source: mainline/uspace/srv/hid/console/console.c@ dd495c9

/*
 * Copyright (c) 2024 Jiri Svoboda
 * Copyright (c) 2011 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup console
 * @{
 */
/** @file
 */

#include <async.h>
#include <stdio.h>
#include <adt/prodcons.h>
#include <io/console.h>
#include <io/input.h>
#include <ipc/vfs.h>
#include <errno.h>
#include <str_error.h>
#include <loc.h>
#include <io/con_srv.h>
#include <io/kbd_event.h>
#include <io/keycode.h>
#include <io/chargrid.h>
#include <io/output.h>
#include <align.h>
#include <as.h>
#include <task.h>
#include <fibril_synch.h>
#include <stdatomic.h>
#include <stdlib.h>
#include <str.h>
#include "console.h"

#define NAME       "console"
#define NAMESPACE  "term"

#define UTF8_CHAR_BUFFER_SIZE  (STR_BOUNDS(1) + 1)

typedef struct {
        atomic_flag refcnt;      /**< Connection reference count */
        prodcons_t input_pc;  /**< Incoming console events */

        /**
         * Not yet sent bytes of last char event.
         */
        char char_remains[UTF8_CHAR_BUFFER_SIZE];
        size_t char_remains_len;  /**< Number of not yet sent bytes. */

        fibril_mutex_t mtx;  /**< Lock protecting mutable fields */

        size_t index;           /**< Console index */
        service_id_t dsid;      /**< Service handle */

        sysarg_t cols;         /**< Number of columns */
        sysarg_t rows;         /**< Number of rows */
        console_caps_t ccaps;  /**< Console capabilities */

        sysarg_t ucols;         /**< Number of columns in user buffer */
        sysarg_t urows;         /**< Number of rows in user buffer */
        charfield_t *ubuf;      /**< User buffer */

        chargrid_t *frontbuf;    /**< Front buffer */
        frontbuf_handle_t fbid;  /**< Front buffer handle */
        con_srvs_t srvs;         /**< Console service setup */
} console_t;

static loc_srv_t *console_srv;

/** Input server proxy */
static input_t *input;
static bool active = false;

/** Session to the output server */
static async_sess_t *output_sess;

/** Output dimensions */
static sysarg_t cols;
static sysarg_t rows;

/** Mouse pointer X coordinate */
static int pointer_x;
/** Mouse pointer Y coordinate */
static int pointer_y;
/** Character under mouse cursor */
static charfield_t pointer_bg;

static int mouse_scale_x = 4;
static int mouse_scale_y = 8;

/** Array of data for virtual consoles */
static console_t consoles[CONSOLE_COUNT];

/** Mutex for console switching */
static FIBRIL_MUTEX_INITIALIZE(switch_mtx);

static console_t *active_console = &consoles[0];

static errno_t input_ev_active(input_t *);
static errno_t input_ev_deactive(input_t *);
static errno_t input_ev_key(input_t *, unsigned, kbd_event_type_t, keycode_t,
    keymod_t, char32_t);
static errno_t input_ev_move(input_t *, unsigned, int, int);
static errno_t input_ev_abs_move(input_t *, unsigned, unsigned, unsigned,
    unsigned, unsigned);
static errno_t input_ev_button(input_t *, unsigned, int, int);
static errno_t input_ev_dclick(input_t *, unsigned, int);

static input_ev_ops_t input_ev_ops = {
        .active = input_ev_active,
        .deactive = input_ev_deactive,
        .key = input_ev_key,
        .move = input_ev_move,
        .abs_move = input_ev_abs_move,
        .button = input_ev_button,
        .dclick = input_ev_dclick
};

