pts

14 files changed, 565 insertions, 584 deletions

diff --git a/config.mk b/config.mk
index 056f537..7870559 100644
--- a/config.mk
+++ b/config.mk
@@ -161,11 +161,11 @@ AUTOSTACK_OBJS = autostack.o
 #
 # Kernel object files you provide in from kern/
 #
-KERNEL_OBJS = console.o kernel.o loader.o malloc_wrappers.o sync_asm.o \
+KERNEL_OBJS = pts.o kernel.o loader.o malloc_wrappers.o sync_asm.o \
 	mm.o asm_instr.o sched.o sched_asm.o syscall_asm.o interrupt.o \
 	paging.o timer.o interrupt_asm.o usermem.o syscall_process.o \
 	syscall_memory.o syscall_thread.o common.o sync.o syscall_io.o \
-	usermem_asm.o syscall_misc.o kbd.o pv.o hvcall.o toad.o
+	usermem_asm.o syscall_misc.o pv.o hvcall.o toad.o
 
 ###########################################################################
 # WARNING: Do not put **test** programs into the REQPROGS variables.  Your
diff --git a/kern/console.c b/kern/console.c
deleted file mode 100644
index 716ee50..0000000
--- a/kern/console.c
+++ /dev/null
@@ -1,189 +0,0 @@
-/** @file console.c
- *
- *  @brief Console driver implementation.
- *
- *  @author Hanjie Wu (hanjiew)
- *  @bug No functional bugs
- */
-
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <x86/asm.h>
-#include <x86/video_defines.h>
-
-#include <console.h>
-#include <sched.h>
-
-/** index of the register to start displaying cursor */
-#define CRTC_CURSOR_START 10
-/** bit to start displaying cursor */
-#define CURSOR_ENABLE_BIT 0x20
-
-/** pointer to the viedo memory at B800h */
-a_char_on_screen_t (*console_mem)[CONSOLE_WIDTH] =
-    (a_char_on_screen_t(*)[CONSOLE_WIDTH])CONSOLE_MEM_BASE;
-
-/** the char used to produce blank */
-#define BLANK_CH ' '
-/** initial color of the cursor */
-#define DEFAULT_COLOR (FGND_WHITE | BGND_BLACK)
-
-pts_t* active_pts = NULL;
-spl_t pts_lock = SPL_INIT;
-queue_t* all_pts = NULL;
-
-void pts_init(pts_t* pts) {
-    pts->cur_x = pts->cur_y = 0;
-    pts->cur_color = DEFAULT_COLOR;
-    pts->cur_shown = 1;
-    pts->lock = MUTEX_INIT;
-    pts->refcount = 0;
-    queue_insert_head(&all_pts, &pts->pts_link);
-}
-
-/**
- * @brief Move the cursor to a position. Position is checked before calling this
- * function
- * @param x x
- * @param y y
- */
-static inline void move_cursor(pts_t* pts, int x, int y) {
-    pts->cur_x = x;
-    pts->cur_y = y;
-    int old_if = spl_lock(&pts_lock);
-    if (active_pts == pts) {
-        int pos = y * CONSOLE_WIDTH + x;
-        outb(CRTC_IDX_REG, CRTC_CURSOR_LSB_IDX);
-        outb(CRTC_DATA_REG, pos & 0xff);
-        outb(CRTC_IDX_REG, CRTC_CURSOR_MSB_IDX);
-        outb(CRTC_DATA_REG, pos >> 8);
-    }
-    spl_unlock(&pts_lock, old_if);
-}
-
-/**
- * @brief Scroll the console by one line and clean the last line
- */
-static inline void scroll_page(pts_t* pts) {
-    /* move all but last line forward */
-    memmove(pts->mem[0], pts->mem[1],
-            sizeof(a_char_on_screen_t) * CONSOLE_WIDTH * (CONSOLE_HEIGHT - 1));
-    int i;
-    for (i = 0; i < CONSOLE_WIDTH; i++) {
-        pts->mem[CONSOLE_HEIGHT - 1][i] =
-            (a_char_on_screen_t){BLANK_CH, pts->cur_color};
-    }
-    int old_if = spl_lock(&pts_lock);
-    if (active_pts == pts) {
-        memmove(
-            console_mem[0], console_mem[1],
-            sizeof(a_char_on_screen_t) * CONSOLE_WIDTH * (CONSOLE_HEIGHT - 1));
-        int i;
-        for (i = 0; i < CONSOLE_WIDTH; i++) {
-            console_mem[CONSOLE_HEIGHT - 1][i] =
-                (a_char_on_screen_t){BLANK_CH, pts->cur_color};
-        }
-    }
-    spl_unlock(&pts_lock, old_if);
-}
-
-static inline void draw_char(pts_t* pts,
-                             int row,
-                             int col,
-                             a_char_on_screen_t ch) {
-    pts->mem[row][col] = ch;
-    int old_if = spl_lock(&pts_lock);
-    if (active_pts == pts) {
-        console_mem[row][col] = ch;
-    }
-    spl_unlock(&pts_lock, old_if);
-}
-
-int putbyte(char ch) {
-    return pts_putbyte(get_current()->pts, ch);
-}
-
-int pts_putbyte(pts_t* pts, char ch) {
-    if (ch == '\n') {
-        if (pts->cur_y < CONSOLE_HEIGHT - 1) {
-            move_cursor(pts, 0, pts->cur_y + 1);
-        } else {
-            scroll_page(pts);
-            move_cursor(pts, 0, pts->cur_y);
-        }
-        return ch;
-    }
-    if (ch == '\r') {
-        move_cursor(pts, 0, pts->cur_y);
-        return ch;
-    }
