efi_fbcon.c

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/*
 * Copyright (C) 2015 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
 *
 * EFI frame buffer console
 *
 */

#include <string.h>
#include <strings.h>
#include <ctype.h>
#include <errno.h>
#include <assert.h>
#include <limits.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/Protocol/GraphicsOutput.h>
#include <ipxe/efi/Protocol/HiiFont.h>
#include <ipxe/ansicol.h>
#include <ipxe/fbcon.h>
#include <ipxe/console.h>
#include <ipxe/uaccess.h>
#include <ipxe/umalloc.h>
#include <ipxe/rotate.h>
#include <config/console.h>

/* Avoid dragging in EFI console if not otherwise used */
extern struct console_driver efi_console;
struct console_driver efi_console __attribute__ (( weak ));

/* Set default console usage if applicable
 *
 * We accept either CONSOLE_FRAMEBUFFER or CONSOLE_EFIFB.
 */
#if ( defined ( CONSOLE_FRAMEBUFFER ) && ! defined ( CONSOLE_EFIFB ) )
#define CONSOLE_EFIFB CONSOLE_FRAMEBUFFER
#endif
#if ! ( defined ( CONSOLE_EFIFB ) && CONSOLE_EXPLICIT ( CONSOLE_EFIFB ) )
#undef CONSOLE_EFIFB
#define CONSOLE_EFIFB ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
#endif

/** Number of ASCII glyphs in cache */
#define EFIFB_ASCII 128

/** Number of dynamic non-ASCII glyphs in cache */
#define EFIFB_DYNAMIC 32

/* Forward declaration */
struct console_driver efifb_console __console_driver;

/** An EFI frame buffer */
struct efifb {
        /** EFI graphics output protocol */
        EFI_GRAPHICS_OUTPUT_PROTOCOL *gop;
        /** EFI HII font protocol */
        EFI_HII_FONT_PROTOCOL *hiifont;
        /** Saved mode */
        UINT32 saved_mode;

        /** Frame buffer console */
        struct fbcon fbcon;
        /** Physical start address */
        physaddr_t start;
        /** Pixel geometry */
        struct fbcon_geometry pixel;
        /** Colour mapping */
        struct fbcon_colour_map map;
        /** Font definition */
        struct fbcon_font font;
        /** Character glyph cache */
        uint8_t *glyphs;
        /** Dynamic characters in cache */
        unsigned int dynamic[EFIFB_DYNAMIC];
        /** Next dynamic character cache entry to evict */
        unsigned int next;
};

/** The EFI frame buffer */
static struct efifb efifb;

/**
 * Draw character glyph
 *
 * @v character         Character
 * @v index             Index within glyph cache
 * @v toggle            Bits to toggle in each bitmask
 * @ret height          Character height, or negative error
 */
static int efifb_draw ( unsigned int character, unsigned int index,
                        unsigned int toggle ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        EFI_IMAGE_OUTPUT *blt;
        EFI_GRAPHICS_OUTPUT_BLT_PIXEL *pixel;
        unsigned int height;
        unsigned int x;
        unsigned int y;
        uint8_t *glyph;
        uint8_t bitmask;
        EFI_STATUS efirc;
        int rc;

        /* Clear existing glyph */
        glyph = &efifb.glyphs[ index * efifb.font.height ];
        memset ( glyph, 0, efifb.font.height );

        /* Get glyph */
        blt = NULL;
        if ( ( efirc = efifb.hiifont->GetGlyph ( efifb.hiifont, character,
                                                 NULL, &blt, NULL ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( &efifb, "EFIFB could not get glyph %#02x: %s\n",
                       character, strerror ( rc ) );
                goto err_get;
        }
        assert ( blt != NULL );

        /* Sanity check */
        if ( blt->Width > 8 ) {
                DBGC ( &efifb, "EFIFB glyph %#02x invalid width %d\n",
                       character, blt->Width );
                rc = -EINVAL;
                goto err_width;
        }

