---

video.c

Go to the documentation of this file.

/*!     \file drivers/video/video.c
 *      \brief Low level video controller 6845 driver.
 *      \author Andrea Righi <drizzt@inwind.it>
 *      \date Last update: 2003-11-08
 *      \note Copyright (&copy;) 2003 Andrea Righi
 */

#include <const.h>
#include <stdarg.h>

#include <arch/i386.h>
#include <arch/mem.h>
#include <arch/paging.h>

#include <kernel/console.h>
#include <kernel/semaphore.h>
#include <kernel/speaker.h>
#include <kernel/task.h>

#include <kernel/video.h>

/** \ingroup Drivers
 *  \defgroup VideoDriver Video Controller 6845
 *  The low level video controller 6845 driver.
 *  @{
 */

//! Video base address port.
word    crt_port;
//! Video width (columns).
byte    crt_width;
//! Video height (rows).
byte    crt_height;

//! \brief Refresh cursor position for a selected console.
//! \param console The selected console address.
//! \return
//!     \li #TRUE if the current console is the foreground console;
//!     \li #FALSE otherwise.
//! \note
//!     There is no reason to refresh the cursor if the selected
//!     console is not the foreground console. In this case the
//!     function returns a value of #FALSE.
bool move_cur(console_t *console)
{
        dword IF = GET_IF();

        disable();

        // Move the cursor only in the current console                  //
        if ( (console == get_console_addr(0)) )
        {
                // Refresh video cursor position with cur_pos value.    //
                // Registers 14-15 tell the 6845 where to put the       //
                // cursor.                                              //
                outportb(crt_port + 0, 14);
                outportb(crt_port + 1, (console->cur_pos) >> 8);
                outportb(crt_port + 0, 15);
                outportb(crt_port + 1, (console->cur_pos));
                SET_IF(IF);
                return(TRUE);
        }
        SET_IF(IF);
        return(FALSE);
}


//! \brief Clear the screen of the selected console.
//! \param console The selected console address.
void k_clrscr(console_t *console)
{
        dword IF = GET_IF();

        disable();

        memsetw((void *)(console->vid_buffer), BLANK, crt_width*crt_height);
        console->cur_pos=0;

        SET_IF(IF);

        move_cur(console);
}

//! \brief Get the cursor position of the selected console.
//! \param console The selected console address.
//! \return
//!     The cursor position (in characters from the beginning
//!     of the video buffer).
word k_get_cur_pos(console_t *console)
{
        return(console->cur_pos);
}

//! \brief Set the cursor position of the selected console.
//! \param console The selected console address.
//! \param pos
//!     The cursor position (in characters from the beginning
//!     of the video buffer).
//! \return
//!     \li #TRUE on success;
//!     \li #FALSE if the position is over the buffer.
bool k_set_cur_pos(console_t *console, word pos)
{
        if ( pos < (crt_width*crt_height) )
        {
                console->cur_pos = pos;
                move_cur(console);
                return(TRUE);
        }
        return(FALSE);
}

//! \brief Get the current color of the selected console.
//! \param console The selected console address.
//! \return The current color code (see console.h).
byte k_get_color(console_t *console)
{
        return(console->cur_color);
}

//! \brief Set the current color of the selected console.
//! \param console The selected console address.
//! \param attrib The current color code (see console.h).
void k_set_color(console_t *console, byte attrib)
{
        console->cur_color = attrib;
}

//! \brief Scroll up the screen of the selected console.
//! \param console The selected console address.
void k_scroll_up(console_t *console)
{
        dword IF = GET_IF();

        disable();

        // Scroll up                                                    //
        memcpy( (void *)(console->vid_buffer),
                ((void *)(console->vid_buffer))+crt_width*2,
                crt_width*(crt_height-1)*2 );

        // Blank the bottom line of the screen                          //
        memsetw((void *)( ((void *)(console->vid_buffer)) + crt_width*(crt_height-1)*2),
                 BLANK, crt_width);

        (console->cur_pos)-=crt_width;

        SET_IF(IF);

        move_cur(console);
}

//! \brief
//!     Set the (x, y) coordinates as the current position in the
//!     selected console.
//! \param console The selected console address.
//! \param x The column position.
//! \param y The row position.
void k_gotoxy(console_t *console, int x, int y)
{
        dword IF = GET_IF();

        // Round x, y to CRT bounds                                     //
        if (x != -1)
                x = x % crt_width;
        else
                x = console->cur_pos % crt_width;

        if (y != -1)
                y = y % crt_height;
        else
                y = console->cur_pos / crt_width;

        disable();
        console->cur_pos = y*crt_width + x;

        SET_IF(IF);

        move_cur(console);
}

//! \brief Put a character in the selected console.
//! \param console The selected console address.
//! \param c The ASCII code of the character to print.
void _kputchar(console_t *console, byte c)
{
        switch (c)
        {
                case '\n':
                        (console->cur_pos)+=crt_width;
                        (console->cur_pos)-=(console->cur_pos)%crt_width;
                        break;
                case '\r':
                        (console->cur_pos)-=(console->cur_pos)%crt_width;
                        break;
                case '\b':
                        if ((console->cur_pos) > 0)
                        {
                                (console->vid_buffer)[--(console->cur_pos)] =
                                        ((console->cur_color) <<8 ) | ' ';
                        }
                        break;
                case '\t':
                        (console->cur_pos)+=8;
                        break;
                case '\a': // CTRL+G => system beep! //
                        beep();
                        return;
                        break;

                default:
                {
                        (console->vid_buffer)[console->cur_pos] = ((console->cur_color) << 8) | c;
                        (console->cur_pos)++;
                }
        }

        // Check if cursor is at the bottom of the screen               //
        if ( console->cur_pos >= (crt_width * crt_height) )
                k_scroll_up(console);

        move_cur(console);
}

//! \brief Get the CRT height (in characters).
//! \return The CRT heitht.
byte k_get_crt_height()
{
        return( crt_height );
}

//! \brief Get the CRT width (in characters).
//! \return The CRT width.
byte k_get_crt_width()
{
        return( crt_width );
}

//! \brief Initialize the video parameters.
void init_video()
{
        crt_port=0x3D4;
        crt_width=80;
        crt_height=25;
}

/** @} */ // end of VideoDriver

---