3 files changed, 718 insertions, 77 deletions

diff --git a/sys/dev/cons/cons.c b/sys/dev/cons/cons.c
index 398b6ca..8470a60 100644
--- a/sys/dev/cons/cons.c
+++ b/sys/dev/cons/cons.c
@@ -31,6 +31,8 @@
 #include <sys/types.h>
 #include <sys/ascii.h>
 #include <sys/device.h>
+#include <sys/errno.h>
+#include <sys/panic.h>
 #include <dev/video/fbdev.h>
 #include <dev/cons/font.h>
 #include <dev/cons/cons.h>
@@ -38,6 +40,12 @@
 #include <vm/dynalloc.h>
 #include <string.h>
 
+#define HIDE_CURSOR(SCR) \
+    cons_draw_cursor((SCR), (SCR)->bg)
+
+#define SHOW_CURSOR(SCR) \
+    cons_draw_cursor((SCR), rgb_invert((SCR)->bg))
+
 /* Console background from kconf */
 #if defined(__CONSOLE_BG)
 #define CONSOLE_BG __CONSOLE_BG
@@ -52,29 +60,29 @@
 #define CONSOLE_FG 0x00AA00
 #endif  /* __CONSOLE_FG */
 
-
 struct cons_screen g_root_scr = {0};
 static struct cdevsw cons_cdevsw;
 
-/*
- * Create a chracter descriptor for drawing
- * characters.
- *
- * @c: Character.
- * @fg: Foreground.
- * @bg: Background.
- */
-static inline struct cons_char
-cons_make_char(char c, uint32_t fg, uint32_t bg)
+static void cons_draw_cursor(struct cons_screen *scr, uint32_t color);
+static int cons_handle_special(struct cons_screen *scr, char c);
+
+static uint32_t
+rgb_invert(uint32_t rgb)
 {
-    struct cons_char ch;
+    uint8_t r, g, b;
+    uint32_t ret;
+
+    r = (rgb >> 16) & 0xFF;
+    g = (rgb >> 8) & 0xFF;
+    b = rgb & 0xFF;
 
-    ch.fg = fg;
-    ch.bg = bg;
-    ch.c = c;
-    return ch;
+    ret = (255 - r) << 16;
+    ret |= (255 - g) << 8;
+    ret |= 255 - b;
+    return ret;
 }
 
+
 /*
  * Render a character onto the screen.
  *
@@ -84,10 +92,10 @@ cons_make_char(char c, uint32_t fg, uint32_t bg)
  * @y: Y position of char.
  */
 static void
-cons_draw_char(struct cons_screen *scr, struct cons_char ch,
-                 uint32_t x, uint32_t y)
+cons_draw_char(struct cons_screen *scr, struct cons_char ch)
 {
     size_t idx;
+    uint32_t x, y;
     const uint8_t *glyph;
 
     if (scr->fb_mem == NULL) {
@@ -95,12 +103,131 @@ cons_draw_char(struct cons_screen *scr, struct cons_char ch,
     }
 
