fbcon.c

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/*
 * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );

/** @file
 *
 * Frame buffer console
 *
 */

#include <string.h>
#include <errno.h>
#include <assert.h>
#include <byteswap.h>
#include <ipxe/ansiesc.h>
#include <ipxe/image.h>
#include <ipxe/pixbuf.h>
#include <ipxe/uaccess.h>
#include <ipxe/umalloc.h>
#include <ipxe/console.h>
#include <ipxe/fbcon.h>

/**
 * Calculate raw colour value
 *
 * @v fbcon             Frame buffer console
 * @v rgb               24-bit RGB value
 * @ret raw             Raw colour
 */
static uint32_t fbcon_colour ( struct fbcon *fbcon, uint32_t rgb ) {
        struct fbcon_colour_map *map = fbcon->map;
        uint8_t red = ( rgb >> 16 );
        uint8_t green = ( rgb >> 8 );
        uint8_t blue = ( rgb >> 0 );
        uint32_t mapped;

        mapped = ( ( ( red >> map->red_scale ) << map->red_lsb ) |
                   ( ( green >> map->green_scale ) << map->green_lsb ) |
                   ( ( blue >> map->blue_scale ) << map->blue_lsb ) );
        return cpu_to_le32 ( mapped );
}

/**
 * Calculate ANSI font colour
 *
 * @v fbcon             Frame buffer console
 * @v ansicol           ANSI colour value (0-based)
 * @ret colour          Raw colour
 */
static uint32_t fbcon_ansi_colour ( struct fbcon *fbcon,
                                    unsigned int ansicol ) {
        uint32_t rgb;

        /* Treat ansicol as 3-bit BGR with intensity 0xaa */
        rgb = ( ( ( ansicol & ( 1 << 0 ) ) ? 0xaa0000 : 0 ) |
                ( ( ansicol & ( 1 << 1 ) ) ? 0x00aa00 : 0 ) |
                ( ( ansicol & ( 1 << 2 ) ) ? 0x0000aa : 0 ) );

        return fbcon_colour ( fbcon, rgb );
}

/**
 * Set default foreground colour
 *
 * @v fbcon             Frame buffer console
 */
static void fbcon_set_default_foreground ( struct fbcon *fbcon ) {

        /* Default to non-bold white foreground */
        fbcon->foreground = fbcon_ansi_colour ( fbcon, 0x7 );
        fbcon->bold = 0;
}

/**
 * Set default background colour
 *
 * @v fbcon             Frame buffer console
 */
static void fbcon_set_default_background ( struct fbcon *fbcon ) {

        /* Default to transparent background */
        fbcon->background = FBCON_TRANSPARENT;
}

/**
 * Get character cell
 *
 * @v fbcon             Frame buffer console
 * @v xpos              X position
 * @v ypos              Y position
 * @ret cell            Text cell
 */
static inline struct fbcon_text_cell * fbcon_cell ( struct fbcon *fbcon,
                                                    unsigned int xpos,
                                                    unsigned int ypos ) {
        unsigned int index;

        index = ( ( ypos * fbcon->character.width ) + xpos );
        return &fbcon->text.cells[index];
}

/**
 * Clear rows of characters
 *
 * @v fbcon             Frame buffer console
 * @v ypos              Starting Y position
 */
static void fbcon_clear ( struct fbcon *fbcon, unsigned int ypos ) {
        struct fbcon_text_cell *cell;
        unsigned int xpos;

        /* Clear stored character array */
        cell = fbcon_cell ( fbcon, 0, ypos );
        for ( ; ypos < fbcon->character.height ; ypos++ ) {
                for ( xpos = 0 ; xpos < fbcon->character.width ; xpos++ ) {
                        cell->foreground = fbcon->foreground;
                        cell->background = fbcon->background;
                        cell->character = ' ';
                        cell++;
                }
        }
}

/**
 * Draw character at specified position
 *
 * @v fbcon             Frame buffer console
 * @v cell              Text cell
 * @v xpos              X position
 * @v ypos              Y position
 */
static void fbcon_draw ( struct fbcon *fbcon, struct fbcon_text_cell *cell,
                         unsigned int xpos, unsigned int ypos ) {
        const uint8_t *glyph;
        size_t offset;
        size_t pixel_len;
        size_t skip_len;
        unsigned int row;
        unsigned int column;
        uint8_t bitmask;
        int transparent;
        const void *src;