        /* Convert glyph to bitmap */
        pixel = blt->Image.Bitmap;
        height = blt->Height;
        for ( y = 0 ; ( ( y < height ) && ( y < efifb.font.height ) ) ; y++ ) {
                bitmask = 0;
                for ( x = 0 ; x < blt->Width ; x++ ) {
                        bitmask = rol8 ( bitmask, 1 );
                        if ( pixel->Blue || pixel->Green || pixel->Red )
                                bitmask |= 0x01;
                        pixel++;
                }
                bitmask ^= toggle;
                *(glyph++) = bitmask;
        }

        /* Free glyph */
        bs->FreePool ( blt );

        return height;

 err_width:
        bs->FreePool ( blt );
 err_get:
        return rc;
}

/**
 * Draw "unknown character" glyph
 *
 * @v index             Index within glyph cache
 * @ret rc              Return status code
 */
static int efifb_draw_unknown ( unsigned int index ) {

        /* Draw an inverted '?' glyph */
        return efifb_draw ( '?', index, -1U );
}

/**
 * Get dynamic glyph index
 *
 * @v character         Unicode character
 * @ret index           Glyph cache index
 */
static unsigned int efifb_dynamic ( unsigned int character ) {
        unsigned int dynamic;
        unsigned int index;
        unsigned int i;
        int height;

        /* Search existing cached entries */
        for ( i = 0 ; i < EFIFB_DYNAMIC ; i++ ) {
                if ( character == efifb.dynamic[i] )
                        return ( EFIFB_ASCII + i );
        }

        /* Overwrite the oldest cache entry */
        dynamic = ( efifb.next++ % EFIFB_DYNAMIC );
        index = ( EFIFB_ASCII + dynamic );
        DBGC2 ( &efifb, "EFIFB dynamic %#02x is glyph %#02x\n",
                dynamic, character );

        /* Draw glyph */
        height = efifb_draw ( character, index, 0 );
        if ( height < 0 )
                efifb_draw_unknown ( index );

        /* Record cached character */
        efifb.dynamic[dynamic] = character;

        return index;
}

/**
 * Get character glyph
 *
 * @v character         Unicode character
 * @ret glyph           Character glyph to fill in
 */
static const uint8_t * efifb_glyph ( unsigned int character ) {
        unsigned int index;

        /* Identify glyph */
        if ( character < EFIFB_ASCII ) {

                /* ASCII character: use fixed cache entry */
                index = character;

        } else {

                /* Non-ASCII character: use dynamic glyph cache */
                index = efifb_dynamic ( character );
        }

        /* Return cached glyph */
        return &efifb.glyphs[ index * efifb.font.height ];
}

/**
 * Get character glyphs
 *
 * @ret rc              Return status code
 */
static int efifb_glyphs ( void ) {
        unsigned int character;
        int height;
        int max;
        size_t len;
        int rc;

        /* Get font height.  The GetFontInfo() call nominally returns
         * this information in an EFI_FONT_DISPLAY_INFO structure, but
         * is known to fail on many UEFI implementations.  Instead, we
         * iterate over all printable characters to find the maximum
         * height.
         */
        efifb.font.height = 0;
        max = 0;
        for ( character = 0 ; character < EFIFB_ASCII ; character++ ) {

                /* Skip non-printable characters */
                if ( ! isprint ( character ) )
                        continue;

                /* Get glyph */
                height = efifb_draw ( character, 0, 0 );
                if ( height < 0 ) {
                        rc = height;
                        goto err_height;
                }

                /* Calculate maximum height */
                if ( max < height )
                        max = height;
        }
        if ( ! max ) {
                DBGC ( &efifb, "EFIFB could not get font height\n" );
                return -ENOENT;
        }
        efifb.font.height = max;

        /* Allocate glyph data */
        len = ( ( EFIFB_ASCII + EFIFB_DYNAMIC ) * efifb.font.height );
        efifb.glyphs = umalloc ( len );
        if ( ! efifb.glyphs ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        memset ( efifb.glyphs, 0, len );