static errno_t cons_open(con_srvs_t *, con_srv_t *);
static errno_t cons_close(con_srv_t *);
static errno_t cons_read(con_srv_t *, void *, size_t, size_t *);
static errno_t cons_write(con_srv_t *, void *, size_t, size_t *);
static void cons_sync(con_srv_t *);
static void cons_clear(con_srv_t *);
static void cons_set_pos(con_srv_t *, sysarg_t col, sysarg_t row);
static errno_t cons_get_pos(con_srv_t *, sysarg_t *, sysarg_t *);
static errno_t cons_get_size(con_srv_t *, sysarg_t *, sysarg_t *);
static errno_t cons_get_color_cap(con_srv_t *, console_caps_t *);
static void cons_set_style(con_srv_t *, console_style_t);
static void cons_set_color(con_srv_t *, console_color_t, console_color_t,
    console_color_attr_t);
static void cons_set_rgb_color(con_srv_t *, pixel_t, pixel_t);
static void cons_set_cursor_visibility(con_srv_t *, bool);
static errno_t cons_set_caption(con_srv_t *, const char *);
static errno_t cons_get_event(con_srv_t *, cons_event_t *);
static errno_t cons_map(con_srv_t *, sysarg_t, sysarg_t, charfield_t **);
static void cons_unmap(con_srv_t *);
static void cons_buf_update(con_srv_t *, sysarg_t, sysarg_t, sysarg_t,
    sysarg_t);

static con_ops_t con_ops = {
        .open = cons_open,
        .close = cons_close,
        .read = cons_read,
        .write = cons_write,
        .sync = cons_sync,
        .clear = cons_clear,
        .set_pos = cons_set_pos,
        .get_pos = cons_get_pos,
        .get_size = cons_get_size,
        .get_color_cap = cons_get_color_cap,
        .set_style = cons_set_style,
        .set_color = cons_set_color,
        .set_rgb_color = cons_set_rgb_color,
        .set_cursor_visibility = cons_set_cursor_visibility,
        .set_caption = cons_set_caption,
        .get_event = cons_get_event,
        .map = cons_map,
        .unmap = cons_unmap,
        .update = cons_buf_update
};

static void pointer_draw(void);
static void pointer_undraw(void);

static console_t *srv_to_console(con_srv_t *srv)
{
        return srv->srvs->sarg;
}

static void cons_update(console_t *cons)
{
        fibril_mutex_lock(&switch_mtx);
        fibril_mutex_lock(&cons->mtx);

        if ((active) && (cons == active_console)) {
                output_update(output_sess, cons->fbid);
                output_cursor_update(output_sess, cons->fbid);
        }

        fibril_mutex_unlock(&cons->mtx);
        fibril_mutex_unlock(&switch_mtx);
}

static void cons_update_cursor(console_t *cons)
{
        fibril_mutex_lock(&switch_mtx);
        fibril_mutex_lock(&cons->mtx);

        if ((active) && (cons == active_console))
                output_cursor_update(output_sess, cons->fbid);

        fibril_mutex_unlock(&cons->mtx);
        fibril_mutex_unlock(&switch_mtx);
}

static void cons_damage(console_t *cons)
{
        fibril_mutex_lock(&switch_mtx);
        fibril_mutex_lock(&cons->mtx);

        if ((active) && (cons == active_console)) {
                output_damage(output_sess, cons->fbid, 0, 0, cons->cols,
                    cons->rows);
                output_cursor_update(output_sess, cons->fbid);
        }

        fibril_mutex_unlock(&cons->mtx);
        fibril_mutex_unlock(&switch_mtx);
}

static void cons_switch(unsigned int index)
{
        /*
         * The first undefined index is reserved
         * for switching to the kernel console.
         */
        if (index == CONSOLE_COUNT) {
                if (console_kcon())
                        active = false;

                return;
        }

        if (index > CONSOLE_COUNT)
                return;

        console_t *cons = &consoles[index];

        fibril_mutex_lock(&switch_mtx);
        pointer_undraw();

        if (cons == active_console) {
                fibril_mutex_unlock(&switch_mtx);
                return;
        }

        active_console = cons;

        pointer_draw();
        fibril_mutex_unlock(&switch_mtx);

        cons_damage(cons);
}

/** Draw mouse pointer. */
static void pointer_draw(void)
{
        charfield_t *ch;
        int col, row;

        /* Downscale coordinates to text resolution */
        col = pointer_x / mouse_scale_x;
        row = pointer_y / mouse_scale_y;