     glyph = &CONS_FONT[(int)ch.c*16];
+    x = ch.x;
+    y = ch.y;
+
     for (uint32_t cy = 0; cy < FONT_HEIGHT; ++cy) {
+        idx = fbdev_get_index(&scr->fbdev, x + (FONT_WIDTH - 1), y + cy);
         for (uint32_t cx = 0; cx < FONT_WIDTH; ++cx) {
-            idx = fbdev_get_index(&scr->fbdev, x + (FONT_WIDTH - 1) - cx, y + cy);
-            scr->fb_mem[idx] = ISSET(glyph[cy], BIT(cx)) ? ch.fg : ch.bg;
+            scr->fb_mem[idx--] = ISSET(glyph[cy], BIT(cx)) ? ch.fg : ch.bg;
+        }
+    }
+}
+
+/*
+ * Internal helper - flush console row
+ *
+ * @row: Row to flush.
+ */
+static int
+cons_flush_row(struct cons_screen *scr, uint32_t row)
+{
+    struct cons_buf *bp;
+    struct cons_char cc;
+
+    bp = scr->ob[row];
+    if (ISSET(bp->flags, CONS_BUF_CLEAN)) {
+        return -EIO;
+    }
+
+    for (int j = 0; j < bp->len; ++j) {
+        if (cons_obuf_pop(bp, &cc) != 0) {
+            continue;
         }
+
+        cons_draw_char(scr, cc);
+        bp->flags |= CONS_BUF_CLEAN;
+    }
+
+    return 0;
+}
+
+/*
+ * Internal helper - flush console
+ *
+ */
+static int
+cons_flush(struct cons_screen *scr)
+{
+    for (int i = 0; i < scr->nrows; ++i) {
+        cons_flush_row(scr, i);
     }
+    return 0;
+}
+
+/*
+ * Handle a special character (e.g  "\t", "\n", etc)
+ *
+ * @scr: Screen to handle this on.
+ * @c: Char to handle.
+ *
+ * Returns 0 if handled, otherwise -1.
+ */
+static int
+cons_handle_special(struct cons_screen *scr, char c)
+{
+    struct cons_buf *bp;
+
+    if (scr->ch_col >= scr->ncols - 20) {
+        scr->ch_col = 0;
+        cons_handle_special(scr, '\n');
+    }
+
+    switch (c) {
+    case ASCII_HT:
+        HIDE_CURSOR(scr);
+        scr->curs_col += 4;
+        scr->ch_col += 4;
+        if (scr->ch_col >= scr->ncols - 1) {
+           cons_handle_special(scr, '\n');
+        }
+        SHOW_CURSOR(scr);
+        return 0;
+    case ASCII_NUL:
+        return 0;
+    case ASCII_BS:
+        bp = scr->ob[scr->ch_row];
+        if (bp->head > bp->tail) {
+            --bp->head;
+        }
+
+        HIDE_CURSOR(scr);
+        if (scr->ch_col > 0 && scr->curs_col > 0) {
+            --scr->ch_col;
+            --scr->curs_col;
+        }
+        SHOW_CURSOR(scr);
+        return 0;
+    case ASCII_LF:
+        /* Are we past screen width? */
+        if (scr->ch_row >= scr->nrows - 1) {
+            cons_clear_scr(scr, scr->bg);
+            return 0;
+        }
+
+        HIDE_CURSOR(scr);
+
+        /* Make a newline */
+        cons_flush(scr);
+        ++scr->ch_row;
+        scr->ch_col = 0;
+        cons_flush(scr);
+
+        /* Update cursor */
+        scr->curs_row += 1;
+        scr->curs_col = 0;
+        SHOW_CURSOR(scr);
+        return 0;
+    case ASCII_FF:
+        /*
+         * Fuck what they say, this is now the
+         * "flush" byte ::)
+         */
+        cons_flush(scr);
+        return 0;
+    }
+
+    return -1;
 }
 
 static void
@@ -108,10 +235,16 @@ cons_draw_cursor(struct cons_screen *scr, uint32_t color)
 {
     size_t idx;
 
+    /* Past screen width? */
+    if (scr->curs_col >= scr->ncols) {
+        scr->curs_col = 0;
+        scr->curs_row++;
+    }
+
     for (uint32_t cy = 0; cy < FONT_HEIGHT; ++cy) {
+        idx = fbdev_get_index(&scr->fbdev, scr->curs_col * FONT_WIDTH, (scr->curs_row * FONT_HEIGHT) + cy);
         for (uint32_t cx = 0; cx < FONT_WIDTH; ++cx) {
-            idx = fbdev_get_index(&scr->fbdev, (scr->curs_col * FONT_WIDTH) + cx, (scr->curs_row * FONT_HEIGHT) + cy);
-            scr->fb_mem[idx] = color;
+            scr->fb_mem[idx++] = color;
         }
     }
 }
@@ -122,41 +255,78 @@ cons_draw_cursor(struct cons_screen *scr, uint32_t color)
  * @scr: Screen to clear.
  * @bg: Color to clear it to.
  */
-static void
+void
 cons_clear_scr(struct cons_screen *scr, uint32_t bg)
 {
     struct fbdev fbdev = scr->fbdev;
 
+    cons_flush(scr);
+    HIDE_CURSOR(scr);
+
+    scr->ch_col = 0;
+    scr->ch_row = 0;
+    scr->curs_col = 0;
+    scr->curs_row = 0;
+
     for (size_t i = 0; i < fbdev.height * fbdev.pitch; ++i) {
         scr->fb_mem[i] = bg;
     }
+
+    SHOW_CURSOR(scr);
+
 }
 