-    if (ch == '\b') {
-        if (pts->cur_x > 0) {
-            move_cursor(pts, pts->cur_x - 1, pts->cur_y);
-
-        } else if (pts->cur_y > 0) {
-            move_cursor(pts, CONSOLE_WIDTH - 1, pts->cur_y - 1);
-        }
-        a_char_on_screen_t c = {BLANK_CH, pts->cur_color};
-        draw_char(pts, pts->cur_y, pts->cur_x, c);
-        return ch;
-    }
-    /* save the position where we should show the char */
-    int prev_x = pts->cur_x, prev_y = pts->cur_y;
-    if (pts->cur_x < CONSOLE_WIDTH - 1) {
-        /* move forward */
-        move_cursor(pts, pts->cur_x + 1, pts->cur_y);
-    } else if (pts->cur_y < CONSOLE_HEIGHT - 1) {
-        /* go to next line */
-        move_cursor(pts, 0, pts->cur_y + 1);
-    } else {
-        /* scroll and go to beginning of the line */
-        scroll_page(pts);
-        move_cursor(pts, 0, pts->cur_y);
-        prev_y -= 1;
-    }
-    a_char_on_screen_t c = {ch, pts->cur_color};
-    draw_char(pts, prev_y, prev_x, c);
-    return ch;
-}
-
-void pts_putbytes(pts_t* pts, const char* s, int len) {
-    if (s == NULL || len <= 0) {
-        return;
-    }
-    int i;
-    for (i = 0; i < len; i++) {
-        pts_putbyte(pts, s[i]);
-    }
-}
-
-int pts_set_term_color(pts_t* pts, int color) {
-    if (color > 0xff || color < 0) {
-        return -1;
-    }
-    pts->cur_color = (char)color;
-    return 0;
-}
-
-void pts_get_term_color(pts_t* pts, int* color) {
-    *color = pts->cur_color;
-}
-
-int pts_set_cursor(pts_t* pts, int row, int col) {
-    if (row >= CONSOLE_HEIGHT || row < 0) {
-        return -1;
-    }
-    if (col >= CONSOLE_WIDTH || col < 0) {
-        return -1;
-    }
-    move_cursor(pts, col, row);
-    return 0;
-}
-
-void pts_get_cursor(pts_t* pts, int* row, int* col) {
-    *row = pts->cur_y;
-    *col = pts->cur_x;
-}
diff --git a/kern/hvcall.c b/kern/hvcall.c
index 65f3e42..e1f7f93 100644
--- a/kern/hvcall.c
+++ b/kern/hvcall.c
@@ -24,7 +24,7 @@
 
 #include <asm_instr.h>
 #include <assert.h>
-#include <console.h>
+#include <pts.h>
 #include <loader.h>
 #include <malloc.h>
 #include <mm.h>
diff --git a/kern/inc/console.h b/kern/inc/console.h
index 0d65922..dbfdbb0 100644
--- a/kern/inc/console.h
+++ b/kern/inc/console.h
@@ -1,20 +1,3 @@
-/*
- *
- *  #     #
- *  ##    #   ####    #####     #     ####   ######
- *  # #   #  #    #     #       #    #    #  #
- *  #  #  #  #    #     #       #    #       #####
- *  #   # #  #    #     #       #    #       #
- *  #    ##  #    #     #       #    #    #  #
- *  #     #   ####      #       #     ####   ######
- *
- * Now that it's P3 instead of P1 you are allowed
- * to edit this file if it suits you.
- *
- * Please delete this notice.
- *
- */
-
 /** @file console.h
  *
  *  @brief console functions.
@@ -26,123 +9,6 @@
 #ifndef _CONSOLE_H
 #define _CONSOLE_H
 
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <x86/asm.h>
-#include <x86/video_defines.h>
-
-#include <common.h>
-#include <sync.h>
-
-/**
- * Someone is not satisfied with the type name char_t so we use this
- * to reperesent a char on screen so that nobody will mistake it with 'char'
- */
-typedef struct a_char_on_screen_s {
-    uint8_t ch;    /** char */
-    uint8_t color; /** color */
-} a_char_on_screen_t;
-
-typedef struct pts_s {
-    queue_t pts_link;
-    int refcount;
-    mutex_t lock;
-    a_char_on_screen_t mem[CONSOLE_HEIGHT][CONSOLE_WIDTH];
-    int cur_x;
-    int cur_y;
-    char cur_color;
-    int cur_shown;
-} pts_t;
-
-extern pts_t* active_pts;
-extern spl_t pts_lock;
-
-void pts_init(pts_t* pts);
-
 int putbyte(char ch);
 
-/** @brief Prints character ch at the current location
- *         of the cursor.
- *
- *  If the character is a newline ('\n'), the cursor is
- *  be moved to the beginning of the next line (scrolling if necessary).  If
- *  the character is a carriage return ('\r'), the cursor
- *  is immediately reset to the beginning of the current
- *  line, causing any future output to overwrite any existing
- *  output on the line.  If backsapce ('\b') is encountered,
- *  the previous character is erased.  See the main console.c description
- *  for more backspace behavior.
- *
- *  @param ch the character to print
- *  @return The input character
- */
-int pts_putbyte(pts_t* pts, char ch);
-
-/** @brief Prints the string s, starting at the current
- *         location of the cursor.