        /* Make sure they are in range */
        if (col < 0 || row < 0 || col >= (int)cols || row >= (int)rows)
                return;

        ch = chargrid_charfield_at(active_console->frontbuf, col, row);

        /*
         * Store background attributes for undrawing the pointer.
         * This is necessary as styles cannot be inverted with
         * round trip (unlike RGB or INDEX)
         */
        pointer_bg = *ch;

        /* In general the color should be a one's complement of the background */
        if (ch->attrs.type == CHAR_ATTR_INDEX) {
                ch->attrs.val.index.bgcolor ^= 0xf;
                ch->attrs.val.index.fgcolor ^= 0xf;
        } else if (ch->attrs.type == CHAR_ATTR_RGB) {
                ch->attrs.val.rgb.fgcolor ^= 0xffffff;
                ch->attrs.val.rgb.bgcolor ^= 0xffffff;
        } else if (ch->attrs.type == CHAR_ATTR_STYLE) {
                /* Don't have a proper inverse for each style */
                if (ch->attrs.val.style == STYLE_INVERTED)
                        ch->attrs.val.style = STYLE_NORMAL;
                else
                        ch->attrs.val.style = STYLE_INVERTED;
        }

        /* Make sure the cell gets updated */
        ch->flags |= CHAR_FLAG_DIRTY;
}

/** Undraw mouse pointer. */
static void pointer_undraw(void)
{
        charfield_t *ch;
        int col, row;

        col = pointer_x / mouse_scale_x;
        row = pointer_y / mouse_scale_y;
        if (col < 0 || row < 0 || col >= (int)cols || row >= (int)rows)
                return;

        ch = chargrid_charfield_at(active_console->frontbuf, col, row);
        *ch = pointer_bg;
        ch->flags |= CHAR_FLAG_DIRTY;
}

/** Queue console event.
 *
 * @param cons Console
 * @param ev Console event
 */
static void console_queue_cons_event(console_t *cons, cons_event_t *ev)
{
        /* Got key press/release event */
        cons_event_t *event =
            (cons_event_t *) malloc(sizeof(cons_event_t));
        if (event == NULL)
                return;

        *event = *ev;
        link_initialize(&event->link);

        prodcons_produce(&cons->input_pc, &event->link);
}

static errno_t input_ev_active(input_t *input)
{
        active = true;
        output_claim(output_sess);
        cons_damage(active_console);

        return EOK;
}

static errno_t input_ev_deactive(input_t *input)
{
        active = false;
        output_yield(output_sess);

        return EOK;
}

static errno_t input_ev_key(input_t *input, unsigned kbd_id,
    kbd_event_type_t type, keycode_t key, keymod_t mods, char32_t c)
{
        cons_event_t event;
        bool alt;
        bool shift;

        alt = (mods & KM_ALT) != 0 && (mods & (KM_CTRL | KM_SHIFT)) == 0;
        shift = (mods & KM_SHIFT) != 0 && (mods & (KM_CTRL | KM_ALT)) == 0;

        /* Switch console on Alt+Fn or Shift+Fn */
        if ((key >= KC_F1) && (key <= KC_F1 + CONSOLE_COUNT) &&
            (alt || shift)) {
                cons_switch(key - KC_F1);
        } else {
                /* Got key press/release event */
                event.type = CEV_KEY;

                (void)kbd_id;
                event.ev.key.type = type;
                event.ev.key.key = key;
                event.ev.key.mods = mods;
                event.ev.key.c = c;

                console_queue_cons_event(active_console, &event);
        }

        return EOK;
}

/** Update pointer position.
 *
 * @param new_x New X coordinate (in pixels)
 * @param new_y New Y coordinate (in pixels)
 */
static void pointer_update(int new_x, int new_y)
{
        bool upd_pointer;

        /* Make sure coordinates are in range */

        if (new_x < 0)
                new_x = 0;
        if (new_x >= (int)cols * mouse_scale_x)
                new_x = cols * mouse_scale_x - 1;
        if (new_y < 0)
                new_y = 0;
        if (new_y >= (int)rows * mouse_scale_y)
                new_y = rows * mouse_scale_y - 1;