        /* Get font character */
        glyph = fbcon->font->glyph ( cell->character );

        /* Calculate pixel geometry */
        offset = ( fbcon->indent +
                   ( ypos * fbcon->character.stride ) +
                   ( xpos * fbcon->character.len ) );
        pixel_len = fbcon->pixel->len;
        skip_len = ( fbcon->pixel->stride - fbcon->character.len );

        /* Check for transparent background colour */
        transparent = ( cell->background == FBCON_TRANSPARENT );

        /* Draw character rows */
        for ( row = 0 ; row < fbcon->font->height ; row++ ) {

                /* Draw background picture, if applicable */
                if ( transparent ) {
                        if ( fbcon->picture.start ) {
                                memcpy ( ( fbcon->start + offset ),
                                         ( fbcon->picture.start + offset ),
                                         fbcon->character.len );
                        } else {
                                memset ( ( fbcon->start + offset ), 0,
                                         fbcon->character.len );
                        }
                }

                /* Draw character row */
                for ( column = FBCON_CHAR_WIDTH, bitmask = glyph[row] ;
                      column ; column--, bitmask <<= 1, offset += pixel_len ) {
                        if ( bitmask & 0x80 ) {
                                src = &cell->foreground;
                        } else if ( ! transparent ) {
                                src = &cell->background;
                        } else {
                                continue;
                        }
                        memcpy ( ( fbcon->start + offset ), src, pixel_len );
                }

                /* Move to next row */
                offset += skip_len;
        }
}

/**
 * Redraw all characters
 *
 * @v fbcon             Frame buffer console
 */
static void fbcon_redraw ( struct fbcon *fbcon ) {
        struct fbcon_text_cell *cell;
        unsigned int xpos;
        unsigned int ypos;

        /* Redraw characters */
        cell = fbcon_cell ( fbcon, 0, 0 );
        for ( ypos = 0 ; ypos < fbcon->character.height ; ypos++ ) {
                for ( xpos = 0 ; xpos < fbcon->character.width ; xpos++ ) {
                        fbcon_draw ( fbcon, cell, xpos, ypos );
                        cell++;
                }
        }
}

/**
 * Scroll screen
 *
 * @v fbcon             Frame buffer console
 */
static void fbcon_scroll ( struct fbcon *fbcon ) {
        const struct fbcon_text_cell *old;
        struct fbcon_text_cell *new;
        unsigned int xpos;
        unsigned int ypos;
        unsigned int character;
        uint32_t foreground;
        uint32_t background;

        /* Sanity check */
        assert ( fbcon->ypos == fbcon->character.height );

        /* Scroll up character array */
        new = fbcon_cell ( fbcon, 0, 0 );
        old = fbcon_cell ( fbcon, 0, 1 );
        for ( ypos = 0 ; ypos < ( fbcon->character.height - 1 ) ; ypos++ ) {
                for ( xpos = 0 ; xpos < fbcon->character.width ; xpos++ ) {
                        /* Redraw character (if changed) */
                        character = old->character;
                        foreground = old->foreground;
                        background = old->background;
                        if ( ( new->character != character ) ||
                             ( new->foreground != foreground ) ||
                             ( new->background != background ) ) {
                                new->character = character;
                                new->foreground = foreground;
                                new->background = background;
                                fbcon_draw ( fbcon, new, xpos, ypos );
                        }
                        new++;
                        old++;
                }
        }

        /* Clear bottom row */
        fbcon_clear ( fbcon, ypos );
        for ( xpos = 0 ; xpos < fbcon->character.width ; xpos++ )
                fbcon_draw ( fbcon, new++, xpos, ypos );