        /* Get font data */
        for ( character = 0 ; character < EFIFB_ASCII ; character++ ) {

                /* Skip non-printable characters */
                if ( ! isprint ( character ) ) {
                        efifb_draw_unknown ( character );
                        continue;
                }

                /* Get glyph */
                height = efifb_draw ( character, character, 0 );
                if ( height < 0 ) {
                        rc = height;
                        goto err_draw;
                }
        }

        /* Clear dynamic glyph character cache */
        memset ( efifb.dynamic, 0, sizeof ( efifb.dynamic ) );

        efifb.font.glyph = efifb_glyph;
        return 0;

 err_draw:
        ufree ( efifb.glyphs );
 err_alloc:
 err_height:
        return rc;
}

/**
 * Generate colour mapping for a single colour component
 *
 * @v mask              Mask value
 * @v scale             Scale value to fill in
 * @v lsb               LSB value to fill in
 * @ret rc              Return status code
 */
static int efifb_colour_map_mask ( uint32_t mask, uint8_t *scale,
                                   uint8_t *lsb ) {
        uint32_t check;

        /* Fill in LSB and scale */
        *lsb = ( mask ? ( ffs ( mask ) - 1 ) : 0 );
        *scale = ( mask ? ( 8 - ( fls ( mask ) - *lsb ) ) : 8 );

        /* Check that original mask was contiguous */
        check = ( ( 0xff >> *scale ) << *lsb );
        if ( check != mask )
                return -ENOTSUP;

        return 0;
}

/**
 * Generate colour mapping
 *
 * @v info              EFI mode information
 * @v map               Colour mapping to fill in
 * @ret bpp             Number of bits per pixel, or negative error
 */
static int efifb_colour_map ( EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info,
                              struct fbcon_colour_map *map ) {
        static EFI_PIXEL_BITMASK rgb_mask = {
                0x000000ffUL, 0x0000ff00UL, 0x00ff0000UL, 0xff000000UL
        };
        static EFI_PIXEL_BITMASK bgr_mask = {
                0x00ff0000UL, 0x0000ff00UL, 0x000000ffUL, 0xff000000UL
        };
        EFI_PIXEL_BITMASK *mask;
        uint8_t reserved_scale;
        uint8_t reserved_lsb;
        int rc;

        /* Determine applicable mask */
        switch ( info->PixelFormat ) {
        case PixelRedGreenBlueReserved8BitPerColor:
                mask = &rgb_mask;
                break;
        case PixelBlueGreenRedReserved8BitPerColor:
                mask = &bgr_mask;
                break;
        case PixelBitMask:
                mask = &info->PixelInformation;
                break;
        default:
                DBGC ( &efifb, "EFIFB unrecognised pixel format %d\n",
                       info->PixelFormat );
                return -ENOTSUP;
        }

        /* Map each colour component */
        if ( ( rc = efifb_colour_map_mask ( mask->RedMask, &map->red_scale,
                                            &map->red_lsb ) ) != 0 )
                return rc;
        if ( ( rc = efifb_colour_map_mask ( mask->GreenMask, &map->green_scale,
                                            &map->green_lsb ) ) != 0 )
                return rc;
        if ( ( rc = efifb_colour_map_mask ( mask->BlueMask, &map->blue_scale,
                                            &map->blue_lsb ) ) != 0 )
                return rc;
        if ( ( rc = efifb_colour_map_mask ( mask->ReservedMask, &reserved_scale,
                                            &reserved_lsb ) ) != 0 )
                return rc;

        /* Calculate total number of bits per pixel */
        return ( 32 - ( reserved_scale + map->red_scale + map->green_scale +
                        map->blue_scale ) );
}