- *
- *  If the string is longer than the current line, the
- *  string fills up the current line and then
- *  continues on the next line. If the string exceeds
- *  available space on the entire console, the screen
- *  scrolls up one line, and then the string
- *  continues on the new line.  If '\n', '\r', and '\b' are
- *  encountered within the string, they are handled
- *  as per putbyte. If len is not a positive integer or s
- *  is null, the function has no effect.
- *
- *  @param s The string to be printed.
- *  @param len The length of the string s.
- *  @return Void.
- */
-void pts_putbytes(pts_t* pts, const char* s, int len);
-
-/** @brief Changes the foreground and background color
- *         of future characters printed on the console.
- *
- *  If the color code is invalid, the function has no effect.
- *
- *  @param color The new color code.
- *  @return 0 on success or integer error code less than 0 if
- *          color code is invalid.
- */
-int pts_set_term_color(pts_t* pts, int color);
-
-/** @brief Writes the current foreground and background
- *         color of characters printed on the console
- *         into the argument color.
- *  @param color The address to which the current color
- *         information will be written.
- *  @return Void.
- */
-void pts_get_term_color(pts_t* pts, int* color);
-
-/** @brief Sets the position of the cursor to the
- *         position (row, col).
- *
- *  Subsequent calls to putbytes should cause the console
- *  output to begin at the new position. If the cursor is
- *  currently hidden, a call to set_cursor() does not show
- *  the cursor.
- *
- *  @param row The new row for the cursor.
- *  @param col The new column for the cursor.
- *  @return 0 on success or integer error code less than 0 if
- *          cursor location is invalid.
- */
-int pts_set_cursor(pts_t* pts, int row, int col);
-
-/** @brief Writes the current position of the cursor
- *         into the arguments row and col.
- *  @param row The address to which the current cursor
- *         row will be written.
- *  @param col The address to which the current cursor
- *         column will be written.
- *  @return Void.
- */
-void pts_get_cursor(pts_t* pts, int* row, int* col);
-
-#endif /* _CONSOLE_H */
+#endif
diff --git a/kern/inc/kbd.h b/kern/inc/kbd.h
deleted file mode 100644
index a7350b6..0000000
--- a/kern/inc/kbd.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/** @file kbd.h
- *
- *  @brief keyboard functions.
- *
- *  @author Hanjie Wu (hanjiew)
- *  @bug No functional bugs
- */
-
-#ifndef _KBD_H_
-#define _KBD_H_
-
-#include <common.h>
-#include <sched.h>
-#include <sync.h>
-
-/**
- * @brief read a line to userspace
- * @param len max length to read
- * @param buf buffer
- * @return size on success, -1 on failure
- */
-int do_readline(int len, va_t buf);
-
-/**
- * @brief read a char
- * @return char read
- */
-int do_getchar();
-
-#endif
diff --git a/kern/inc/pts.h b/kern/inc/pts.h
new file mode 100644
index 0000000..c300fb9
--- /dev/null
+++ b/kern/inc/pts.h
@@ -0,0 +1,192 @@
+/*
+ *
+ *  #     #
+ *  ##    #   ####    #####     #     ####   ######
+ *  # #   #  #    #     #       #    #    #  #
+ *  #  #  #  #    #     #       #    #       #####
+ *  #   # #  #    #     #       #    #       #
+ *  #    ##  #    #     #       #    #    #  #
+ *  #     #   ####      #       #     ####   ######
+ *
+ * Now that it's P3 instead of P1 you are allowed
+ * to edit this file if it suits you.
+ *
+ * Please delete this notice.
+ *
+ */
+
+/** @file pts.h
+ *
+ *  @brief console and keyboard functions.
+ *
+ *  @author Hanjie Wu (hanjiew)
+ *  @bug No functional bugs
+ */
+
+#ifndef _PTS_H
+#define _PTS_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <x86/asm.h>
+#include <x86/interrupt_defines.h>
+#include <x86/keyhelp.h>
+#include <x86/video_defines.h>
+
+#include <pv.h>
+#include <sync.h>
+
+/**
+ * Someone is not satisfied with the type name char_t so we use this
+ * to reperesent a char on screen so that nobody will mistake it with 'char'
+ */
+typedef struct a_char_on_screen_s {
+    uint8_t ch;    /** char */
+    uint8_t color; /** color */
+} a_char_on_screen_t;
+
+/** a node in queue of threads requesting keyboard access */
+typedef struct kbd_request_s {
+    thread_t* t;
+    queue_t node;
+} kbd_request_t;
+
+/** size of scancode ring buffer, a big buffer enough for someone pressing
+ * keyboard fast */
+#define KH_RING_SIZE PAGE_SIZE
+/** size of character ring buffer, a big buffer enough for someone pressing
+ * keyboard fast */
+#define CHR_RING_SIZE PAGE_SIZE
+/** maximum readline size */
+#define MAX_READLINE (CHR_RING_SIZE - 1)
+
+typedef struct pts_s {
+    queue_t pts_link;
+    int refcount;
+    mutex_t lock;
+
+    a_char_on_screen_t mem[CONSOLE_HEIGHT][CONSOLE_WIDTH];
+    int cur_x;
+    int cur_y;
+    char cur_color;
+    int cur_shown;
+
+    queue_t* reqs;
+    mutex_t kbd_request_lock;
+    cv_t kbd_request_cv;
+    mutex_t input_lock;
+    cv_t input_cv;
+    unsigned char kh_ring[KH_RING_SIZE];
+    int kh_r_pos;
+    int kh_w_pos;
+    char chr_ring[CHR_RING_SIZE];
+    int chr_r_pos;
+    int chr_w_pos;
+} pts_t;
+
+extern pts_t* active_pts;
+extern spl_t pts_lock;
+
+void pts_init(pts_t* pts);
+
+int putbyte(char ch);
+
+/** @brief Prints character ch at the current location
+ *         of the cursor.