        /* Determine if pointer moved to a different character cell */
        upd_pointer = (new_x / mouse_scale_x != pointer_x / mouse_scale_x) ||
            (new_y / mouse_scale_y != pointer_y / mouse_scale_y);

        if (upd_pointer)
                pointer_undraw();

        /* Store new pointer position */
        pointer_x = new_x;
        pointer_y = new_y;

        if (upd_pointer) {
                pointer_draw();
                cons_update(active_console);
        }
}

static errno_t input_ev_move(input_t *input, unsigned pos_id, int dx, int dy)
{
        (void) pos_id;
        pointer_update(pointer_x + dx, pointer_y + dy);
        return EOK;
}

static errno_t input_ev_abs_move(input_t *input, unsigned pos_id, unsigned x,
    unsigned y, unsigned max_x, unsigned max_y)
{
        (void)pos_id;
        pointer_update(mouse_scale_x * cols * x / max_x, mouse_scale_y * rows * y / max_y);
        return EOK;
}

static errno_t input_ev_button(input_t *input, unsigned pos_id, int bnum,
    int bpress)
{
        cons_event_t event;

        (void)pos_id;

        event.type = CEV_POS;
        event.ev.pos.type = bpress ? POS_PRESS : POS_RELEASE;
        event.ev.pos.btn_num = bnum;
        event.ev.pos.hpos = pointer_x / mouse_scale_x;
        event.ev.pos.vpos = pointer_y / mouse_scale_y;

        console_queue_cons_event(active_console, &event);
        return EOK;
}

static errno_t input_ev_dclick(input_t *input, unsigned pos_id, int bnum)
{
        cons_event_t event;

        (void)pos_id;

        event.type = CEV_POS;
        event.ev.pos.type = POS_DCLICK;
        event.ev.pos.btn_num = bnum;
        event.ev.pos.hpos = pointer_x / mouse_scale_x;
        event.ev.pos.vpos = pointer_y / mouse_scale_y;

        console_queue_cons_event(active_console, &event);
        return EOK;
}

/** Process a character from the client (TTY emulation). */
static void cons_write_char(console_t *cons, char32_t ch)
{
        sysarg_t updated = 0;

        fibril_mutex_lock(&cons->mtx);
        pointer_undraw();

        switch (ch) {
        case '\n':
                updated = chargrid_newline(cons->frontbuf);
                break;
        case '\r':
                break;
        case '\t':
                updated = chargrid_tabstop(cons->frontbuf, 8);
                break;
        case '\b':
                updated = chargrid_backspace(cons->frontbuf);
                break;
        default:
                updated = chargrid_putuchar(cons->frontbuf, ch, true);
        }

        pointer_draw();
        fibril_mutex_unlock(&cons->mtx);

        if (updated > 1)
                cons_update(cons);
}

static void cons_set_cursor_vis(console_t *cons, bool visible)
{
        fibril_mutex_lock(&cons->mtx);
        pointer_undraw();
        chargrid_set_cursor_visibility(cons->frontbuf, visible);
        pointer_draw();
        fibril_mutex_unlock(&cons->mtx);

        cons_update_cursor(cons);
}

static errno_t cons_open(con_srvs_t *srvs, con_srv_t *srv)
{
        return EOK;
}

static errno_t cons_close(con_srv_t *srv)
{
        return EOK;
}

static errno_t cons_read(con_srv_t *srv, void *buf, size_t size, size_t *nread)
{
        uint8_t *bbuf = buf;
        console_t *cons = srv_to_console(srv);
        size_t pos = 0;

        /*
         * Read input from keyboard and copy it to the buffer.
         * We need to handle situation when wchar is split by 2 following
         * reads.
         */
        while (pos < size) {
                /* Copy to the buffer remaining characters. */
                while ((pos < size) && (cons->char_remains_len > 0)) {
                        bbuf[pos] = cons->char_remains[0];
                        pos++;

                        /* Unshift the array. */
                        for (size_t i = 1; i < cons->char_remains_len; i++)
                                cons->char_remains[i - 1] = cons->char_remains[i];