/**
 * Select video mode
 *
 * @v min_width         Minimum required width (in pixels)
 * @v min_height        Minimum required height (in pixels)
 * @v min_bpp           Minimum required colour depth (in bits per pixel)
 * @ret mode_number     Mode number, or negative error
 */
static int efifb_select_mode ( unsigned int min_width, unsigned int min_height,
                               unsigned int min_bpp ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        struct fbcon_colour_map map;
        EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info;
        int best_mode_number = -ENOENT;
        unsigned int best_score = INT_MAX;
        unsigned int score;
        unsigned int mode;
        int bpp;
        UINTN size;
        EFI_STATUS efirc;
        int rc;

        /* Find the best mode */
        for ( mode = 0 ; mode < efifb.gop->Mode->MaxMode ; mode++ ) {

                /* Get mode information */
                if ( ( efirc = efifb.gop->QueryMode ( efifb.gop, mode, &size,
                                                      &info ) ) != 0 ) {
                        rc = -EEFI ( efirc );
                        DBGC ( &efifb, "EFIFB could not get mode %d "
                               "information: %s\n", mode, strerror ( rc ) );
                        goto err_query;
                }

                /* Skip unusable modes */
                bpp = efifb_colour_map ( info, &map );
                if ( bpp < 0 ) {
                        rc = bpp;
                        DBGC ( &efifb, "EFIFB could not build colour map for "
                               "mode %d: %s\n", mode, strerror ( rc ) );
                        goto err_map;
                }

                /* Skip modes not meeting the requirements */
                if ( ( info->HorizontalResolution < min_width ) ||
                     ( info->VerticalResolution < min_height ) ||
                     ( ( ( unsigned int ) bpp ) < min_bpp ) ) {
                        goto err_requirements;
                }

                /* Select this mode if it has the best (i.e. lowest)
                 * score.  We choose the scoring system to favour
                 * modes close to the specified width and height;
                 * within modes of the same width and height we prefer
                 * a higher colour depth.
                 */
                score = ( ( info->HorizontalResolution *
                            info->VerticalResolution ) - bpp );
                if ( score < best_score ) {
                        best_mode_number = mode;
                        best_score = score;
                }

        err_requirements:
        err_map:
                bs->FreePool ( info );
        err_query:
                continue;
        }

        if ( best_mode_number < 0 )
                DBGC ( &efifb, "EFIFB found no suitable mode\n" );
        return best_mode_number;
}

/**
 * Restore video mode
 *
 * @v rc                Return status code
 */
static int efifb_restore ( void ) {
        EFI_STATUS efirc;
        int rc;

        /* Restore original mode */
        if ( ( efirc = efifb.gop->SetMode ( efifb.gop,
                                            efifb.saved_mode ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( &efifb, "EFIFB could not restore mode %d: %s\n",
                       efifb.saved_mode, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Initialise EFI frame buffer
 *
 * @v config            Console configuration, or NULL to reset
 * @ret rc              Return status code
 */
static int efifb_init ( struct console_configuration *config ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *info;
        void *interface;
        int mode;
        int bpp;
        EFI_STATUS efirc;
        int rc;

        /* Locate graphics output protocol */
        if ( ( efirc = bs->LocateProtocol ( &efi_graphics_output_protocol_guid,
                                            NULL, &interface ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( &efifb, "EFIFB could not locate graphics output "
                       "protocol: %s\n", strerror ( rc ) );
                goto err_locate_gop;
        }
        efifb.gop = interface;

        /* Locate HII font protocol */
        if ( ( efirc = bs->LocateProtocol ( &efi_hii_font_protocol_guid,
                                            NULL, &interface ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( &efifb, "EFIFB could not locate HII font protocol: %s\n",
                       strerror ( rc ) );
                goto err_locate_hiifont;
        }
        efifb.hiifont = interface;

        /* Locate glyphs */
        if ( ( rc = efifb_glyphs() ) != 0 )
                goto err_glyphs;

        /* Save original mode */
        efifb.saved_mode = efifb.gop->Mode->Mode;

