efi_console.c

Go to the documentation of this file.

/*
 * Copyright (C) 2008 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

FILE_LICENCE ( GPL2_OR_LATER );

#include <stddef.h>
#include <assert.h>
#include <gpxe/efi/efi.h>
#include <gpxe/ansiesc.h>
#include <console.h>

#define ATTR_BOLD               0x08

#define ATTR_FCOL_MASK          0x07
#define ATTR_FCOL_BLACK         0x00
#define ATTR_FCOL_BLUE          0x01
#define ATTR_FCOL_GREEN         0x02
#define ATTR_FCOL_CYAN          0x03
#define ATTR_FCOL_RED           0x04
#define ATTR_FCOL_MAGENTA       0x05
#define ATTR_FCOL_YELLOW        0x06
#define ATTR_FCOL_WHITE         0x07

#define ATTR_BCOL_MASK          0x70
#define ATTR_BCOL_BLACK         0x00
#define ATTR_BCOL_BLUE          0x10
#define ATTR_BCOL_GREEN         0x20
#define ATTR_BCOL_CYAN          0x30
#define ATTR_BCOL_RED           0x40
#define ATTR_BCOL_MAGENTA       0x50
#define ATTR_BCOL_YELLOW        0x60
#define ATTR_BCOL_WHITE         0x70

#define ATTR_DEFAULT            ATTR_FCOL_WHITE

/** Current character attribute */
static unsigned int efi_attr = ATTR_DEFAULT;

/**
 * Handle ANSI CUP (cursor position)
 *
 * @v count             Parameter count
 * @v params[0]         Row (1 is top)
 * @v params[1]         Column (1 is left)
 */
static void efi_handle_cup ( unsigned int count __unused, int params[] ) {
        EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *conout = efi_systab->ConOut;
        int cx = ( params[1] - 1 );
        int cy = ( params[0] - 1 );

        if ( cx < 0 )
                cx = 0;
        if ( cy < 0 )
                cy = 0;

        conout->SetCursorPosition ( conout, cx, cy );
}

/**
 * Handle ANSI ED (erase in page)
 *
 * @v count             Parameter count
 * @v params[0]         Region to erase
 */
static void efi_handle_ed ( unsigned int count __unused,
                             int params[] __unused ) {
        EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *conout = efi_systab->ConOut;

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

        conout->ClearScreen ( conout );
}

/**
 * Handle ANSI SGR (set graphics rendition)
 *
 * @v count             Parameter count
 * @v params            List of graphic rendition aspects
 */
static void efi_handle_sgr ( unsigned int count, int params[] ) {
        EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *conout = efi_systab->ConOut;
        static const uint8_t efi_attr_fcols[10] = {
                ATTR_FCOL_BLACK, ATTR_FCOL_RED, ATTR_FCOL_GREEN,
                ATTR_FCOL_YELLOW, ATTR_FCOL_BLUE, ATTR_FCOL_MAGENTA,
                ATTR_FCOL_CYAN, ATTR_FCOL_WHITE,
                ATTR_FCOL_WHITE, ATTR_FCOL_WHITE /* defaults */
        };
        static const uint8_t efi_attr_bcols[10] = {
                ATTR_BCOL_BLACK, ATTR_BCOL_RED, ATTR_BCOL_GREEN,
                ATTR_BCOL_YELLOW, ATTR_BCOL_BLUE, ATTR_BCOL_MAGENTA,
                ATTR_BCOL_CYAN, ATTR_BCOL_WHITE,
                ATTR_BCOL_BLACK, ATTR_BCOL_BLACK /* defaults */
        };
        unsigned int i;
        int aspect;

        for ( i = 0 ; i < count ; i++ ) {
                aspect = params[i];
                if ( aspect == 0 ) {
                        efi_attr = ATTR_DEFAULT;
                } else if ( aspect == 1 ) {
                        efi_attr |= ATTR_BOLD;
                } else if ( aspect == 22 ) {
                        efi_attr &= ~ATTR_BOLD;
                } else if ( ( aspect >= 30 ) && ( aspect <= 39 ) ) {
                        efi_attr &= ~ATTR_FCOL_MASK;
                        efi_attr |= efi_attr_fcols[ aspect - 30 ];
                } else if ( ( aspect >= 40 ) && ( aspect <= 49 ) ) {
                        efi_attr &= ~ATTR_BCOL_MASK;
                        efi_attr |= efi_attr_bcols[ aspect - 40 ];
                }
        }

        conout->SetAttribute ( conout, efi_attr );
}

/** EFI console ANSI escape sequence handlers */
static struct ansiesc_handler efi_ansiesc_handlers[] = {
        { ANSIESC_CUP, efi_handle_cup },
        { ANSIESC_ED, efi_handle_ed },
        { ANSIESC_SGR, efi_handle_sgr },
        { 0, NULL }
};