+ *
+ *  If the character is a newline ('\n'), the cursor is
+ *  be moved to the beginning of the next line (scrolling if necessary).  If
+ *  the character is a carriage return ('\r'), the cursor
+ *  is immediately reset to the beginning of the current
+ *  line, causing any future output to overwrite any existing
+ *  output on the line.  If backsapce ('\b') is encountered,
+ *  the previous character is erased.  See the main console.c description
+ *  for more backspace behavior.
+ *
+ *  @param ch the character to print
+ *  @return The input character
+ */
+int pts_putbyte(pts_t* pts, char ch);
+
+/** @brief Prints the string s, starting at the current
+ *         location of the cursor.
+ *
+ *  If the string is longer than the current line, the
+ *  string fills up the current line and then
+ *  continues on the next line. If the string exceeds
+ *  available space on the entire console, the screen
+ *  scrolls up one line, and then the string
+ *  continues on the new line.  If '\n', '\r', and '\b' are
+ *  encountered within the string, they are handled
+ *  as per putbyte. If len is not a positive integer or s
+ *  is null, the function has no effect.
+ *
+ *  @param s The string to be printed.
+ *  @param len The length of the string s.
+ *  @return Void.
+ */
+void pts_putbytes(pts_t* pts, const char* s, int len);
+
+/** @brief Changes the foreground and background color
+ *         of future characters printed on the console.
+ *
+ *  If the color code is invalid, the function has no effect.
+ *
+ *  @param color The new color code.
+ *  @return 0 on success or integer error code less than 0 if
+ *          color code is invalid.
+ */
+int pts_set_term_color(pts_t* pts, int color);
+
+/** @brief Writes the current foreground and background
+ *         color of characters printed on the console
+ *         into the argument color.
+ *  @param color The address to which the current color
+ *         information will be written.
+ *  @return Void.
+ */
+void pts_get_term_color(pts_t* pts, int* color);
+
+/** @brief Sets the position of the cursor to the
+ *         position (row, col).
+ *
+ *  Subsequent calls to putbytes should cause the console
+ *  output to begin at the new position. If the cursor is
+ *  currently hidden, a call to set_cursor() does not show
+ *  the cursor.
+ *
+ *  @param row The new row for the cursor.
+ *  @param col The new column for the cursor.
+ *  @return 0 on success or integer error code less than 0 if
+ *          cursor location is invalid.
+ */
+int pts_set_cursor(pts_t* pts, int row, int col);
+
+/** @brief Writes the current position of the cursor
+ *         into the arguments row and col.
+ *  @param row The address to which the current cursor
+ *         row will be written.
+ *  @param col The address to which the current cursor
+ *         column will be written.
+ *  @return Void.
+ */
+void pts_get_cursor(pts_t* pts, int* row, int* col);
+
+/**
+ * @brief read a line to userspace
+ * @param len max length to read
+ * @param buf buffer
+ * @return size on success, -1 on failure
+ */
+int do_readline(int len, va_t buf);
+
+/**
+ * @brief read a char
+ * @return char read
+ */
+int do_getchar();
+
+#endif /* _PTS_H */
diff --git a/kern/inc/sched.h b/kern/inc/sched.h
index 718fdae..754567e 100644
--- a/kern/inc/sched.h
+++ b/kern/inc/sched.h
@@ -16,7 +16,7 @@
 #include <x86/seg.h>
 
 #include <common.h>
-#include <console.h>
+#include <pts.h>
 #include <paging.h>
 #include <pv.h>
 #include <sync.h>
diff --git a/kern/kbd.c b/kern/kbd.c
deleted file mode 100644
index d933293..0000000
--- a/kern/kbd.c
+++ /dev/null
@@ -1,220 +0,0 @@
-/** @file kbd.c
- *
- *  @brief Keyboard handler implementation.
- *
- *  @author Hanjie Wu (hanjiew)
- *  @bug No functional bugs.
