Archipelago » qemu

/*

 * QEMU graphical console

 *

 * Copyright (c) 2004 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "vl.h"

//#define DEBUG_CONSOLE

#define DEFAULT_BACKSCROLL 512

#define MAX_CONSOLES 12

#define QEMU_RGBA(r, g, b, a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))

#define QEMU_RGB(r, g, b) QEMU_RGBA(r, g, b, 0xff)

typedef struct TextAttributes {

    uint8_t fgcol:4;

    uint8_t bgcol:4;

    uint8_t bold:1;

    uint8_t uline:1;

    uint8_t blink:1;

    uint8_t invers:1;

    uint8_t unvisible:1;

} TextAttributes;

typedef struct TextCell {

    uint8_t ch;

    TextAttributes t_attrib;

} TextCell;

#define MAX_ESC_PARAMS 3

enum TTYState {

    TTY_STATE_NORM,

    TTY_STATE_ESC,

    TTY_STATE_CSI,

};

typedef struct QEMUFIFO {

    uint8_t *buf;

    int buf_size;

    int count, wptr, rptr;

} QEMUFIFO;

int qemu_fifo_write(QEMUFIFO *f, const uint8_t *buf, int len1)

{

    int l, len;

    l = f->buf_size - f->count;

    if (len1 > l)

        len1 = l;

    len = len1;

    while (len > 0) {

        l = f->buf_size - f->wptr;

        if (l > len)

            l = len;

        memcpy(f->buf + f->wptr, buf, l);

        f->wptr += l;

        if (f->wptr >= f->buf_size)

            f->wptr = 0;

        buf += l;

        len -= l;

    }

    f->count += len1;

    return len1;

}

int qemu_fifo_read(QEMUFIFO *f, uint8_t *buf, int len1)

{

    int l, len;

    if (len1 > f->count)

        len1 = f->count;

    len = len1;

    while (len > 0) {

        l = f->buf_size - f->rptr;

        if (l > len)

            l = len;

        memcpy(buf, f->buf + f->rptr, l);

        f->rptr += l;

        if (f->rptr >= f->buf_size)

            f->rptr = 0;

        buf += l;

        len -= l;

    }

    f->count -= len1;

    return len1;

}

typedef enum {

    GRAPHIC_CONSOLE,

    TEXT_CONSOLE,

    TEXT_CONSOLE_FIXED_SIZE

} console_type_t;

/* ??? This is mis-named.

   It is used for both text and graphical consoles.  */

struct TextConsole {

    console_type_t console_type;

    DisplayState *ds;

    /* Graphic console state.  */

    vga_hw_update_ptr hw_update;

    vga_hw_invalidate_ptr hw_invalidate;

    vga_hw_screen_dump_ptr hw_screen_dump;

    void *hw;

    int g_width, g_height;

    int width;

    int height;

    int total_height;

    int backscroll_height;

    int x, y;

    int x_saved, y_saved;

    int y_displayed;

    int y_base;

    TextAttributes t_attrib_default; /* default text attributes */

    TextAttributes t_attrib; /* currently active text attributes */

    TextCell *cells;

    enum TTYState state;

    int esc_params[MAX_ESC_PARAMS];

    int nb_esc_params;

    CharDriverState *chr;

    /* fifo for key pressed */

    QEMUFIFO out_fifo;

    uint8_t out_fifo_buf[16];

    QEMUTimer *kbd_timer;

};

static TextConsole *active_console;

static TextConsole *consoles[MAX_CONSOLES];

static int nb_consoles = 0;

void vga_hw_update(void)

{

    if (active_console && active_console->hw_update)

        active_console->hw_update(active_console->hw);

}

void vga_hw_invalidate(void)

{

    if (active_console->hw_invalidate)

        active_console->hw_invalidate(active_console->hw);

}

void vga_hw_screen_dump(const char *filename)

{

    /* There is currently no was of specifying which screen we want to dump,

       so always dump the dirst one.  */

    if (consoles[0]->hw_screen_dump)

        consoles[0]->hw_screen_dump(consoles[0]->hw, filename);

}

/* convert a RGBA color to a color index usable in graphic primitives */

static unsigned int vga_get_color(DisplayState *ds, unsigned int rgba)

{

    unsigned int r, g, b, color;

    switch(ds->depth) {

#if 0

    case 8:

        r = (rgba >> 16) & 0xff;

        g = (rgba >> 8) & 0xff;

        b = (rgba) & 0xff;

        color = (rgb_to_index[r] * 6 * 6) +

            (rgb_to_index[g] * 6) +

            (rgb_to_index[b]);

        break;