 /*
- * Handle a special character (e.g  "\t", "\n", etc)
- *
- * @scr: Screen to handle this on.
- * @c: Char to handle.
+ * Quickly put a character on the screen.
+ * XXX: Does not acquire the screen's lock or show/hide the cursor.
  *
- * Returns 0 if handled, otherwise -1.
+ * @scr: Screen.
+ * @c: Character to draw.
  */
-static int
-cons_handle_special(struct cons_screen *scr, char c)
+static void
+cons_fast_putch(struct cons_screen *scr, char c)
 {
-    switch (c) {
-    case ASCII_LF:
-        /* Make a newline */
+    struct cons_char cc;
+    struct cons_buf *bp;
+    int ansi;
+
+    ansi = ansi_feed(&scr->ansi_s, c);
+    if (ansi > 0) {
+        c = ASCII_NUL;
+    } else if (ansi < 0) {
+        c = ASCII_NUL;
+    }
+
+    /* Handle specials */
+    if (cons_handle_special(scr, c) == 0) {
+        return;
+    }
+
+    /* Create a new character */
+    cc.c = c;
+    cc.fg = scr->fg;
+    cc.bg = scr->bg;
+    cc.x = scr->ch_col * FONT_WIDTH;
+    cc.y = scr->ch_row * FONT_HEIGHT;
+
+    /* Push our new character */
+    bp = scr->ob[scr->ch_row];
+    bp->flags &= ~CONS_BUF_CLEAN;
+    cons_obuf_push(bp, cc);
+    ++scr->ch_col;
+
+    /* Check screen bounds */
+    if (cc.x >= (scr->ncols * FONT_WIDTH) - 1) {
         scr->ch_col = 0;
         ++scr->ch_row;
+    }
 
-        cons_draw_cursor(scr, scr->bg);
+    ++scr->curs_col;
+    if (scr->curs_col > scr->ncols - 1) {
         scr->curs_col = 0;
-        scr->curs_row++;
-        cons_draw_cursor(scr, scr->last_chr.fg);
-        return 0;
+        if (scr->curs_row < scr->nrows)
+            ++scr->curs_row;
     }
-
-    return -1;
 }
 
 /*
@@ -165,19 +335,111 @@ cons_handle_special(struct cons_screen *scr, char c)
 static int
 dev_write(dev_t dev, struct sio_txn *sio, int flags)
 {
-    char *p;
+    cons_putstr(&g_root_scr, sio->buf, sio->len);
+    cons_flush(&g_root_scr);
+    return sio->len;
+}
 
-    p = sio->buf;
-    spinlock_acquire(&g_root_scr.lock);
+/*
+ * Character device function.
+ */
+static int
+dev_read(dev_t dev, struct sio_txn *sio, int flags)
+{
+    struct cons_input input;
+    uint8_t *p;
+    int retval;
+    size_t n;
+
+    p = (uint8_t *)sio->buf;
+    n = sio->len;
+
+    /* Must be a power of two */
+    if ((n & 1) != 0) {
+        return -EFAULT;
+    }
 
-    for (size_t i = 0; i < sio->len; ++i) {
-        cons_putch(&g_root_scr, p[i]);
+    retval = cons_ibuf_pop(&g_root_scr, &input);
+    if (retval < 0) {
+        return -EAGAIN;
     }
 
+    spinlock_acquire(&g_root_scr.lock);
+    for (;;) {
+        /* Buffer too small */
+        if (n == 0) {
+            break;
+        }
+
+        *p++ = input.chr;
+        *p++ = input.scancode;
+        n -= 2;
+
+        /* Try to get the next byte */
+        retval = cons_ibuf_pop(&g_root_scr, &input);
+        if (retval < 0) {
+            break;
+        }
+    }
     spinlock_release(&g_root_scr.lock);
     return sio->len;
 }
 