        /* Update cursor position */
        fbcon->ypos--;
}

/**
 * Draw character at cursor position
 *
 * @v fbcon             Frame buffer console
 * @v show_cursor       Show cursor
 */
static void fbcon_draw_cursor ( struct fbcon *fbcon, int show_cursor ) {
        struct fbcon_text_cell *cell;
        struct fbcon_text_cell cursor;

        cell = fbcon_cell ( fbcon, fbcon->xpos, fbcon->ypos );
        if ( show_cursor ) {
                cursor.background = fbcon->foreground;
                cursor.foreground =
                        ( ( fbcon->background == FBCON_TRANSPARENT ) ?
                          0 : fbcon->background );
                cursor.character = cell->character;
                cell = &cursor;
        }
        fbcon_draw ( fbcon, cell, fbcon->xpos, fbcon->ypos );
}

/**
 * Handle ANSI CUP (cursor position)
 *
 * @v ctx               ANSI escape sequence context
 * @v count             Parameter count
 * @v params[0]         Row (1 is top)
 * @v params[1]         Column (1 is left)
 */
static void fbcon_handle_cup ( struct ansiesc_context *ctx,
                               unsigned int count __unused, int params[] ) {
        struct fbcon *fbcon = container_of ( ctx, struct fbcon, ctx );
        int cx = ( params[1] - 1 );
        int cy = ( params[0] - 1 );

        fbcon_draw_cursor ( fbcon, 0 );
        fbcon->xpos = cx;
        if ( fbcon->xpos >= fbcon->character.width )
                fbcon->xpos = 0;
        fbcon->ypos = cy;
        if ( fbcon->ypos >= fbcon->character.height )
                fbcon->ypos = 0;
        fbcon_draw_cursor ( fbcon, fbcon->show_cursor );
}

/**
 * Handle ANSI ED (erase in page)
 *
 * @v ctx               ANSI escape sequence context
 * @v count             Parameter count
 * @v params[0]         Region to erase
 */
static void fbcon_handle_ed ( struct ansiesc_context *ctx,
                              unsigned int count __unused,
                              int params[] __unused ) {
        struct fbcon *fbcon = container_of ( ctx, struct fbcon, ctx );

        /* We assume that we always clear the whole screen */
        assert ( params[0] == ANSIESC_ED_ALL );

        /* Clear character array */
        fbcon_clear ( fbcon, 0 );

        /* Redraw all characters */
        fbcon_redraw ( fbcon );

        /* Reset cursor position */
        fbcon->xpos = 0;
        fbcon->ypos = 0;
        fbcon_draw_cursor ( fbcon, fbcon->show_cursor );
}

/**
 * Handle ANSI SGR (set graphics rendition)
 *
 * @v ctx               ANSI escape sequence context
 * @v count             Parameter count
 * @v params            List of graphic rendition aspects
 */
static void fbcon_handle_sgr ( struct ansiesc_context *ctx, unsigned int count,
                               int params[] ) {
        struct fbcon *fbcon = container_of ( ctx, struct fbcon, ctx );
        uint32_t *custom = NULL;
        uint32_t rgb;
        unsigned int end;
        unsigned int i;
        int aspect;

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

                /* Process aspect */
                aspect = params[i];
                if ( aspect == 0 ) {
                        fbcon_set_default_foreground ( fbcon );
                        fbcon_set_default_background ( fbcon );
                } else if ( aspect == 1 ) {
                        fbcon->bold = fbcon_colour ( fbcon, FBCON_BOLD );
                } else if ( aspect == 22 ) {
                        fbcon->bold = 0;
                } else if ( ( aspect >= 30 ) && ( aspect <= 37 ) ) {
                        fbcon->foreground =
                                fbcon_ansi_colour ( fbcon, aspect - 30 );
                } else if ( aspect == 38 ) {
                        custom = &fbcon->foreground;
                } else if ( aspect == 39 ) {
                        fbcon_set_default_foreground ( fbcon );
                } else if ( ( aspect >= 40 ) && ( aspect <= 47 ) ) {
                        fbcon->background =
                                fbcon_ansi_colour ( fbcon, aspect - 40 );
                } else if ( aspect == 48 ) {
                        custom = &fbcon->background;
                } else if ( aspect == 49 ) {
                        fbcon_set_default_background ( fbcon );
                }