#endif

    case 15:

        r = (rgba >> 16) & 0xff;

        g = (rgba >> 8) & 0xff;

        b = (rgba) & 0xff;

        color = ((r >> 3) << 10) | ((g >> 3) << 5) | (b >> 3);

        break;

    case 16:

        r = (rgba >> 16) & 0xff;

        g = (rgba >> 8) & 0xff;

        b = (rgba) & 0xff;

        color = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3);

        break;

    case 32:

    default:

        color = rgba;

        break;

    }

    return color;

}

static void vga_fill_rect (DisplayState *ds,

                           int posx, int posy, int width, int height, uint32_t color)

{

    uint8_t *d, *d1;

    int x, y, bpp;

    bpp = (ds->depth + 7) >> 3;

    d1 = ds->data +

        ds->linesize * posy + bpp * posx;

    for (y = 0; y < height; y++) {

        d = d1;

        switch(bpp) {

        case 1:

            for (x = 0; x < width; x++) {

                *((uint8_t *)d) = color;

                d++;

            }

            break;

        case 2:

            for (x = 0; x < width; x++) {

                *((uint16_t *)d) = color;

                d += 2;

            }

            break;

        case 4:

            for (x = 0; x < width; x++) {

                *((uint32_t *)d) = color;

                d += 4;

            }

            break;

        }

        d1 += ds->linesize;

    }

}

/* copy from (xs, ys) to (xd, yd) a rectangle of size (w, h) */

static void vga_bitblt(DisplayState *ds, int xs, int ys, int xd, int yd, int w, int h)

{

    const uint8_t *s;

    uint8_t *d;

    int wb, y, bpp;

    bpp = (ds->depth + 7) >> 3;

    wb = w * bpp;

    if (yd <= ys) {

        s = ds->data +

            ds->linesize * ys + bpp * xs;

        d = ds->data +

            ds->linesize * yd + bpp * xd;

        for (y = 0; y < h; y++) {

            memmove(d, s, wb);

            d += ds->linesize;

            s += ds->linesize;

        }

    } else {

        s = ds->data +

            ds->linesize * (ys + h - 1) + bpp * xs;

        d = ds->data +

            ds->linesize * (yd + h - 1) + bpp * xd;

       for (y = 0; y < h; y++) {

            memmove(d, s, wb);

            d -= ds->linesize;

            s -= ds->linesize;

        }

    }

}

/***********************************************************/

/* basic char display */

#define FONT_HEIGHT 16

#define FONT_WIDTH 8

#include "vgafont.h"

#define cbswap_32(__x) \

((uint32_t)( \

                (((uint32_t)(__x) & (uint32_t)0x000000ffUL) << 24) | \

                (((uint32_t)(__x) & (uint32_t)0x0000ff00UL) <<  8) | \

                (((uint32_t)(__x) & (uint32_t)0x00ff0000UL) >>  8) | \

                (((uint32_t)(__x) & (uint32_t)0xff000000UL) >> 24) ))

#ifdef WORDS_BIGENDIAN

#define PAT(x) x

#else

#define PAT(x) cbswap_32(x)

#endif

static const uint32_t dmask16[16] = {

    PAT(0x00000000),

    PAT(0x000000ff),

    PAT(0x0000ff00),

    PAT(0x0000ffff),

    PAT(0x00ff0000),

    PAT(0x00ff00ff),

    PAT(0x00ffff00),

    PAT(0x00ffffff),

    PAT(0xff000000),

    PAT(0xff0000ff),

    PAT(0xff00ff00),

    PAT(0xff00ffff),

    PAT(0xffff0000),

    PAT(0xffff00ff),

    PAT(0xffffff00),

    PAT(0xffffffff),

};

static const uint32_t dmask4[4] = {

    PAT(0x00000000),

    PAT(0x0000ffff),

    PAT(0xffff0000),

    PAT(0xffffffff),

};

static uint32_t color_table[2][8];

enum color_names {

    COLOR_BLACK   = 0,

    COLOR_RED     = 1,

    COLOR_GREEN   = 2,

    COLOR_YELLOW  = 3,

    COLOR_BLUE    = 4,

    COLOR_MAGENTA = 5,

    COLOR_CYAN    = 6,

    COLOR_WHITE   = 7

};