- */
-
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <x86/asm.h>
-#include <x86/interrupt_defines.h>
-#include <x86/keyhelp.h>
-
-#include <console.h>
-#include <interrupt.h>
-#include <kbd.h>
-#include <paging.h>
-#include <pv.h>
-#include <sync.h>
-#include <usermem.h>
-
-/** a node in queue of threads requesting keyboard access */
-typedef struct kbd_request_s {
-    thread_t* t;
-    queue_t node;
-} kbd_request_t;
-
-/** size of scancode ring buffer, a big buffer enough for someone pressing
- * keyboard fast */
-#define KH_RING_SIZE PAGE_SIZE
-/** size of character ring buffer, a big buffer enough for someone pressing
- * keyboard fast */
-#define CHR_RING_SIZE PAGE_SIZE
-/** maximum readline size */
-#define MAX_READLINE (CHR_RING_SIZE - 1)
-
-/** queue of threads requesting keyboard access */
-static queue_t* inputs = NULL;
-
-/** mutex for keyboard request queue */
-static mutex_t kbd_request_lock = MUTEX_INIT;
-/** signal for a thread leaving request queue */
-static cv_t kbd_request_cv = CV_INIT;
-
-/** mutex for new scancode input */
-static mutex_t input_lock = MUTEX_INIT;
-/** signal for new scancode input */
-static cv_t input_cv = CV_INIT;
-
-/** augchar buffer */
-static unsigned char kh_ring[KH_RING_SIZE];
-/** read pointer of augchar ring buffer */
-static int kh_r_pos = 0;
-/** write pointer of augchar ring buffer */
-static int kh_w_pos = 0;
-
-/** character ring buffer */
-static char chr_ring[CHR_RING_SIZE];
-/** read pointer of character ring buffer */
-static int chr_r_pos = 0;
-/** write pointer of character ring buffer */
-static int chr_w_pos = 0;
-
-/**
- * @brief keyboard inturrupt handler
- */
-void kbd_handler_real(stack_frame_t* f) {
-    unsigned char sc = inb(KEYBOARD_PORT);
-    pic_acknowledge(KBD_IRQ);
-    kh_type kh = process_scancode(sc);
-    if (pv_inject_irq(f, KEY_IDT_ENTRY, kh) == 0) {
-        return;
-    }
-    if (KH_HASDATA(kh) && KH_ISMAKE(kh)) {
-        int next_w_pos = (kh_w_pos + 1) % KH_RING_SIZE;
-        if (next_w_pos != kh_r_pos) {
-            kh_ring[kh_w_pos] = kh;
-            kh_w_pos = next_w_pos;
-        }
-    }
-    cv_signal(&input_cv);
-}
-
-/**
- * @brief process scancode until a char is produced
- * @return char produced
- */
-static int sc_process();
-
-/**
- * @brief flush a line to user buffer
- * @param len length of buffer
- * @param buf buffer
- * @return size of chars flushed, -1: buf invalid
- */
-static int flush_line(int len, va_t buf);
-
-int do_readline(int len, va_t buf) {
-    if (len < 0 || len > MAX_READLINE) {
-        return -1;
-    }
-    if (len == 0) {
-        return 0;
-    }
-    kbd_request_t req;
-    req.t = get_current();
-    /* wait until our turn */
-    mutex_lock(&kbd_request_lock);
-    queue_insert_tail(&inputs, &req.node);
-    while (inputs != &req.node) {
-        cv_wait(&kbd_request_cv, &kbd_request_lock);
-    }
-    mutex_unlock(&kbd_request_lock);
-    int should_flush = 0;
-    if (chr_r_pos != chr_w_pos) {
-        int i;
-        for (i = chr_r_pos; i != chr_w_pos; i = (i + 1) % CHR_RING_SIZE) {
-            if (chr_ring[i] == '\n') {
-                should_flush = 1;
-                break;
-            }
-        }
-        /* check if ring is full */
-        if (chr_r_pos == (chr_w_pos + 1) % CHR_RING_SIZE) {
-            should_flush = 1;
-        }
-    }
-    while (should_flush == 0) {
-        /* wait for more chars */
-        char c = sc_process();
-        if (c == '\b') {
-            if (chr_w_pos != chr_r_pos) {
-                putbyte(c);
-                chr_w_pos = (chr_w_pos + CHR_RING_SIZE - 1) % CHR_RING_SIZE;
-            }
-        } else {
-            chr_ring[chr_w_pos] = c;
-            chr_w_pos = (chr_w_pos + 1) % CHR_RING_SIZE;
-            putbyte(c);
-            should_flush =
-                (c == '\n') || (chr_r_pos == (chr_w_pos + 1) % CHR_RING_SIZE);
-        }
-    }
-    int result = flush_line(len, buf);
-    mutex_lock(&kbd_request_lock);
-    queue_detach(&inputs, &req.node);
-    cv_signal(&kbd_request_cv);
-    mutex_unlock(&kbd_request_lock);
-    return result;
-}
-
-int do_getchar() {
-    kbd_request_t req;
-    req.t = get_current();
-    mutex_lock(&kbd_request_lock);
-    queue_insert_tail(&inputs, &req.node);
-    while (inputs != &req.node) {
-        cv_wait(&kbd_request_cv, &kbd_request_lock);
-    }
-    mutex_unlock(&kbd_request_lock);
-    int result;
-    if (chr_r_pos != chr_w_pos) {
-        result = chr_ring[chr_r_pos];
-        chr_r_pos = (chr_r_pos + 1) % CHR_RING_SIZE;
-    } else {
-        result = sc_process();
-    }
-    mutex_lock(&kbd_request_lock);
-    queue_detach(&inputs, &req.node);
-    cv_signal(&kbd_request_cv);
-    mutex_unlock(&kbd_request_lock);
-    return result;
-}
-
-static int flush_line(int len, va_t buf) {
-    int size = 0, i;
-    for (i = chr_r_pos; i != chr_w_pos; i = (i + 1) % CHR_RING_SIZE) {
-        size++;
-        if (chr_ring[i] == '\n') {
-            break;
-        }
-    }
-    if (size > len) {
-        size = len;
-    }
-    int end_pos = (chr_r_pos + size) % CHR_RING_SIZE;
-    if (end_pos > chr_r_pos) {
-        if (copy_to_user(buf, size, &chr_ring[chr_r_pos]) != 0) {
-            return -1;
-        }
-    } else {
-        int size_1 = (CHR_RING_SIZE - chr_r_pos);
-        if (copy_to_user(buf, size_1, &chr_ring[chr_r_pos]) != 0) {
-            return -1;
-        }
-        if (copy_to_user(buf + size_1, end_pos, &chr_ring[0]) != 0) {
-            return -1;
-        }
-    }
-    chr_r_pos = end_pos;
-    return size;
-}
-
-static int sc_process() {
-    while (1) {
-        /* wait for more scancode */
-        mutex_lock(&input_lock);
-        while (kh_r_pos == kh_w_pos) {
-            cv_wait(&input_cv, &input_lock);
-        }
-        kh_type kh = kh_ring[kh_r_pos];
-        kh_r_pos = (kh_r_pos + 1) % KH_RING_SIZE;
-        mutex_unlock(&input_lock);
-        return KH_GETCHAR(kh);
-    }
-}
diff --git a/kern/kernel.c b/kern/kernel.c
index 5599e95..c5b60c7 100644
--- a/kern/kernel.c
+++ b/kern/kernel.c
@@ -24,7 +24,7 @@
 
 #include <assert.h>
 #include <common.h>
-#include <console.h>
+#include <pts.h>
 #include <interrupt.h>
 #include <mm.h>
 #include <paging.h>
diff --git a/kern/pts.c b/kern/pts.c
new file mode 100644
index 0000000..2d51620
--- /dev/null
+++ b/kern/pts.c
@@ -0,0 +1,363 @@
+/** @file console.c
+ *
+ *  @brief Console driver implementation.