                /* Process custom RGB colour, if applicable
                 *
                 * We support the xterm-compatible
                 * "<ESC>[38;2;<red>;<green>;<blue>m" and
                 * "<ESC>[48;2;<red>;<green>;<blue>m" sequences.
                 */
                if ( custom ) {
                        rgb = 0;
                        end = ( i + 5 );
                        for ( ; ( i < count ) && ( i < end ) ; i++ )
                                rgb = ( ( rgb << 8 ) | params[i] );
                        *custom = fbcon_colour ( fbcon, rgb );
                        custom = NULL;
                }
        }
}

/**
 * Handle ANSI DECTCEM set (show cursor)
 *
 * @v ctx               ANSI escape sequence context
 * @v count             Parameter count
 * @v params            List of graphic rendition aspects
 */
static void fbcon_handle_dectcem_set ( struct ansiesc_context *ctx,
                                       unsigned int count __unused,
                                       int params[] __unused ) {
        struct fbcon *fbcon = container_of ( ctx, struct fbcon, ctx );

        fbcon->show_cursor = 1;
        fbcon_draw_cursor ( fbcon, 1 );
}

/**
 * Handle ANSI DECTCEM reset (hide cursor)
 *
 * @v ctx               ANSI escape sequence context
 * @v count             Parameter count
 * @v params            List of graphic rendition aspects
 */
static void fbcon_handle_dectcem_reset ( struct ansiesc_context *ctx,
                                         unsigned int count __unused,
                                         int params[] __unused ) {
        struct fbcon *fbcon = container_of ( ctx, struct fbcon, ctx );

        fbcon->show_cursor = 0;
        fbcon_draw_cursor ( fbcon, 0 );
}

/** ANSI escape sequence handlers */
static struct ansiesc_handler fbcon_ansiesc_handlers[] = {
        { ANSIESC_CUP, fbcon_handle_cup },
        { ANSIESC_ED, fbcon_handle_ed },
        { ANSIESC_SGR, fbcon_handle_sgr },
        { ANSIESC_DECTCEM_SET, fbcon_handle_dectcem_set },
        { ANSIESC_DECTCEM_RESET, fbcon_handle_dectcem_reset },
        { 0, NULL }
};

/**
 * Print a character to current cursor position
 *
 * @v fbcon             Frame buffer console
 * @v character         Character
 */
void fbcon_putchar ( struct fbcon *fbcon, int character ) {
        struct fbcon_text_cell *cell;

        /* Intercept ANSI escape sequences */
        character = ansiesc_process ( &fbcon->ctx, character );
        if ( character < 0 )
                return;

        /* Accumulate Unicode characters */
        character = utf8_accumulate ( &fbcon->utf8, character );
        if ( character == 0 )
                return;

        /* Handle control characters */
        switch ( character ) {
        case '\r':
                fbcon_draw_cursor ( fbcon, 0 );
                fbcon->xpos = 0;
                break;
        case '\n':
                fbcon_draw_cursor ( fbcon, 0 );
                fbcon->xpos = 0;
                fbcon->ypos++;
                break;
        case '\b':
                fbcon_draw_cursor ( fbcon, 0 );
                if ( fbcon->xpos ) {
                        fbcon->xpos--;
                } else if ( fbcon->ypos ) {
                        fbcon->xpos = ( fbcon->character.width - 1 );
                        fbcon->ypos--;
                }
                break;
        default:
                /* Print character at current cursor position */
                cell = fbcon_cell ( fbcon, fbcon->xpos, fbcon->ypos );
                cell->foreground = ( fbcon->foreground | fbcon->bold );
                cell->background = fbcon->background;
                cell->character = character;
                fbcon_draw ( fbcon, cell, fbcon->xpos, fbcon->ypos );

                /* Advance cursor */
                fbcon->xpos++;
                if ( fbcon->xpos >= fbcon->character.width ) {
                        fbcon->xpos = 0;
                        fbcon->ypos++;
                }
                break;
        }

        /* Scroll screen if necessary */
        if ( fbcon->ypos >= fbcon->character.height )
                fbcon_scroll ( fbcon );