+static int
+cons_init_bufs(struct cons_screen *scr)
+{
+    struct cons_buf *bp;
+    size_t ob_len;
+
+    scr->ib = cons_new_buf(CONS_BUF_INPUT, scr->ncols);
+    if (g_root_scr.ib == NULL) {
+        panic("out of memory\n");
+    }
+
+    ob_len = sizeof(*scr->ob) * scr->nrows;
+    scr->ob = dynalloc(ob_len);
+
+    /* Allocate all output buffers per line */
+    for (size_t i = 0; i < scr->nrows; ++i) {
+        bp = cons_new_buf(CONS_BUF_OUTPUT, scr->ncols);
+        if (bp == NULL) {
+            panic("out of memory\n");
+        }
+        bp->flags |= CONS_BUF_CLEAN;
+        scr->ob[i] = bp;
+    }
+
+    return 0;
+}
+
+/*
+ * Reset console color.
+ */
+void
+cons_reset_color(struct cons_screen *scr)
+{
+    g_root_scr.fg = CONSOLE_FG;
+    g_root_scr.bg = CONSOLE_BG;
+}
+
+void
+cons_update_color(struct cons_screen *scr, uint32_t fg, uint32_t bg)
+{
+    scr->fg = fg;
+    scr->bg = bg;
+}
+
+void
+cons_reset_cursor(struct cons_screen *scr)
+{
+    HIDE_CURSOR(scr);
+    scr->ch_col = 0;
+    scr->ch_row = 0;
+    scr->curs_col = 0;
+    scr->curs_row = 0;
+    SHOW_CURSOR(scr);
+}
+
 /*
  * Put a character on the screen.
  *
@@ -187,44 +449,38 @@ dev_write(dev_t dev, struct sio_txn *sio, int flags)
 int
 cons_putch(struct cons_screen *scr, char c)
 {
-    struct cons_char cons_chr;
-
-    if (scr->ch_col > scr->ncols) {
-        /* Make a newline as we past the max col */
-        scr->ch_col = 0;
-        ++scr->ch_row;
-    }
+    spinlock_acquire(&scr->lock);
+    HIDE_CURSOR(scr);
 
-    if (scr->curs_row >= scr->nrows) {
-        /* Went over the screen size */
-        /* TODO: Scroll instead of just clearing the screen */
-        scr->ch_col = 0;
-        scr->ch_row = 0;
-        cons_clear_scr(scr, scr->bg);
+    cons_fast_putch(scr, c);
 
-        scr->curs_col = 0;
-        scr->curs_row = 0;
-        cons_draw_cursor(scr, scr->last_chr.fg);
-    }
+    SHOW_CURSOR(scr);
+    spinlock_release(&scr->lock);
+    return 0;
+}
 
-    /*
-     * If this is a special char that we can handle
-     * then handle it and return.
-     */
-    if (cons_handle_special(scr, c) == 0) {
-        return 0;
-    }
+/*
+ * Put a string on the screen.
+ *
+ * @scr: Screen.
+ * @s: String to draw.
+ * @l: Length of s.
+ */
+int
+cons_putstr(struct cons_screen *scr, const char *s, size_t len)
+{
+    const char *p = s;
 
-    cons_chr = cons_make_char(c, scr->fg, scr->bg);
-    scr->last_chr = cons_chr;
+    spinlock_acquire(&scr->lock);
+    HIDE_CURSOR(scr);
 
-    /* Draw cursor and character */
-    scr->curs_col++;
-    cons_draw_cursor(scr, scr->last_chr.fg);
-    cons_draw_char(scr, cons_chr, scr->ch_col * FONT_WIDTH,
-        scr->ch_row * FONT_HEIGHT);
+    while (len--) {
+        cons_fast_putch(scr, *p);
+        ++p;
+    }
 
-    ++scr->ch_col;
+    SHOW_CURSOR(scr);
+    spinlock_release(&scr->lock);
     return 0;
 }
 
@@ -233,6 +489,8 @@ cons_init(void)
 {
     struct fbdev fbdev = fbdev_get();
 
+    g_root_scr.ch_col = 0;
+    g_root_scr.ch_row = 0;
     g_root_scr.fg = CONSOLE_FG;
     g_root_scr.bg = CONSOLE_BG;
     g_root_scr.fb_mem = fbdev.mem;
@@ -240,6 +498,8 @@ cons_init(void)
     g_root_scr.ncols = fbdev.width / FONT_WIDTH;
     g_root_scr.fbdev = fbdev;
     memset(&g_root_scr.lock, 0, sizeof(g_root_scr.lock));
+    cons_init_bufs(&g_root_scr);
+    SHOW_CURSOR(&g_root_scr);
 }
 