                        cons->char_remains_len--;
                }

                /* Still not enough? Then get another key from the queue. */
                if (pos < size) {
                        link_t *link = prodcons_consume(&cons->input_pc);
                        cons_event_t *event = list_get_instance(link,
                            cons_event_t, link);

                        /* Accept key presses of printable chars only. */
                        if (event->type == CEV_KEY && event->ev.key.type == KEY_PRESS &&
                            (event->ev.key.c != 0)) {
                                char32_t tmp[2] = { event->ev.key.c, 0 };
                                wstr_to_str(cons->char_remains, UTF8_CHAR_BUFFER_SIZE, tmp);
                                cons->char_remains_len = str_size(cons->char_remains);
                        }

                        free(event);
                }
        }

        *nread = size;
        return EOK;
}

static errno_t cons_write(con_srv_t *srv, void *data, size_t size, size_t *nwritten)
{
        console_t *cons = srv_to_console(srv);

        size_t off = 0;
        while (off < size)
                cons_write_char(cons, str_decode(data, &off, size));

        *nwritten = size;
        return EOK;
}

static void cons_sync(con_srv_t *srv)
{
        console_t *cons = srv_to_console(srv);

        cons_update(cons);
}

static void cons_clear(con_srv_t *srv)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        pointer_undraw();
        chargrid_clear(cons->frontbuf);
        pointer_draw();
        fibril_mutex_unlock(&cons->mtx);

        cons_update(cons);
}

static void cons_set_pos(con_srv_t *srv, sysarg_t col, sysarg_t row)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        pointer_undraw();
        chargrid_set_cursor(cons->frontbuf, col, row);
        pointer_draw();
        fibril_mutex_unlock(&cons->mtx);

        cons_update_cursor(cons);
}

static errno_t cons_get_pos(con_srv_t *srv, sysarg_t *col, sysarg_t *row)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        chargrid_get_cursor(cons->frontbuf, col, row);
        fibril_mutex_unlock(&cons->mtx);

        return EOK;
}

static errno_t cons_get_size(con_srv_t *srv, sysarg_t *cols, sysarg_t *rows)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        *cols = cons->cols;
        *rows = cons->rows;
        fibril_mutex_unlock(&cons->mtx);

        return EOK;
}

static errno_t cons_get_color_cap(con_srv_t *srv, console_caps_t *ccaps)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        *ccaps = cons->ccaps;
        fibril_mutex_unlock(&cons->mtx);

        return EOK;
}

static void cons_set_style(con_srv_t *srv, console_style_t style)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        chargrid_set_style(cons->frontbuf, style);
        fibril_mutex_unlock(&cons->mtx);
}

static void cons_set_color(con_srv_t *srv, console_color_t bgcolor,
    console_color_t fgcolor, console_color_attr_t attr)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        chargrid_set_color(cons->frontbuf, bgcolor, fgcolor, attr);
        fibril_mutex_unlock(&cons->mtx);
}

static void cons_set_rgb_color(con_srv_t *srv, pixel_t bgcolor,
    pixel_t fgcolor)
{
        console_t *cons = srv_to_console(srv);

        fibril_mutex_lock(&cons->mtx);
        chargrid_set_rgb_color(cons->frontbuf, bgcolor, fgcolor);
        fibril_mutex_unlock(&cons->mtx);
}

static void cons_set_cursor_visibility(con_srv_t *srv, bool visible)
{
        console_t *cons = srv_to_console(srv);

        cons_set_cursor_vis(cons, visible);
}

static errno_t cons_set_caption(con_srv_t *srv, const char *caption)
{
        console_t *cons = srv_to_console(srv);

        (void) cons;
        (void) caption;
        return EOK;
}

static errno_t cons_get_event(con_srv_t *srv, cons_event_t *event)
{
        console_t *cons = srv_to_console(srv);
        link_t *link = prodcons_consume(&cons->input_pc);
        cons_event_t *cevent = list_get_instance(link, cons_event_t, link);

