code.delx.au - refind/blob - filesystems/fsw_efi_lib.c

   1 /**
   2  * \file fsw_efi_lib.c
   3  * EFI host environment library functions.
   4  */
   5
   6 /*-
   7  * Copyright (c) 2006 Christoph Pfisterer
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions are
  11  * met:
  12  *
  13  *  * Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  *  * Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  *  * Neither the name of Christoph Pfisterer nor the names of the
  22  *    contributors may be used to endorse or promote products derived
  23  *    from this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "fsw_efi.h"
  39
  40
  41 //
  42 // time conversion
  43 //
  44 // Adopted from public domain code in FreeBSD libc.
  45 //
  46
  47 #define SECSPERMIN      60
  48 #define MINSPERHOUR     60
  49 #define HOURSPERDAY     24
  50 #define DAYSPERWEEK     7
  51 #define DAYSPERNYEAR    365
  52 #define DAYSPERLYEAR    366
  53 #define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
  54 #define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
  55 #define MONSPERYEAR     12
  56
  57 #define EPOCH_YEAR      1970
  58 #define EPOCH_WDAY      TM_THURSDAY
  59
  60 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
  61 #define LEAPS_THRU_END_OF(y)    ((y) / 4 - (y) / 100 + (y) / 400)
  62
  63 static const int mon_lengths[2][MONSPERYEAR] = {
  64     { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
  65     { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
  66 };
  67 static const int year_lengths[2] = {
  68     DAYSPERNYEAR, DAYSPERLYEAR
  69 };
  70
  71 VOID fsw_efi_decode_time(OUT EFI_TIME *EfiTime, IN UINT32 UnixTime)
  72 {
  73     long        days, rem;
  74     int         y, newy, yleap;
  75     const int   *ip;
  76
  77     ZeroMem(EfiTime, sizeof(EFI_TIME));
  78
  79     days = UnixTime / SECSPERDAY;
  80     rem = UnixTime % SECSPERDAY;
  81
  82     EfiTime->Hour = (UINT8) (rem / SECSPERHOUR);
  83     rem = rem % SECSPERHOUR;
  84     EfiTime->Minute = (UINT8) (rem / SECSPERMIN);
  85     EfiTime->Second = (UINT8) (rem % SECSPERMIN);
  86
  87     y = EPOCH_YEAR;
  88     while (days < 0 || days >= (long) year_lengths[yleap = isleap(y)]) {
  89         newy = y + days / DAYSPERNYEAR;
  90         if (days < 0)
  91             --newy;
  92         days -= (newy - y) * DAYSPERNYEAR +
  93             LEAPS_THRU_END_OF(newy - 1) -
  94             LEAPS_THRU_END_OF(y - 1);
  95         y = newy;
  96     }
  97     EfiTime->Year = (UINT16)y;
  98     ip = mon_lengths[yleap];
  99     for (EfiTime->Month = 0; days >= (long) ip[EfiTime->Month]; ++(EfiTime->Month))
 100         days = days - (long) ip[EfiTime->Month];
 101     EfiTime->Month++;  // adjust range to EFI conventions
 102     EfiTime->Day = (UINT8) (days + 1);
 103 }
 104
 105 //
 106 // String functions, used for file and volume info
 107 //
 108
 109 UINTN fsw_efi_strsize(struct fsw_string *s)
 110 {
 111     if (s->type == FSW_STRING_TYPE_EMPTY)
 112         return sizeof(CHAR16);
 113     return (s->len + 1) * sizeof(CHAR16);
 114 }
 115
 116 VOID fsw_efi_strcpy(CHAR16 *Dest, struct fsw_string *src)
 117 {
 118     if (src->type == FSW_STRING_TYPE_EMPTY | src->size == 0) {
 119         Dest[0] = 0;
 120     } else if (src->type == FSW_STRING_TYPE_UTF16) {
 121         CopyMem(Dest, src->data, src->size);
 122         Dest[src->len] = 0;
 123     } else {
 124         // TODO: coerce, recurse
 125         Dest[0] = 0;
 126     }
 127 }
 128
 129 // EOF