 /*
@@ -267,6 +527,6 @@ cons_expose(void)
 }
 
 static struct cdevsw cons_cdevsw = {
-    .read = noread,
+    .read = dev_read,
     .write = dev_write
 };
diff --git a/sys/dev/cons/cons_ansi.c b/sys/dev/cons/cons_ansi.c
new file mode 100644
index 0000000..ab1f22a
--- /dev/null
+++ b/sys/dev/cons/cons_ansi.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/cdefs.h>
+#include <dev/cons/cons.h>
+#include <dev/cons/ansi.h>
+#include <string.h>
+
+__always_inline static inline bool
+is_valid_color(int c)
+{
+    return c >= '0' && c <= '7';
+}
+
+static inline void
+ansi_reset(struct ansi_state *statep)
+{
+    memset(statep, 0, sizeof(*statep));
+}
+
+/*
+ * Feed a byte into the ANSI escape sequence
+ * state machine.
+ *
+ * @statep: State machine pointer.
+ * @c: Byte to feed.
+ *
+ * On success, `c' is returned. On failure,
+ * 0 is returned. Values less than 0 indicate
+ * success with console attributes updated
+ * (ANSI_UPDATE_*).
+ */
+int
+ansi_feed(struct ansi_state *statep, char c)
+{
+    /* Standard colors */
+    static uint32_t colortab[] = {
+        ANSI_BLACK, ANSI_RED,
+        ANSI_GREEN, ANSI_YELLOW,
+        ANSI_BLUE, ANSI_MAGENTA,
+        ANSI_CYAN, ANSI_WHITE
+    };
+
+    /*
+     * Handle the control sequence introducer
+     * bytes.
+     */
+    switch (statep->csi) {
+    case 0: /* '\033' */
+        if (c != '\033') {
+            return 0;
+        }
+        statep->csi = 1;
+        statep->prev = c;
+        return c;
+    case 1: /* '[' */
+        if (c != '[') {
+            ansi_reset(statep);
+            return 0;
+        }
+        statep->csi = 2;
+        statep->prev = c;
+        return c;
+    case 2:
+        if (c == 'H') {
+            cons_clear_scr(&g_root_scr, g_root_scr.bg);
+            return ANSI_UPDATE_CURSOR;
+        }
+        break;
+    }
+
+    if (!statep->set_fg && !statep->set_bg) {
+        /* Reset attributes? */
+        if (statep->reset_color) {
+            ansi_reset(statep);
+            cons_reset_color(&g_root_scr);
+            return ANSI_UPDATE_COLOR;
+        }
+
+        /* Mark attributes to be reset? */
+        if (c == '0') {
+            statep->reset_color = 1;
+            statep->prev = c;
+            return c;
+        }
+
+        /* Expect foreground */
+        if (c != '3') {
+            ansi_reset(statep);
+            return 0;
+        }
+        statep->set_fg = 1;
+        statep->prev = c;
+        return c;
+    }
+
+    if (statep->set_fg && c != ';') {
+        /* Make sure this is valid */
+        if (!is_valid_color(c)) {
+            ansi_reset(statep);
+            return 0;
+        }
+
+        /* Set the foreground */
+        statep->fg = colortab[c - '0'];
+        statep->set_bg = 1;
+        statep->set_fg = 0;
+        statep->prev = c;
+        return c;
+    }
+
+    if (statep->set_bg) {
+        if (c == ';') {
+            statep->prev = c;
+            return c;
+        }
+
+        /* Expect '4' after ';' */
+        if (statep->prev == ';' && c != '4') {
+            ansi_reset(statep);
+            return 0;
+        }
+
+        if (c == 'm') {
+            cons_update_color(&g_root_scr, statep->fg, statep->bg);
+            ansi_reset(statep);
+            return ANSI_UPDATE_COLOR;
+        }
+
+        /* Make sure this is valid */
+        if (!is_valid_color(c)) {
+            ansi_reset(statep);
+            return 0;
+        }
+
+        /* Set the background */
+        statep->bg = colortab[c - '0'];
+        statep->prev = c;
+        return c;
+    }
+
+    ansi_reset(statep);
+    return 0;
+}
diff --git a/sys/dev/cons/cons_buf.c b/sys/dev/cons/cons_buf.c