static const uint32_t color_table_rgb[2][8] = {

    {   /* dark */

        QEMU_RGB(0x00, 0x00, 0x00),  /* black */

        QEMU_RGB(0xaa, 0x00, 0x00),  /* red */

        QEMU_RGB(0x00, 0xaa, 0x00),  /* green */

        QEMU_RGB(0xaa, 0xaa, 0x00),  /* yellow */

        QEMU_RGB(0x00, 0x00, 0xaa),  /* blue */

        QEMU_RGB(0xaa, 0x00, 0xaa),  /* magenta */

        QEMU_RGB(0x00, 0xaa, 0xaa),  /* cyan */

        QEMU_RGB(0xaa, 0xaa, 0xaa),  /* white */

    },

    {   /* bright */

        QEMU_RGB(0x00, 0x00, 0x00),  /* black */

        QEMU_RGB(0xff, 0x00, 0x00),  /* red */

        QEMU_RGB(0x00, 0xff, 0x00),  /* green */

        QEMU_RGB(0xff, 0xff, 0x00),  /* yellow */

        QEMU_RGB(0x00, 0x00, 0xff),  /* blue */

        QEMU_RGB(0xff, 0x00, 0xff),  /* magenta */

        QEMU_RGB(0x00, 0xff, 0xff),  /* cyan */

        QEMU_RGB(0xff, 0xff, 0xff),  /* white */

    }

};

static inline unsigned int col_expand(DisplayState *ds, unsigned int col)

{

    switch(ds->depth) {

    case 8:

        col |= col << 8;

        col |= col << 16;

        break;

    case 15:

    case 16:

        col |= col << 16;

        break;

    default:

        break;

    }

    return col;

}

#ifdef DEBUG_CONSOLE

static void console_print_text_attributes(TextAttributes *t_attrib, char ch)

{

    if (t_attrib->bold) {

        printf("b");

    } else {

        printf(" ");

    }

    if (t_attrib->uline) {

        printf("u");

    } else {

        printf(" ");

    }

    if (t_attrib->blink) {

        printf("l");

    } else {

        printf(" ");

    }

    if (t_attrib->invers) {

        printf("i");

    } else {

        printf(" ");

    }

    if (t_attrib->unvisible) {

        printf("n");

    } else {

        printf(" ");

    }

    printf(" fg: %d bg: %d ch:'%2X' '%c'\n", t_attrib->fgcol, t_attrib->bgcol, ch, ch);

}

#endif

static void vga_putcharxy(DisplayState *ds, int x, int y, int ch,

                          TextAttributes *t_attrib)

{

    uint8_t *d;

    const uint8_t *font_ptr;

    unsigned int font_data, linesize, xorcol, bpp;

    int i;

    unsigned int fgcol, bgcol;

#ifdef DEBUG_CONSOLE

    printf("x: %2i y: %2i", x, y);

    console_print_text_attributes(t_attrib, ch);

#endif

    if (t_attrib->invers) {

        bgcol = color_table[t_attrib->bold][t_attrib->fgcol];

        fgcol = color_table[t_attrib->bold][t_attrib->bgcol];

    } else {

        fgcol = color_table[t_attrib->bold][t_attrib->fgcol];

        bgcol = color_table[t_attrib->bold][t_attrib->bgcol];

    }

    bpp = (ds->depth + 7) >> 3;

    d = ds->data +

        ds->linesize * y * FONT_HEIGHT + bpp * x * FONT_WIDTH;

    linesize = ds->linesize;

    font_ptr = vgafont16 + FONT_HEIGHT * ch;

    xorcol = bgcol ^ fgcol;

    switch(ds->depth) {

    case 8:

        for(i = 0; i < FONT_HEIGHT; i++) {

            font_data = *font_ptr++;

            if (t_attrib->uline

                && ((i == FONT_HEIGHT - 2) || (i == FONT_HEIGHT - 3))) {

                font_data = 0xFFFF;

            }

            ((uint32_t *)d)[0] = (dmask16[(font_data >> 4)] & xorcol) ^ bgcol;

            ((uint32_t *)d)[1] = (dmask16[(font_data >> 0) & 0xf] & xorcol) ^ bgcol;

            d += linesize;

        }

        break;

    case 16:

    case 15:

        for(i = 0; i < FONT_HEIGHT; i++) {

            font_data = *font_ptr++;

            if (t_attrib->uline

                && ((i == FONT_HEIGHT - 2) || (i == FONT_HEIGHT - 3))) {

                font_data = 0xFFFF;