+ *
+ *  @author Hanjie Wu (hanjiew)
+ *  @bug No functional bugs
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <x86/asm.h>
+#include <x86/video_defines.h>
+
+#include <interrupt.h>
+#include <paging.h>
+#include <pts.h>
+#include <pv.h>
+#include <sched.h>
+#include <sync.h>
+#include <usermem.h>
+
+/** index of the register to start displaying cursor */
+#define CRTC_CURSOR_START 10
+/** bit to start displaying cursor */
+#define CURSOR_ENABLE_BIT 0x20
+
+/** pointer to the viedo memory at B800h */
+a_char_on_screen_t (*console_mem)[CONSOLE_WIDTH] =
+    (a_char_on_screen_t(*)[CONSOLE_WIDTH])CONSOLE_MEM_BASE;
+
+/** the char used to produce blank */
+#define BLANK_CH ' '
+/** initial color of the cursor */
+#define DEFAULT_COLOR (FGND_WHITE | BGND_BLACK)
+
+pts_t* active_pts = NULL;
+spl_t pts_lock = SPL_INIT;
+queue_t* all_pts = NULL;
+
+void pts_init(pts_t* pts) {
+    pts->cur_x = pts->cur_y = 0;
+    pts->cur_color = DEFAULT_COLOR;
+    pts->cur_shown = 1;
+
+    pts->reqs = NULL;
+    pts->kbd_request_lock = MUTEX_INIT;
+    pts->kbd_request_cv = CV_INIT;
+    pts->input_lock = MUTEX_INIT;
+    pts->input_cv = CV_INIT;
+    pts->kh_r_pos = pts->kh_w_pos = 0;
+    pts->chr_r_pos = pts->chr_w_pos = 0;
+
+    pts->lock = MUTEX_INIT;
+    pts->refcount = 0;
+    queue_insert_head(&all_pts, &pts->pts_link);
+}
+
+/**
+ * @brief Move the cursor to a position. Position is checked before calling this
+ * function
+ * @param x x
+ * @param y y
+ */
+static inline void move_cursor(pts_t* pts, int x, int y) {
+    pts->cur_x = x;
+    pts->cur_y = y;
+    int old_if = spl_lock(&pts_lock);
+    if (active_pts == pts) {
+        int pos = y * CONSOLE_WIDTH + x;
+        outb(CRTC_IDX_REG, CRTC_CURSOR_LSB_IDX);
+        outb(CRTC_DATA_REG, pos & 0xff);
+        outb(CRTC_IDX_REG, CRTC_CURSOR_MSB_IDX);
+        outb(CRTC_DATA_REG, pos >> 8);
+    }
+    spl_unlock(&pts_lock, old_if);
+}
+
+/**
+ * @brief Scroll the console by one line and clean the last line
+ */
+static inline void scroll_page(pts_t* pts) {
+    /* move all but last line forward */
+    memmove(pts->mem[0], pts->mem[1],
+            sizeof(a_char_on_screen_t) * CONSOLE_WIDTH * (CONSOLE_HEIGHT - 1));
+    int i;
+    for (i = 0; i < CONSOLE_WIDTH; i++) {
+        pts->mem[CONSOLE_HEIGHT - 1][i] =
+            (a_char_on_screen_t){BLANK_CH, pts->cur_color};
+    }
+    int old_if = spl_lock(&pts_lock);
+    if (active_pts == pts) {
+        memmove(
+            console_mem[0], console_mem[1],
+            sizeof(a_char_on_screen_t) * CONSOLE_WIDTH * (CONSOLE_HEIGHT - 1));
+        int i;
+        for (i = 0; i < CONSOLE_WIDTH; i++) {
+            console_mem[CONSOLE_HEIGHT - 1][i] =
+                (a_char_on_screen_t){BLANK_CH, pts->cur_color};
+        }
+    }
+    spl_unlock(&pts_lock, old_if);
+}
+
+static inline void draw_char(pts_t* pts,
+                             int row,
+                             int col,
+                             a_char_on_screen_t ch) {
+    pts->mem[row][col] = ch;
+    int old_if = spl_lock(&pts_lock);
+    if (active_pts == pts) {
+        console_mem[row][col] = ch;
+    }
+    spl_unlock(&pts_lock, old_if);
+}
+
+int putbyte(char ch) {
+    return pts_putbyte(get_current()->pts, ch);
+}
+
+int pts_putbyte(pts_t* pts, char ch) {
+    if (ch == '\n') {
+        if (pts->cur_y < CONSOLE_HEIGHT - 1) {
+            move_cursor(pts, 0, pts->cur_y + 1);
+        } else {
+            scroll_page(pts);
+            move_cursor(pts, 0, pts->cur_y);
+        }
+        return ch;
+    }
+    if (ch == '\r') {
+        move_cursor(pts, 0, pts->cur_y);
+        return ch;
+    }
+    if (ch == '\b') {
+        if (pts->cur_x > 0) {
+            move_cursor(pts, pts->cur_x - 1, pts->cur_y);
+
+        } else if (pts->cur_y > 0) {