        /* Select mode */
        if ( ( mode = efifb_select_mode ( config->width, config->height,
                                          config->depth ) ) < 0 ) {
                rc = mode;
                goto err_select_mode;
        }

        /* Set mode */
        if ( ( efirc = efifb.gop->SetMode ( efifb.gop, mode ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( &efifb, "EFIFB could not set mode %d: %s\n",
                       mode, strerror ( rc ) );
                goto err_set_mode;
        }
        info = efifb.gop->Mode->Info;

        /* Populate colour map */
        bpp = efifb_colour_map ( info, &efifb.map );
        if ( bpp < 0 ) {
                rc = bpp;
                DBGC ( &efifb, "EFIFB could not build colour map for "
                       "mode %d: %s\n", mode, strerror ( rc ) );
                goto err_map;
        }

        /* Populate pixel geometry */
        efifb.pixel.width = info->HorizontalResolution;
        efifb.pixel.height = info->VerticalResolution;
        efifb.pixel.len = ( ( bpp + 7 ) / 8 );
        efifb.pixel.stride = ( efifb.pixel.len * info->PixelsPerScanLine );

        /* Populate frame buffer address */
        efifb.start = efifb.gop->Mode->FrameBufferBase;
        DBGC ( &efifb, "EFIFB using mode %d (%dx%d %dbpp at %#08lx)\n",
               mode, efifb.pixel.width, efifb.pixel.height, bpp, efifb.start );

        /* Initialise frame buffer console */
        if ( ( rc = fbcon_init ( &efifb.fbcon, phys_to_virt ( efifb.start ),
                                 &efifb.pixel, &efifb.map, &efifb.font,
                                 config ) ) != 0 )
                goto err_fbcon_init;

        return 0;

        fbcon_fini ( &efifb.fbcon );
 err_fbcon_init:
 err_map:
        efifb_restore();
 err_set_mode:
 err_select_mode:
        ufree ( efifb.glyphs );
 err_glyphs:
 err_locate_hiifont:
 err_locate_gop:
        return rc;
}

/**
 * Finalise EFI frame buffer
 *
 */
static void efifb_fini ( void ) {

        /* Finalise frame buffer console */
        fbcon_fini ( &efifb.fbcon );

        /* Restore saved mode */
        efifb_restore();

        /* Free glyphs */
        ufree ( efifb.glyphs );
}

/**
 * Print a character to current cursor position
 *
 * @v character         Character
 */
static void efifb_putchar ( int character ) {

        fbcon_putchar ( &efifb.fbcon, character );
}

/**
 * Configure console
 *
 * @v config            Console configuration, or NULL to reset
 * @ret rc              Return status code
 */
static int efifb_configure ( struct console_configuration *config ) {
        int rc;

        /* Reset console, if applicable */
        if ( ! efifb_console.disabled ) {
                efifb_fini();
                efi_console.disabled &= ~CONSOLE_DISABLED_OUTPUT;
                ansicol_reset_magic();
        }
        efifb_console.disabled = CONSOLE_DISABLED;

        /* Do nothing more unless we have a usable configuration */
        if ( ( config == NULL ) ||
             ( config->width == 0 ) || ( config->height == 0 ) ) {
                return 0;
        }

        /* Initialise EFI frame buffer */
        if ( ( rc = efifb_init ( config ) ) != 0 )
                return rc;

        /* Mark console as enabled */
        efifb_console.disabled = 0;
        efi_console.disabled |= CONSOLE_DISABLED_OUTPUT;

        /* Set magic colour to transparent if we have a background picture */
        if ( config->pixbuf )
                ansicol_set_magic_transparent();

        return 0;
}

/** EFI graphics output protocol console driver */
struct console_driver efifb_console __console_driver = {
        .usage = CONSOLE_EFIFB,
        .putchar = efifb_putchar,
        .configure = efifb_configure,
        .disabled = CONSOLE_DISABLED,
};