        /* Show cursor */
        fbcon_draw_cursor ( fbcon, fbcon->show_cursor );
}

/**
 * Initialise background picture
 *
 * @v fbcon             Frame buffer console
 * @v pixbuf            Background picture
 * @ret rc              Return status code
 */
static int fbcon_picture_init ( struct fbcon *fbcon,
                                struct pixel_buffer *pixbuf ) {
        struct fbcon_geometry *pixel = fbcon->pixel;
        struct fbcon_picture *picture = &fbcon->picture;
        size_t len;
        size_t indent;
        size_t offset;
        const uint32_t *rgb;
        uint32_t raw;
        unsigned int x;
        unsigned int y;
        unsigned int width;
        unsigned int height;
        int xgap;
        int ygap;
        int rc;

        /* Allocate buffer */
        len = ( pixel->height * pixel->stride );
        picture->start = umalloc ( len );
        if ( ! picture->start ) {
                DBGC ( fbcon, "FBCON %p could not allocate %zd bytes for "
                       "picture\n", fbcon, len );
                rc = -ENOMEM;
                goto err_umalloc;
        }

        /* Centre picture on console */
        xgap = ( ( ( int ) ( pixel->width - pixbuf->width ) ) / 2 );
        ygap = ( ( ( int ) ( pixel->height - pixbuf->height ) ) / 2 );
        indent = ( ( ( ( ygap >= 0 ) ? ygap : 0 ) * pixel->stride ) +
                   ( ( ( xgap >= 0 ) ? xgap : 0 ) * pixel->len ) );
        width = pixbuf->width;
        if ( width > pixel->width )
                width = pixel->width;
        height = pixbuf->height;
        if ( height > pixel->height )
                height = pixel->height;
        DBGC ( fbcon, "FBCON %p picture is pixel %dx%d at [%d,%d),[%d,%d)\n",
               fbcon, width, height, xgap, ( xgap + pixbuf->width ), ygap,
               ( ygap + pixbuf->height ) );

        /* Convert to frame buffer raw format */
        memset ( picture->start, 0, len );
        for ( y = 0 ; y < height ; y++ ) {
                offset = ( indent + ( y * pixel->stride ) );
                rgb = pixbuf_pixel ( pixbuf, ( ( xgap < 0 ) ? -xgap : 0 ),
                                     ( ( ( ygap < 0 ) ? -ygap : 0 ) + y ) );
                for ( x = 0 ; x < width ; x++ ) {
                        raw = fbcon_colour ( fbcon, *rgb );
                        memcpy ( ( picture->start + offset ), &raw,
                                 pixel->len );
                        offset += pixel->len;
                        rgb++;
                }
        }

        return 0;

        ufree ( picture->start );
 err_umalloc:
        return rc;
}

/**
 * Initialise frame buffer console
 *
 * @v fbcon             Frame buffer console
 * @v start             Start address
 * @v pixel             Pixel geometry
 * @v map               Colour mapping
 * @v font              Font definition
 * @v config            Console configuration
 * @ret rc              Return status code
 */
int fbcon_init ( struct fbcon *fbcon, void *start,
                 struct fbcon_geometry *pixel,
                 struct fbcon_colour_map *map,
                 struct fbcon_font *font,
                 struct console_configuration *config ) {
        int width;
        int height;
        unsigned int xgap;
        unsigned int ygap;
        unsigned int left;
        unsigned int right;
        unsigned int top;
        unsigned int bottom;
        int rc;

        /* Initialise data structure */
        memset ( fbcon, 0, sizeof ( *fbcon ) );
        fbcon->start = start;
        fbcon->pixel = pixel;
        assert ( pixel->len <= sizeof ( uint32_t ) );
        fbcon->map = map;
        fbcon->font = font;
        fbcon->ctx.handlers = fbcon_ansiesc_handlers;
        fbcon->show_cursor = 1;

        /* Derive overall length */
        fbcon->len = ( pixel->height * pixel->stride );
        DBGC ( fbcon, "FBCON %p at [%08lx,%08lx)\n", fbcon,
               virt_to_phys ( fbcon->start ),
               ( virt_to_phys ( fbcon->start ) + fbcon->len ) );