        *event = *cevent;
        free(cevent);
        return EOK;
}

/** Create shared buffer for efficient rendering.
 *
 * @param srv Console server
 * @param cols Number of columns in buffer
 * @param rows Number of rows in buffer
 * @param rbuf Place to store pointer to new sharable buffer
 *
 * @return EOK on sucess or an error code
 */
static errno_t cons_map(con_srv_t *srv, sysarg_t cols, sysarg_t rows,
    charfield_t **rbuf)
{
        console_t *cons = srv_to_console(srv);
        void *buf;

        fibril_mutex_lock(&cons->mtx);

        if (cons->ubuf != NULL) {
                fibril_mutex_unlock(&cons->mtx);
                return EBUSY;
        }

        buf = as_area_create(AS_AREA_ANY, cols * rows * sizeof(charfield_t),
            AS_AREA_READ | AS_AREA_WRITE | AS_AREA_CACHEABLE, AS_AREA_UNPAGED);
        if (buf == AS_MAP_FAILED) {
                fibril_mutex_unlock(&cons->mtx);
                return ENOMEM;
        }

        cons->ucols = cols;
        cons->urows = rows;
        cons->ubuf = buf;
        fibril_mutex_unlock(&cons->mtx);

        *rbuf = buf;
        return EOK;
}

/** Delete shared buffer.
 *
 * @param srv Console server
 */
static void cons_unmap(con_srv_t *srv)
{
        console_t *cons = srv_to_console(srv);
        void *buf;

        fibril_mutex_lock(&cons->mtx);

        buf = cons->ubuf;
        cons->ubuf = NULL;

        if (buf != NULL)
                as_area_destroy(buf);

        fibril_mutex_unlock(&cons->mtx);
}

/** Update area of console from shared buffer.
 *
 * @param srv Console server
 * @param c0 Column coordinate of top-left corner (inclusive)
 * @param r0 Row coordinate of top-left corner (inclusive)
 * @param c1 Column coordinate of bottom-right corner (exclusive)
 * @param r1 Row coordinate of bottom-right corner (exclusive)
 */
static void cons_buf_update(con_srv_t *srv, sysarg_t c0, sysarg_t r0,
    sysarg_t c1, sysarg_t r1)
{
        console_t *cons = srv_to_console(srv);
        charfield_t *ch;
        sysarg_t col, row;

        fibril_mutex_lock(&cons->mtx);

        if (cons->ubuf == NULL) {
                fibril_mutex_unlock(&cons->mtx);
                return;
        }

        /* Make sure we have meaningful coordinates, within bounds */

        if (c1 > cons->ucols)
                c1 = cons->ucols;
        if (c1 > cons->cols)
                c1 = cons->cols;
        if (c0 >= c1) {
                fibril_mutex_unlock(&cons->mtx);
                return;
        }
        if (r1 > cons->urows)
                r1 = cons->urows;
        if (r1 > cons->rows)
                r1 = cons->rows;
        if (r0 >= r1) {
                fibril_mutex_unlock(&cons->mtx);
                return;
        }

        /* Update front buffer from user buffer */

        pointer_undraw();

        for (row = r0; row < r1; row++) {
                for (col = c0; col < c1; col++) {
                        ch = chargrid_charfield_at(cons->frontbuf, col, row);
                        *ch = cons->ubuf[row * cons->ucols + col];
                }
        }

        pointer_draw();
        fibril_mutex_unlock(&cons->mtx);

        /* Update console */
        cons_update(cons);
}

static void client_connection(ipc_call_t *icall, void *arg)
{
        console_t *cons = NULL;

        for (size_t i = 0; i < CONSOLE_COUNT; i++) {
                if (consoles[i].dsid == (service_id_t) ipc_get_arg2(icall)) {
                        cons = &consoles[i];
                        break;
                }
        }

        if (cons == NULL) {
                async_answer_0(icall, ENOENT);
                return;
        }

        if (!atomic_flag_test_and_set(&cons->refcnt))
                cons_set_cursor_vis(cons, true);

        con_conn(icall, &cons->srvs);
}

static errno_t input_connect(const char *svc)
{
        async_sess_t *sess;
        service_id_t dsid;

        errno_t rc = loc_service_get_id(svc, &dsid, 0);
        if (rc != EOK) {
                printf("%s: Input service %s not found\n", NAME, svc);
                return rc;
        }