/** EFI console ANSI escape sequence context */
static struct ansiesc_context efi_ansiesc_ctx = {
        .handlers = efi_ansiesc_handlers,
};

/**
 * Print a character to EFI console
 *
 * @v character         Character to be printed
 */
static void efi_putchar ( int character ) {
        EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *conout = efi_systab->ConOut;
        wchar_t wstr[] = { character, 0 };

        /* Intercept ANSI escape sequences */
        character = ansiesc_process ( &efi_ansiesc_ctx, character );
        if ( character < 0 )
                return;

        conout->OutputString ( conout, wstr );
}

/**
 * Pointer to current ANSI output sequence
 *
 * While we are in the middle of returning an ANSI sequence for a
 * special key, this will point to the next character to return.  When
 * not in the middle of such a sequence, this will point to a NUL
 * (note: not "will be NULL").
 */
static const char *ansi_input = "";

/** Mapping from EFI scan codes to ANSI escape sequences */
static const char *ansi_sequences[] = {
        [SCAN_UP] = "[A",
        [SCAN_DOWN] = "[B",
        [SCAN_RIGHT] = "[C",
        [SCAN_LEFT] = "[D",
        [SCAN_HOME] = "[H",
        [SCAN_END] = "[F",
        [SCAN_INSERT] = "[2~",
        /* EFI translates an incoming backspace via the serial console
         * into a SCAN_DELETE.  There's not much we can do about this.
         */
        [SCAN_DELETE] = "[3~",
        [SCAN_PAGE_UP] = "[5~",
        [SCAN_PAGE_DOWN] = "[6~",
        /* EFI translates some (but not all) incoming escape sequences
         * via the serial console into equivalent scancodes.  When it
         * doesn't recognise a sequence, it helpfully(!) translates
         * the initial ESC and passes the remainder through verbatim.
         * Treating SCAN_ESC as equivalent to an empty escape sequence
         * works around this bug.
         */
        [SCAN_ESC] = "",
};

/**
 * Get ANSI escape sequence corresponding to EFI scancode
 *
 * @v scancode          EFI scancode
 * @ret ansi_seq        ANSI escape sequence, if any, otherwise NULL
 */
static const char * scancode_to_ansi_seq ( unsigned int scancode ) {
        if ( scancode < ( sizeof ( ansi_sequences ) /
                          sizeof ( ansi_sequences[0] ) ) ) {
                return ansi_sequences[scancode];
        }
        return NULL;
}

/**
 * Get character from EFI console
 *
 * @ret character       Character read from console
 */
static int efi_getchar ( void ) {
        EFI_SIMPLE_TEXT_INPUT_PROTOCOL *conin = efi_systab->ConIn;
        const char *ansi_seq;
        EFI_INPUT_KEY key;
        EFI_STATUS efirc;

        /* If we are mid-sequence, pass out the next byte */
        if ( *ansi_input )
                return *(ansi_input++);

        /* Read key from real EFI console */
        if ( ( efirc = conin->ReadKeyStroke ( conin, &key ) ) != 0 ) {
                DBG ( "EFI could not read keystroke: %s\n",
                      efi_strerror ( efirc ) );
                return 0;
        }
        DBG2 ( "EFI read key stroke with unicode %04x scancode %04x\n",
               key.UnicodeChar, key.ScanCode );

        /* If key has a Unicode representation, return it */
        if ( key.UnicodeChar )
                return key.UnicodeChar;

        /* Otherwise, check for a special key that we know about */
        if ( ( ansi_seq = scancode_to_ansi_seq ( key.ScanCode ) ) ) {
                /* Start of escape sequence: return ESC (0x1b) */
                ansi_input = ansi_seq;
                return 0x1b;
        }

        return 0;
}

/**
 * Check for character ready to read from EFI console
 *
 * @ret True            Character available to read
 * @ret False           No character available to read
 */
static int efi_iskey ( void ) {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        EFI_SIMPLE_TEXT_INPUT_PROTOCOL *conin = efi_systab->ConIn;
        EFI_STATUS efirc;

        /* If we are mid-sequence, we are always ready */
        if ( *ansi_input )
                return 1;

        /* Check to see if the WaitForKey event has fired */
        if ( ( efirc = bs->CheckEvent ( conin->WaitForKey ) ) == 0 )
                return 1;

        return 0;
}

struct console_driver efi_console __console_driver = {
        .putchar = efi_putchar,
        .getchar = efi_getchar,
        .iskey = efi_iskey,
};