+            move_cursor(pts, CONSOLE_WIDTH - 1, pts->cur_y - 1);
+        }
+        a_char_on_screen_t c = {BLANK_CH, pts->cur_color};
+        draw_char(pts, pts->cur_y, pts->cur_x, c);
+        return ch;
+    }
+    /* save the position where we should show the char */
+    int prev_x = pts->cur_x, prev_y = pts->cur_y;
+    if (pts->cur_x < CONSOLE_WIDTH - 1) {
+        /* move forward */
+        move_cursor(pts, pts->cur_x + 1, pts->cur_y);
+    } else if (pts->cur_y < CONSOLE_HEIGHT - 1) {
+        /* go to next line */
+        move_cursor(pts, 0, pts->cur_y + 1);
+    } else {
+        /* scroll and go to beginning of the line */
+        scroll_page(pts);
+        move_cursor(pts, 0, pts->cur_y);
+        prev_y -= 1;
+    }
+    a_char_on_screen_t c = {ch, pts->cur_color};
+    draw_char(pts, prev_y, prev_x, c);
+    return ch;
+}
+
+void pts_putbytes(pts_t* pts, const char* s, int len) {
+    if (s == NULL || len <= 0) {
+        return;
+    }
+    int i;
+    for (i = 0; i < len; i++) {
+        pts_putbyte(pts, s[i]);
+    }
+}
+
+int pts_set_term_color(pts_t* pts, int color) {
+    if (color > 0xff || color < 0) {
+        return -1;
+    }
+    pts->cur_color = (char)color;
+    return 0;
+}
+
+void pts_get_term_color(pts_t* pts, int* color) {
+    *color = pts->cur_color;
+}
+
+int pts_set_cursor(pts_t* pts, int row, int col) {
+    if (row >= CONSOLE_HEIGHT || row < 0) {
+        return -1;
+    }
+    if (col >= CONSOLE_WIDTH || col < 0) {
+        return -1;
+    }
+    move_cursor(pts, col, row);
+    return 0;
+}
+
+void pts_get_cursor(pts_t* pts, int* row, int* col) {
+    *row = pts->cur_y;
+    *col = pts->cur_x;
+}
+
+/**
+ * @brief keyboard inturrupt handler
+ */
+void kbd_handler_real(stack_frame_t* f) {
+    unsigned char sc = inb(KEYBOARD_PORT);
+    pic_acknowledge(KBD_IRQ);
+    kh_type kh = process_scancode(sc);
+    if (pv_inject_irq(f, KEY_IDT_ENTRY, kh) == 0) {
+        return;
+    }
+    pts_t* pts = active_pts;
+    if (KH_HASDATA(kh) && KH_ISMAKE(kh)) {
+        int next_w_pos = (pts->kh_w_pos + 1) % KH_RING_SIZE;
+        if (next_w_pos != pts->kh_r_pos) {
+            pts->kh_ring[pts->kh_w_pos] = kh;
+            pts->kh_w_pos = next_w_pos;
+        }
+    }
+    cv_signal(&pts->input_cv);
+}
+
+/**
+ * @brief process scancode until a char is produced
+ * @return char produced
+ */
+static int sc_process(pts_t* pts);
+
+/**
+ * @brief flush a line to user buffer
+ * @param len length of buffer
+ * @param buf buffer
+ * @return size of chars flushed, -1: buf invalid
+ */
+static int flush_line(pts_t* pts, int len, va_t buf);
+
+int do_readline(int len, va_t buf) {
+    if (len < 0 || len > MAX_READLINE) {
+        return -1;
+    }
+    if (len == 0) {
+        return 0;
+    }
+    pts_t* pts = get_current()->pts;
+    kbd_request_t req;
+    req.t = get_current();
+    /* wait until our turn */
+    mutex_lock(&pts->kbd_request_lock);
+    queue_insert_tail(&pts->reqs, &req.node);
+    while (pts->reqs != &req.node) {
+        cv_wait(&pts->kbd_request_cv, &pts->kbd_request_lock);
+    }
+    mutex_unlock(&pts->kbd_request_lock);
+    int should_flush = 0;
+    if (pts->chr_r_pos != pts->chr_w_pos) {
+        int i;
+        for (i = pts->chr_r_pos; i != pts->chr_w_pos;
+             i = (i + 1) % CHR_RING_SIZE) {
+            if (pts->chr_ring[i] == '\n') {
+                should_flush = 1;
+                break;
+            }
+        }
+        /* check if ring is full */
+        if (pts->chr_r_pos == (pts->chr_w_pos + 1) % CHR_RING_SIZE) {
+            should_flush = 1;
+        }
+    }
+    while (should_flush == 0) {
+        /* wait for more chars */
+        char c = sc_process(pts);
+        if (c == '\b') {
+            if (pts->chr_w_pos != pts->chr_r_pos) {
+                pts_putbyte(pts, c);