        sess = loc_service_connect(dsid, INTERFACE_INPUT, 0);
        if (sess == NULL) {
                printf("%s: Unable to connect to input service %s\n", NAME,
                    svc);
                return EIO;
        }

        rc = input_open(sess, &input_ev_ops, NULL, &input);
        if (rc != EOK) {
                async_hangup(sess);
                printf("%s: Unable to communicate with service %s (%s)\n",
                    NAME, svc, str_error(rc));
                return rc;
        }

        return EOK;
}

static async_sess_t *output_connect(const char *svc)
{
        async_sess_t *sess;
        service_id_t dsid;

        errno_t rc = loc_service_get_id(svc, &dsid, 0);
        if (rc == EOK) {
                sess = loc_service_connect(dsid, INTERFACE_OUTPUT, 0);
                if (sess == NULL) {
                        printf("%s: Unable to connect to output service %s\n",
                            NAME, svc);
                        return NULL;
                }
        } else
                return NULL;

        return sess;
}

static bool console_srv_init(char *input_svc, char *output_svc)
{
        /* Connect to input service */
        errno_t rc = input_connect(input_svc);
        if (rc != EOK)
                return false;

        /* Connect to output service */
        output_sess = output_connect(output_svc);
        if (output_sess == NULL)
                return false;

        /* Register server */
        async_set_fallback_port_handler(client_connection, NULL);
        rc = loc_server_register(NAME, &console_srv);
        if (rc != EOK) {
                printf("%s: Unable to register server (%s)\n", NAME,
                    str_error(rc));
                return false;
        }

        output_get_dimensions(output_sess, &cols, &rows);
        output_set_style(output_sess, STYLE_NORMAL);

        console_caps_t ccaps;
        output_get_caps(output_sess, &ccaps);

        /*
         * Inititalize consoles only if there are
         * actually some output devices.
         */
        if (ccaps != 0) {
                for (size_t i = 0; i < CONSOLE_COUNT; i++) {
                        consoles[i].index = i;
                        atomic_flag_clear(&consoles[i].refcnt);
                        fibril_mutex_initialize(&consoles[i].mtx);
                        prodcons_initialize(&consoles[i].input_pc);
                        consoles[i].char_remains_len = 0;

                        consoles[i].cols = cols;
                        consoles[i].rows = rows;
                        consoles[i].ccaps = ccaps;
                        consoles[i].frontbuf =
                            chargrid_create(cols, rows, CHARGRID_FLAG_SHARED);

                        if (consoles[i].frontbuf == NULL) {
                                printf("%s: Unable to allocate frontbuffer %zu\n", NAME, i);
                                return false;
                        }

                        consoles[i].fbid = output_frontbuf_create(output_sess,
                            consoles[i].frontbuf);
                        if (consoles[i].fbid == 0) {
                                printf("%s: Unable to create frontbuffer %zu\n", NAME, i);
                                return false;
                        }

                        con_srvs_init(&consoles[i].srvs);
                        consoles[i].srvs.ops = &con_ops;
                        consoles[i].srvs.sarg = &consoles[i];

                        char vc[LOC_NAME_MAXLEN + 1];
                        snprintf(vc, LOC_NAME_MAXLEN, "%s/vc%zu", NAMESPACE, i);

                        if (loc_service_register(console_srv, vc,
                            &consoles[i].dsid) != EOK) {
                                printf("%s: Unable to register device %s\n", NAME, vc);
                                return false;
                        }
                }

                input_activate(input);
                active = true;
                cons_damage(active_console);
        }

        return true;
}

static void usage(char *name)
{
        printf("Usage: %s <input_dev> <output_dev>\n", name);
}

int main(int argc, char *argv[])
{
        if (argc < 3) {
                usage(argv[0]);
                return -1;
        }

        printf("%s: HelenOS Console service\n", NAME);

        if (!console_srv_init(argv[1], argv[2]))
                return -1;

        printf("%s: Accepting connections\n", NAME);
        task_retval(0);
        async_manager();

        /* Never reached */
        return 0;
}

/** @}
 */