
+	kprintf("\n\n");
+	kprintf("EFLAGS:\x1b[m");
+	kprintf("%x", eflags);
+	kprintf("\x1b[31;47mCS:\x1b[m");
+	kprintf("%x", cs);
+	kprintf("\x1b[31;47mEIP:\x1b[m");
+	kprintf("%p", eip);
 
 	if (err_code != 0xFFFFFFFF)
 	{
-		printf("\x1b[31;47mError code:\x1b[m");
-		printf("%d", err_code);
+		kprintf("\x1b[31;47mError code:\x1b[m");
+		kprintf("%x", err_code);
 	}
 
 	// added by xw, 18/12/19
-	printf("\n");
+	kprintf("\n");
 
 	// added by xw, 18/12/19
 	p_proc_current->task.stat = KILLED;
@@ -316,7 +310,7 @@ void divide_error_handler()
 
 	while (1)
 	{
-		printf("Loop in divide error handler...\n");
+		kprintf("Loop in divide error handler...\n");
 
 		i = 100;
 		while (--i)
diff --git a/kernel/tty.c b/kernel/tty.c
index 98a0902..36a7fbb 100644
--- a/kernel/tty.c
+++ b/kernel/tty.c
@@ -57,7 +57,24 @@ static int dummy_ioctl(NTTY* tty, u32 cmd, long arg) {return 0;}
 void init_tty_main()
 {
 	NTTY *tty;
-	for (int i = 0; i < 2; ++i)
+	for (int i = 0; i < 1; ++i)
+	{
+		// tty = &ntty_table[i];
+		tty = (NTTY*)K_PHY2LIN(do_kmalloc(sizeof(NTTY)));
+		tty->driver_type = 1; // vga
+							  // tty->input_buf = (void*)do_kmalloc(sizeof(keyboard_buf));
+							  // tty->output_buf = (void*)do_kmalloc(sizeof(vga_buf));
+		tty->input_buf = (keyboard_buf*)K_PHY2LIN(do_kmalloc(sizeof(keyboard_buf)));
+		tty->output_buf = NULL;
+		// vga_tty_init(tty);
+		ps2_tty_init(tty);
+		tty->write = fbcon_tty_write;
+		tty->read = ps2_tty_read;
+		tty->recvbuf = ps2_tty_recvbuf;
+		tty->ioctl = dummy_ioctl;
+		ntty_table[i] = tty;
+	}
+	for (int i = 1; i < 2; ++i)
 	{
 		// tty = &ntty_table[i];
 		tty = (NTTY*)K_PHY2LIN(do_kmalloc(sizeof(NTTY)));
diff --git a/lib/kprintf.c b/lib/kprintf.c
index 9c27eb1..0cc6378 100644
--- a/lib/kprintf.c
+++ b/lib/kprintf.c
@@ -9,8 +9,8 @@
 static void kprintfputch(int ch, int *cnt)
 {
 	write_serial(ch);
-	char _ch = ch;
-	tty_write(cur_ntty, &_ch, 1);
+	// char _ch = ch;
+	// tty_write(cur_ntty, &_ch, 1);
 	(*cnt)++;
 }
 
diff --git a/user/shell_0.c b/user/shell_0.c
index 2f66383..5691b43 100644
--- a/user/shell_0.c
+++ b/user/shell_0.c
@@ -9,9 +9,9 @@
 
 int main(int arg, char *argv[])
 {
-	int stdin = open("dev_tty2", O_RDWR);
-	int stdout = open("dev_tty2", O_RDWR);
-	int stderr = open("dev_tty2", O_RDWR);
+	int stdin = open("dev_tty0", O_RDWR);
+	int stdout = open("dev_tty0", O_RDWR);
+	int stderr = open("dev_tty0", O_RDWR);
 
 	char buf[1024];
 	int pid;
diff --git a/user/test.c b/user/test.c
index 92dccce..8b4e992 100644
--- a/user/test.c
+++ b/user/test.c
@@ -16,10 +16,11 @@ int main(int arg, char *argv[])
 	char buf[1024];
 	int pid;
 	int times = 0;
-	// for (int i = 0; i < 20; ++i)
-	// {
-	// 	printf("test %d\n", i);
-	// }
+	for (int i = 0; i < 50; ++i)
+	{
+		printf("test %d\n", i);
+		for (int j = 0; j < 2000000; ++ j);
+	}
 	// for (int i = 0; i < 2; ++i)
 	// {
 	// 	printf("\x1b[42;31m1111111111");