            }

            ((uint32_t *)d)[0] = (dmask4[(font_data >> 6)] & xorcol) ^ bgcol;

            ((uint32_t *)d)[1] = (dmask4[(font_data >> 4) & 3] & xorcol) ^ bgcol;

            ((uint32_t *)d)[2] = (dmask4[(font_data >> 2) & 3] & xorcol) ^ bgcol;

            ((uint32_t *)d)[3] = (dmask4[(font_data >> 0) & 3] & xorcol) ^ bgcol;

            d += linesize;

        }

        break;

    case 32:

        for(i = 0; i < FONT_HEIGHT; i++) {

            font_data = *font_ptr++;

            if (t_attrib->uline && ((i == FONT_HEIGHT - 2) || (i == FONT_HEIGHT - 3))) {

                font_data = 0xFFFF;

            }

            ((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;

            ((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[2] = (-((font_data >> 5) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[3] = (-((font_data >> 4) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[4] = (-((font_data >> 3) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[5] = (-((font_data >> 2) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[6] = (-((font_data >> 1) & 1) & xorcol) ^ bgcol;

            ((uint32_t *)d)[7] = (-((font_data >> 0) & 1) & xorcol) ^ bgcol;

            d += linesize;

        }

        break;

    }

}

static void text_console_resize(TextConsole *s)

{

    TextCell *cells, *c, *c1;

    int w1, x, y, last_width;

    last_width = s->width;

    s->width = s->g_width / FONT_WIDTH;

    s->height = s->g_height / FONT_HEIGHT;

    w1 = last_width;

    if (s->width < w1)

        w1 = s->width;

    cells = qemu_malloc(s->width * s->total_height * sizeof(TextCell));

    for(y = 0; y < s->total_height; y++) {

        c = &cells[y * s->width];

        if (w1 > 0) {

            c1 = &s->cells[y * last_width];

            for(x = 0; x < w1; x++) {

                *c++ = *c1++;

            }

        }

        for(x = w1; x < s->width; x++) {

            c->ch = ' ';

            c->t_attrib = s->t_attrib_default;

            c++;

        }

    }

    qemu_free(s->cells);

    s->cells = cells;

}

static void update_xy(TextConsole *s, int x, int y)

{

    TextCell *c;

    int y1, y2;

    if (s == active_console) {

        y1 = (s->y_base + y) % s->total_height;

        y2 = y1 - s->y_displayed;

        if (y2 < 0)

            y2 += s->total_height;

        if (y2 < s->height) {

            c = &s->cells[y1 * s->width + x];

            vga_putcharxy(s->ds, x, y2, c->ch,

                          &(c->t_attrib));

            dpy_update(s->ds, x * FONT_WIDTH, y2 * FONT_HEIGHT,

                       FONT_WIDTH, FONT_HEIGHT);

        }

    }

}

static void console_show_cursor(TextConsole *s, int show)

{

    TextCell *c;

    int y, y1;

    if (s == active_console) {

        int x = s->x;

        if (x >= s->width) {

            x = s->width - 1;

        }

        y1 = (s->y_base + s->y) % s->total_height;

        y = y1 - s->y_displayed;

        if (y < 0)

            y += s->total_height;

        if (y < s->height) {

            c = &s->cells[y1 * s->width + x];

            if (show) {

                TextAttributes t_attrib = s->t_attrib_default;

                t_attrib.invers = !(t_attrib.invers); /* invert fg and bg */

                vga_putcharxy(s->ds, x, y, c->ch, &t_attrib);

            } else {

                vga_putcharxy(s->ds, x, y, c->ch, &(c->t_attrib));

            }

            dpy_update(s->ds, x * FONT_WIDTH, y * FONT_HEIGHT,

                       FONT_WIDTH, FONT_HEIGHT);

        }

    }

}

static void console_refresh(TextConsole *s)

{

    TextCell *c;

    int x, y, y1;

    if (s != active_console)

        return;

    vga_fill_rect(s->ds, 0, 0, s->ds->width, s->ds->height,

                  color_table[0][COLOR_BLACK]);

    y1 = s->y_displayed;

    for(y = 0; y < s->height; y++) {

        c = s->cells + y1 * s->width;

        for(x = 0; x < s->width; x++) {

            vga_putcharxy(s->ds, x, y, c->ch,

                          &(c->t_attrib));

            c++;