        /* Calculate margin.  If the actual screen size is larger than
         * the requested screen size, then update the margins so that
         * the margin remains relative to the requested screen size.
         * (As an exception, if a zero margin was specified then treat
         * this as meaning "expand to edge of actual screen".)
         */
        xgap = ( pixel->width - config->width );
        ygap = ( pixel->height - config->height );
        left = ( xgap / 2 );
        right = ( xgap - left );
        top = ( ygap / 2 );
        bottom = ( ygap - top );
        fbcon->margin.left = ( config->left + ( config->left ? left : 0 ) );
        fbcon->margin.right = ( config->right + ( config->right ? right : 0 ) );
        fbcon->margin.top = ( config->top + ( config->top ? top : 0 ) );
        fbcon->margin.bottom =
                ( config->bottom + ( config->bottom ? bottom : 0 ) );

        /* Expand margin to accommodate whole characters */
        width = ( pixel->width - fbcon->margin.left - fbcon->margin.right );
        height = ( pixel->height - fbcon->margin.top - fbcon->margin.bottom );
        if ( ( width < FBCON_CHAR_WIDTH ) ||
             ( height < ( ( int ) font->height ) ) ) {
                DBGC ( fbcon, "FBCON %p has unusable character area "
                       "[%d-%d),[%d-%d)\n", fbcon, fbcon->margin.left,
                       ( pixel->width - fbcon->margin.right ),
                       fbcon->margin.top,
                       ( pixel->height - fbcon->margin.bottom ) );
                rc = -EINVAL;
                goto err_margin;
        }
        xgap = ( width % FBCON_CHAR_WIDTH );
        ygap = ( height % font->height );
        fbcon->margin.left += ( xgap / 2 );
        fbcon->margin.top += ( ygap / 2 );
        fbcon->margin.right += ( xgap - ( xgap / 2 ) );
        fbcon->margin.bottom += ( ygap - ( ygap / 2 ) );
        fbcon->indent = ( ( fbcon->margin.top * pixel->stride ) +
                          ( fbcon->margin.left * pixel->len ) );

        /* Derive character geometry from pixel geometry */
        fbcon->character.width = ( width / FBCON_CHAR_WIDTH );
        fbcon->character.height = ( height / font->height );
        fbcon->character.len = ( pixel->len * FBCON_CHAR_WIDTH );
        fbcon->character.stride = ( pixel->stride * font->height );
        DBGC ( fbcon, "FBCON %p is pixel %dx%d, char %dx%d at "
               "[%d-%d),[%d-%d)\n", fbcon, fbcon->pixel->width,
               fbcon->pixel->height, fbcon->character.width,
               fbcon->character.height, fbcon->margin.left,
               ( fbcon->pixel->width - fbcon->margin.right ),
               fbcon->margin.top,
               ( fbcon->pixel->height - fbcon->margin.bottom ) );

        /* Set default colours */
        fbcon_set_default_foreground ( fbcon );
        fbcon_set_default_background ( fbcon );

        /* Allocate and initialise stored character array */
        fbcon->text.cells = umalloc ( fbcon->character.width *
                                      fbcon->character.height *
                                      sizeof ( fbcon->text.cells[0] ) );
        if ( ! fbcon->text.cells ) {
                rc = -ENOMEM;
                goto err_text;
        }
        fbcon_clear ( fbcon, 0 );

        /* Set framebuffer to all black (including margins) */
        memset ( fbcon->start, 0, fbcon->len );

        /* Generate pixel buffer from background image, if applicable */
        if ( config->pixbuf &&
             ( ( rc = fbcon_picture_init ( fbcon, config->pixbuf ) ) != 0 ) )
                goto err_picture;

        /* Draw background picture (including margins), if applicable */
        if ( fbcon->picture.start )
                memcpy ( fbcon->start, fbcon->picture.start, fbcon->len );

        /* Update console width and height */
        console_set_size ( fbcon->character.width, fbcon->character.height );

        return 0;

        ufree ( fbcon->picture.start );
 err_picture:
        ufree ( fbcon->text.cells );
 err_text:
 err_margin:
        return rc;
}

/**
 * Finalise frame buffer console
 *
 * @v fbcon             Frame buffer console
 */
void fbcon_fini ( struct fbcon *fbcon ) {

        ufree ( fbcon->text.cells );
        ufree ( fbcon->picture.start );
}