new file mode 100644
index 0000000..84a38ce
--- /dev/null
+++ b/sys/dev/cons/cons_buf.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <dev/cons/consvar.h>
+#include <dev/cons/cons.h>
+#include <vm/dynalloc.h>
+#include <string.h>
+#include <assert.h>
+
+/*
+ * Create a new console buffer.
+ *
+ * @type: Buffer type (CONS_BUF_*)
+ * @len: Max length of buffer.
+ */
+struct cons_buf *
+cons_new_buf(uint8_t type, size_t len)
+{
+    struct cons_buf *bp;
+    size_t alloc_len;
+
+    if ((bp = dynalloc(sizeof(*bp))) == NULL) {
+        return NULL;
+    }
+
+    memset(bp, 0, sizeof(*bp));
+    bp->type = type;
+    bp->len = len;
+
+    /* Create the actual buffers now */
+    switch (type) {
+    case CONS_BUF_INPUT:
+        alloc_len = sizeof(*bp->ibuf) * len;
+        bp->ibuf = dynalloc(alloc_len);
+        break;
+    case CONS_BUF_OUTPUT:
+        alloc_len = sizeof(*bp->obuf) * len;
+        bp->obuf = dynalloc(alloc_len);
+        break;
+    }
+
+    return bp;
+}
+
+/*
+ * Push a character to a console output
+ * buffer.
+ *
+ * @bp: Pointer to console buffer.
+ * @c: Character to push.
+ */
+int
+cons_obuf_push(struct cons_buf *bp, struct cons_char c)
+{
+    uint8_t next;
+    int retval = 0;
+
+    if (bp == NULL) {
+        return -EINVAL;
+    }
+
+    spinlock_acquire(&bp->lock);
+    __assert(bp->type == CONS_BUF_OUTPUT);
+    next = bp->head + 1;
+    if (next > bp->len) {
+        retval = -ENOSPC;
+        goto done;
+    }
+
+    bp->obuf[bp->head] = c;
+    bp->head = next;
+
+done:
+    spinlock_release(&bp->lock);
+    return retval;
+}
+
+/*
+ * Pop a character from the console
+ * buffer.
+ *
+ * @bp: Pointer to console buffer.
+ * @res: Result is written here.
+ */
+int
+cons_obuf_pop(struct cons_buf *bp, struct cons_char *res)
+{
+    uint8_t next;
+    int retval = 0;
+
+    if (bp == NULL || res == NULL) {
+        return -EINVAL;
+    }
+
+    __assert(bp->type == CONS_BUF_OUTPUT);
+    spinlock_acquire(&bp->lock);
+
+    /* Do we have any data left? */
+    if (bp->head == bp->tail) {
+        bp->head = 0;
+        bp->tail = 0;
+        retval = -EAGAIN;
+        goto done;
+    }
+
+    next = bp->tail + 1;
+    if (next > bp->len) {
+        next = 0;
+    }
+
+    *res = bp->obuf[bp->tail];
+    bp->tail = next;
+
+done:
+    spinlock_release(&bp->lock);
+    return retval;
+}
+
+int
+cons_ibuf_push(struct cons_screen *scr, struct cons_input in)
+{
+    struct cons_buf *bp;
+    uint8_t head_next;
+    int retval = 0;
+
+    if (scr == NULL) {
+        return -EINVAL;
+    }
+
+    bp = scr->ib;
+    spinlock_acquire(&bp->lock);
+    __assert(bp->type == CONS_BUF_INPUT);
+
+    head_next = bp->head + 1;
+    if (head_next > bp->len) {
+        retval = -ENOSPC;
+        goto done;
+    }
+
+    bp->ibuf[bp->head] = in;
+    bp->head = head_next;
+
+done:
+    spinlock_release(&bp->lock);
+    return retval;
+}
+
+int
+cons_ibuf_pop(struct cons_screen *scr, struct cons_input *res)
+{
+    uint8_t tail_next;
+    struct cons_buf *bp;
+    int retval = 0;
+
+    if (scr == NULL || res == NULL) {
+        return -EINVAL;
+    }
+
+    bp = scr->ib;
+    __assert(bp->type == CONS_BUF_INPUT);
+    spinlock_acquire(&bp->lock);
+
+    /* Do we have any data left? */
+    if (bp->head == bp->tail) {
+        bp->head = 0;
+        bp->tail = 0;
+        retval = -EAGAIN;
+        goto done;
+    }
+
+    tail_next = bp->tail + 1;
+    if (tail_next > bp->len) {
+        tail_next = 0;
+    }
+
+    *res = bp->ibuf[bp->tail];
+    bp->tail = tail_next;
+
+done:
+    spinlock_release(&bp->lock);
+    return retval;
+}