        }

        if (++y1 == s->total_height)

            y1 = 0;

    }

    dpy_update(s->ds, 0, 0, s->ds->width, s->ds->height);

    console_show_cursor(s, 1);

}

static void console_scroll(int ydelta)

{

    TextConsole *s;

    int i, y1;

    s = active_console;

    if (!s || (s->console_type == GRAPHIC_CONSOLE))

        return;

    if (ydelta > 0) {

        for(i = 0; i < ydelta; i++) {

            if (s->y_displayed == s->y_base)

                break;

            if (++s->y_displayed == s->total_height)

                s->y_displayed = 0;

        }

    } else {

        ydelta = -ydelta;

        i = s->backscroll_height;

        if (i > s->total_height - s->height)

            i = s->total_height - s->height;

        y1 = s->y_base - i;

        if (y1 < 0)

            y1 += s->total_height;

        for(i = 0; i < ydelta; i++) {

            if (s->y_displayed == y1)

                break;

            if (--s->y_displayed < 0)

                s->y_displayed = s->total_height - 1;

        }

    }

    console_refresh(s);

}

static void console_put_lf(TextConsole *s)

{

    TextCell *c;

    int x, y1;

    s->y++;

    if (s->y >= s->height) {

        s->y = s->height - 1;

        if (s->y_displayed == s->y_base) {

            if (++s->y_displayed == s->total_height)

                s->y_displayed = 0;

        }

        if (++s->y_base == s->total_height)

            s->y_base = 0;

        if (s->backscroll_height < s->total_height)

            s->backscroll_height++;

        y1 = (s->y_base + s->height - 1) % s->total_height;

        c = &s->cells[y1 * s->width];

        for(x = 0; x < s->width; x++) {

            c->ch = ' ';

            c->t_attrib = s->t_attrib_default;

            c++;

        }

        if (s == active_console && s->y_displayed == s->y_base) {

            vga_bitblt(s->ds, 0, FONT_HEIGHT, 0, 0,

                       s->width * FONT_WIDTH,

                       (s->height - 1) * FONT_HEIGHT);

            vga_fill_rect(s->ds, 0, (s->height - 1) * FONT_HEIGHT,

                          s->width * FONT_WIDTH, FONT_HEIGHT,

                          color_table[0][s->t_attrib_default.bgcol]);

            dpy_update(s->ds, 0, 0,

                       s->width * FONT_WIDTH, s->height * FONT_HEIGHT);

        }

    }

}

/* Set console attributes depending on the current escape codes.

 * NOTE: I know this code is not very efficient (checking every color for it

 * self) but it is more readable and better maintainable.

 */

static void console_handle_escape(TextConsole *s)

{

    int i;

    for (i=0; i<s->nb_esc_params; i++) {

        switch (s->esc_params[i]) {

            case 0: /* reset all console attributes to default */

                s->t_attrib = s->t_attrib_default;

                break;

            case 1:

                s->t_attrib.bold = 1;

                break;

            case 4:

                s->t_attrib.uline = 1;

                break;

            case 5:

                s->t_attrib.blink = 1;

                break;

            case 7:

                s->t_attrib.invers = 1;

                break;

            case 8:

                s->t_attrib.unvisible = 1;

                break;

            case 22:

                s->t_attrib.bold = 0;

                break;

            case 24:

                s->t_attrib.uline = 0;

                break;

            case 25:

                s->t_attrib.blink = 0;

                break;

            case 27:

                s->t_attrib.invers = 0;

                break;

            case 28:

                s->t_attrib.unvisible = 0;

                break;

            /* set foreground color */

            case 30:

                s->t_attrib.fgcol=COLOR_BLACK;

                break;

            case 31:

                s->t_attrib.fgcol=COLOR_RED;

                break;

            case 32:

                s->t_attrib.fgcol=COLOR_GREEN;

                break;

            case 33:

                s->t_attrib.fgcol=COLOR_YELLOW;

                break;

            case 34:

                s->t_attrib.fgcol=COLOR_BLUE;

                break;

            case 35:

                s->t_attrib.fgcol=COLOR_MAGENTA;

                break;

            case 36:

                s->t_attrib.fgcol=COLOR_CYAN;

                break;

            case 37:

                s->t_attrib.fgcol=COLOR_WHITE;

                break;