+                pts->chr_w_pos =
+                    (pts->chr_w_pos + CHR_RING_SIZE - 1) % CHR_RING_SIZE;
+            }
+        } else {
+            pts->chr_ring[pts->chr_w_pos] = c;
+            pts->chr_w_pos = (pts->chr_w_pos + 1) % CHR_RING_SIZE;
+            pts_putbyte(pts, c);
+            should_flush =
+                (c == '\n') ||
+                (pts->chr_r_pos == (pts->chr_w_pos + 1) % CHR_RING_SIZE);
+        }
+    }
+    int result = flush_line(pts, len, buf);
+    mutex_lock(&pts->kbd_request_lock);
+    queue_detach(&pts->reqs, &req.node);
+    cv_signal(&pts->kbd_request_cv);
+    mutex_unlock(&pts->kbd_request_lock);
+    return result;
+}
+
+int do_getchar() {
+    pts_t* pts = get_current()->pts;
+    kbd_request_t req;
+    req.t = get_current();
+    mutex_lock(&pts->kbd_request_lock);
+    queue_insert_tail(&pts->reqs, &req.node);
+    while (pts->reqs != &req.node) {
+        cv_wait(&pts->kbd_request_cv, &pts->kbd_request_lock);
+    }
+    mutex_unlock(&pts->kbd_request_lock);
+    int result;
+    if (pts->chr_r_pos != pts->chr_w_pos) {
+        result = pts->chr_ring[pts->chr_r_pos];
+        pts->chr_r_pos = (pts->chr_r_pos + 1) % CHR_RING_SIZE;
+    } else {
+        result = sc_process(pts);
+    }
+    mutex_lock(&pts->kbd_request_lock);
+    queue_detach(&pts->reqs, &req.node);
+    cv_signal(&pts->kbd_request_cv);
+    mutex_unlock(&pts->kbd_request_lock);
+    return result;
+}
+
+static int flush_line(pts_t* pts, int len, va_t buf) {
+    int size = 0, i;
+    for (i = pts->chr_r_pos; i != pts->chr_w_pos; i = (i + 1) % CHR_RING_SIZE) {
+        size++;
+        if (pts->chr_ring[i] == '\n') {
+            break;
+        }
+    }
+    if (size > len) {
+        size = len;
+    }
+    int end_pos = (pts->chr_r_pos + size) % CHR_RING_SIZE;
+    if (end_pos > pts->chr_r_pos) {
+        if (copy_to_user(buf, size, &pts->chr_ring[pts->chr_r_pos]) != 0) {
+            return -1;
+        }
+    } else {
+        int size_1 = (CHR_RING_SIZE - pts->chr_r_pos);
+        if (copy_to_user(buf, size_1, &pts->chr_ring[pts->chr_r_pos]) != 0) {
+            return -1;
+        }
+        if (copy_to_user(buf + size_1, end_pos, &pts->chr_ring[0]) != 0) {
+            return -1;
+        }
+    }
+    pts->chr_r_pos = end_pos;
+    return size;
+}
+
+static int sc_process(pts_t* pts) {
+    while (1) {
+        /* wait for more scancode */
+        mutex_lock(&pts->input_lock);
+        while (pts->kh_r_pos == pts->kh_w_pos) {
+            cv_wait(&pts->input_cv, &pts->input_lock);
+        }
+        kh_type kh = pts->kh_ring[pts->kh_r_pos];
+        pts->kh_r_pos = (pts->kh_r_pos + 1) % KH_RING_SIZE;
+        mutex_unlock(&pts->input_lock);
+        return KH_GETCHAR(kh);
+    }
+}
diff --git a/kern/sched.c b/kern/sched.c
index 396c31d..35e8a58 100644
--- a/kern/sched.c
+++ b/kern/sched.c
@@ -15,7 +15,7 @@
 #include <x86/seg.h>
 
 #include <asm_instr.h>
-#include <console.h>
+#include <pts.h>
 #include <loader.h>
 #include <malloc.h>
 #include <mm.h>
diff --git a/kern/syscall_io.c b/kern/syscall_io.c
index fafc4cb..6ebc2b5 100644
--- a/kern/syscall_io.c
+++ b/kern/syscall_io.c
@@ -16,8 +16,7 @@
 #include <x86/eflags.h>
 #include <x86/seg.h>
 
-#include <console.h>
-#include <kbd.h>
+#include <pts.h>
 #include <malloc.h>
 #include <mm.h>
 #include <paging.h>
diff --git a/kern/toad.c b/kern/toad.c
index 86ce9c6..96cf60f 100644
--- a/kern/toad.c
+++ b/kern/toad.c
@@ -1,4 +1,4 @@
-#include <console.h>
+#include <pts.h>
 #include <sched.h>
 
 const char toad[] =
diff --git a/kern/usermem.c b/kern/usermem.c
index 2d7c7b6..5e6b1e3 100644
--- a/kern/usermem.c
+++ b/kern/usermem.c
@@ -13,7 +13,7 @@
 #include <x86/asm.h>
 #include <x86/seg.h>
 
-#include <console.h>
+#include <pts.h>
 #include <mm.h>
 #include <paging.h>
 #include <sched.h>