EmbeddedPkg/Library/TimeBaseLib/TimeBaseLib.c

   1 /** @file
   2 *
   3 *  Copyright (c) 2016, Hisilicon Limited. All rights reserved.
   4 *  Copyright (c) 2016, Linaro Limited. All rights reserved.
   5 *
   6 *  SPDX-License-Identifier: BSD-2-Clause-Patent
   7 *
   8 **/
   9
  10 #include <Uefi/UefiBaseType.h>
  11 #include <Uefi/UefiSpec.h>
  12 #include <Library/DebugLib.h>
  13 #include <Library/TimeBaseLib.h>
  14
  15 /**
  16   Converts Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC) to EFI_TIME
  17  **/
  18 VOID
  19 EFIAPI
  20 EpochToEfiTime (
  21   IN  UINTN     EpochSeconds,
  22   OUT EFI_TIME  *Time
  23   )
  24 {
  25   UINTN         a;
  26   UINTN         b;
  27   UINTN         c;
  28   UINTN         d;
  29   UINTN         g;
  30   UINTN         j;
  31   UINTN         m;
  32   UINTN         y;
  33   UINTN         da;
  34   UINTN         db;
  35   UINTN         dc;
  36   UINTN         dg;
  37   UINTN         hh;
  38   UINTN         mm;
  39   UINTN         ss;
  40   UINTN         J;
  41
  42   J  = (EpochSeconds / 86400) + 2440588;
  43   j  = J + 32044;
  44   g  = j / 146097;
  45   dg = j % 146097;
  46   c  = (((dg / 36524) + 1) * 3) / 4;
  47   dc = dg - (c * 36524);
  48   b  = dc / 1461;
  49   db = dc % 1461;
  50   a  = (((db / 365) + 1) * 3) / 4;
  51   da = db - (a * 365);
  52   y  = (g * 400) + (c * 100) + (b * 4) + a;
  53   m  = (((da * 5) + 308) / 153) - 2;
  54   d  = da - (((m + 4) * 153) / 5) + 122;
  55
  56   Time->Year  = y - 4800 + ((m + 2) / 12);
  57   Time->Month = ((m + 2) % 12) + 1;
  58   Time->Day   = d + 1;
  59
  60   ss = EpochSeconds % 60;
  61   a  = (EpochSeconds - ss) / 60;
  62   mm = a % 60;
  63   b = (a - mm) / 60;
  64   hh = b % 24;
  65
  66   Time->Hour        = hh;
  67   Time->Minute      = mm;
  68   Time->Second      = ss;
  69   Time->Nanosecond  = 0;
  70
  71 }
  72
  73 /**
  74   Calculate Epoch days
  75  **/
  76 UINTN
  77 EFIAPI
  78 EfiGetEpochDays (
  79   IN  EFI_TIME  *Time
  80   )
  81 {
  82   UINTN a;
  83   UINTN y;
  84   UINTN m;
  85   UINTN JulianDate;  // Absolute Julian Date representation of the supplied Time
  86   UINTN EpochDays;   // Number of days elapsed since EPOCH_JULIAN_DAY
  87
  88   a = (14 - Time->Month) / 12 ;
  89   y = Time->Year + 4800 - a;
  90   m = Time->Month + (12*a) - 3;
  91
  92   JulianDate = Time->Day + ((153*m + 2)/5) + (365*y) + (y/4) - (y/100) + (y/400) - 32045;
  93
  94   ASSERT (JulianDate >= EPOCH_JULIAN_DATE);
  95   EpochDays = JulianDate - EPOCH_JULIAN_DATE;
  96
  97   return EpochDays;
  98 }
  99 /**
 100   Converts EFI_TIME to Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC)
 101  **/
 102 UINTN
 103 EFIAPI
 104 EfiTimeToEpoch (
 105   IN  EFI_TIME  *Time
 106   )
 107 {
 108   UINTN EpochDays;   // Number of days elapsed since EPOCH_JULIAN_DAY
 109   UINTN EpochSeconds;
 110
 111   EpochDays = EfiGetEpochDays (Time);
 112
 113   EpochSeconds = (EpochDays * SEC_PER_DAY) + ((UINTN)Time->Hour * SEC_PER_HOUR) + (Time->Minute * SEC_PER_MIN) + Time->Second;
 114
 115   return EpochSeconds;
 116 }
 117
 118 /**
 119   returns Day of the week [0-6] 0=Sunday
 120  **/
 121 UINTN
 122 EfiTimeToWday (
 123   IN  EFI_TIME  *Time
 124   )
 125 {
 126   UINTN EpochDays;   // Number of days elapsed since EPOCH_JULIAN_DAY
 127
 128   EpochDays = EfiGetEpochDays (Time);
 129
 130   // 4=1/1/1970 was a Thursday
 131
 132   return (EpochDays + 4) % 7;
 133 }
 134
 135 BOOLEAN
 136 EFIAPI
 137 IsLeapYear (
 138   IN EFI_TIME   *Time
 139   )
 140 {
 141   if (Time->Year % 4 == 0) {
 142     if (Time->Year % 100 == 0) {
 143       if (Time->Year % 400 == 0) {
 144         return TRUE;
 145       } else {
 146         return FALSE;
 147       }
 148     } else {
 149       return TRUE;
 150     }
 151   } else {
 152     return FALSE;
 153   }
 154 }
 155
 156 BOOLEAN
 157 EFIAPI
 158 IsDayValid (
 159   IN  EFI_TIME  *Time
 160   )
 161 {
 162   STATIC CONST INTN DayOfMonth[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
 163
 164   if (Time->Day < 1 ||
 165       Time->Day > DayOfMonth[Time->Month - 1] ||
 166       (Time->Month == 2 && (!IsLeapYear (Time) && Time->Day > 28))
 167      ) {
 168     return FALSE;
 169   }
 170
 171   return TRUE;
 172 }
 173
 174 BOOLEAN
 175 EFIAPI
 176 IsTimeValid(
 177   IN EFI_TIME *Time
 178   )
 179 {
 180   // Check the input parameters are within the range specified by UEFI
 181   if ((Time->Year   < 2000) ||
 182      (Time->Year   > 2099) ||
 183      (Time->Month  < 1   ) ||
 184      (Time->Month  > 12  ) ||
 185      (!IsDayValid (Time)    ) ||
 186      (Time->Hour   > 23  ) ||
 187      (Time->Minute > 59  ) ||
 188      (Time->Second > 59  ) ||
 189      (Time->Nanosecond > 999999999) ||
 190      (!((Time->TimeZone == EFI_UNSPECIFIED_TIMEZONE) || ((Time->TimeZone >= -1440) && (Time->TimeZone <= 1440)))) ||
 191      (Time->Daylight & (~(EFI_TIME_ADJUST_DAYLIGHT | EFI_TIME_IN_DAYLIGHT)))
 192   ) {
 193     return FALSE;
 194   }
 195
 196   return TRUE;
 197 }