            /* set background color */

            case 40:

                s->t_attrib.bgcol=COLOR_BLACK;

                break;

            case 41:

                s->t_attrib.bgcol=COLOR_RED;

                break;

            case 42:

                s->t_attrib.bgcol=COLOR_GREEN;

                break;

            case 43:

                s->t_attrib.bgcol=COLOR_YELLOW;

                break;

            case 44:

                s->t_attrib.bgcol=COLOR_BLUE;

                break;

            case 45:

                s->t_attrib.bgcol=COLOR_MAGENTA;

                break;

            case 46:

                s->t_attrib.bgcol=COLOR_CYAN;

                break;

            case 47:

                s->t_attrib.bgcol=COLOR_WHITE;

                break;

        }

    }

}

static void console_clear_xy(TextConsole *s, int x, int y)

{

    int y1 = (s->y_base + y) % s->total_height;

    TextCell *c = &s->cells[y1 * s->width + x];

    c->ch = ' ';

    c->t_attrib = s->t_attrib_default;

    c++;

    update_xy(s, x, y);

}

static void console_putchar(TextConsole *s, int ch)

{

    TextCell *c;

    int y1, i;

    int x, y;

    switch(s->state) {

    case TTY_STATE_NORM:

        switch(ch) {

        case '\r':  /* carriage return */

            s->x = 0;

            break;

        case '\n':  /* newline */

            console_put_lf(s);

            break;

        case '\b':  /* backspace */

            if (s->x > 0)

                s->x--;

            break;

        case '\t':  /* tabspace */

            if (s->x + (8 - (s->x % 8)) > s->width) {

                s->x = 0;

                console_put_lf(s);

            } else {

                s->x = s->x + (8 - (s->x % 8));

            }

            break;

        case '\a':  /* alert aka. bell */

            /* TODO: has to be implemented */

            break;

        case 14:

            /* SI (shift in), character set 0 (ignored) */

            break;

        case 15:

            /* SO (shift out), character set 1 (ignored) */

            break;

        case 27:    /* esc (introducing an escape sequence) */

            s->state = TTY_STATE_ESC;

            break;

        default:

            if (s->x >= s->width) {

                /* line wrap */

                s->x = 0;

                console_put_lf(s);

            }

            y1 = (s->y_base + s->y) % s->total_height;

            c = &s->cells[y1 * s->width + s->x];

            c->ch = ch;

            c->t_attrib = s->t_attrib;

            update_xy(s, s->x, s->y);

            s->x++;

            break;

        }

        break;

    case TTY_STATE_ESC: /* check if it is a terminal escape sequence */

        if (ch == '[') {

            for(i=0;i<MAX_ESC_PARAMS;i++)

                s->esc_params[i] = 0;

            s->nb_esc_params = 0;

            s->state = TTY_STATE_CSI;

        } else {

            s->state = TTY_STATE_NORM;

        }

        break;

    case TTY_STATE_CSI: /* handle escape sequence parameters */

        if (ch >= '0' && ch <= '9') {

            if (s->nb_esc_params < MAX_ESC_PARAMS) {

                s->esc_params[s->nb_esc_params] =

                    s->esc_params[s->nb_esc_params] * 10 + ch - '0';

            }

        } else {

            s->nb_esc_params++;

            if (ch == ';')

                break;

#ifdef DEBUG_CONSOLE

            fprintf(stderr, "escape sequence CSI%d;%d%c, %d parameters\n",

                    s->esc_params[0], s->esc_params[1], ch, s->nb_esc_params);

#endif

            s->state = TTY_STATE_NORM;

            switch(ch) {

            case 'A':

                /* move cursor up */

                if (s->esc_params[0] == 0) {

                    s->esc_params[0] = 1;

                }

                s->y -= s->esc_params[0];

                if (s->y < 0) {

                    s->y = 0;

                }

                break;

            case 'B':

                /* move cursor down */

                if (s->esc_params[0] == 0) {

                    s->esc_params[0] = 1;

                }

                s->y += s->esc_params[0];

                if (s->y >= s->height) {

                    s->y = s->height - 1;

                }

                break;

            case 'C':

                /* move cursor right */

                if (s->esc_params[0] == 0) {

                    s->esc_params[0] = 1;

                }

                s->x += s->esc_params[0];

                if (s->x >= s->width) {

                    s->x = s->width - 1;

                }

                break;

            case 'D':

                /* move cursor left */

                if (s->esc_params[0] == 0) {

                    s->esc_params[0] = 1;

                }