/* $Id: fsw_efi_lib.c 98103 2023-01-17 14:15:46Z vboxsync $ */
/** @file
 * fsw_efi_lib.c - EFI host environment library functions.
 */

/*
 * Copyright (C) 2010-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * 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, in version 3 of the
 * License.
 *
 * 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, see <https://www.gnu.org/licenses>.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
 * in the VirtualBox distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 *
 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
 * ---------------------------------------------------------------------------
 * This code is based on:
 *
 * Copyright (c) 2006 Christoph Pfisterer
 *
 * 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.
 *
 *  * Neither the name of Christoph Pfisterer nor the names of the
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 COPYRIGHT
 * OWNER OR CONTRIBUTORS 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.
 */

#include "fsw_efi.h"


//
// time conversion
//
// Adopted from public domain code in FreeBSD libc.
//

#define SECSPERMIN      60
#define MINSPERHOUR     60
#define HOURSPERDAY     24
#define DAYSPERWEEK     7
#define DAYSPERNYEAR    365
#define DAYSPERLYEAR    366
#define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR     12

#define EPOCH_YEAR      1970
#define EPOCH_WDAY      TM_THURSDAY

#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
#define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)

static const int mon_lengths[2][MONSPERYEAR] = {
    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
    { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
};
static const int year_lengths[2] = {
    DAYSPERNYEAR, DAYSPERLYEAR
};

VOID fsw_efi_decode_time(OUT EFI_TIME *EfiTime, IN UINT32 UnixTime)
{
    long        days, rem;
    int         y, newy, yleap;
    const int   *ip;

    ZeroMem(EfiTime, sizeof(EFI_TIME));

    days = UnixTime / SECSPERDAY;
    rem = UnixTime % SECSPERDAY;

    EfiTime->Hour = (UINT8) (rem / SECSPERHOUR);
    rem = rem % SECSPERHOUR;
    EfiTime->Minute = (UINT8) (rem / SECSPERMIN);
    EfiTime->Second = (UINT8) (rem % SECSPERMIN);

    y = EPOCH_YEAR;
    while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
        newy = y + days / DAYSPERNYEAR;
        if (days < 0)
            --newy;
        days -= (newy - y) * DAYSPERNYEAR +
            LEAPS_THRU_END_OF(newy - 1) -
            LEAPS_THRU_END_OF(y - 1);
        y = newy;
    }
    EfiTime->Year = (UINT16)y;
    ip = mon_lengths[yleap];
    for (EfiTime->Month = 0; days >= (long) ip[EfiTime->Month]; ++(EfiTime->Month))
        days = days - (long) ip[EfiTime->Month];
    EfiTime->Month++;  // adjust range to EFI conventions
    EfiTime->Day = (UINT8) (days + 1);
}

//
// String functions, used for file and volume info
//

UINTN fsw_efi_strsize(struct fsw_string *s)
{
    if (s->type == FSW_STRING_TYPE_EMPTY)
        return sizeof(CHAR16);
    return (s->len + 1) * sizeof(CHAR16);
}

VOID fsw_efi_strcpy(CHAR16 *Dest, struct fsw_string *src)
{
    if (src->type == FSW_STRING_TYPE_EMPTY) {
        Dest[0] = 0;
    } else if (src->type == FSW_STRING_TYPE_UTF16) {
        CopyMem(Dest, src->data, src->size);
        Dest[src->len] = 0;
    } else {
        /// @todo coerce, recurse
        Dest[0] = 0;
    }
}

#ifdef VBOX
int fsw_streq_ISO88591_UTF16(void *s1data, void *s2data, int len)
{
    int i;
    fsw_u8 *p1 = (fsw_u8 *)s1data;
    fsw_u16 *p2 = (fsw_u16 *)s2data;

    for (i = 0; i<len; i++)
    {
        if (fsw_to_lower(p1[i]) != fsw_to_lower(p2[i]))
        {
            return 0;
        }
    }

    return 1;
}
#endif

// EOF