ArmPlatformPkg/ArmVirtualizationPkg/Library/XenRealTimeClockLib/XenRealTimeClockLib.c

   1 /** @file
   2   Implement EFI RealTimeClock runtime services via Xen shared info page
   3
   4   Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <Uefi.h>
  17 #include <PiDxe.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/DebugLib.h>
  20
  21 /**
  22   Converts Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC) to EFI_TIME
  23  **/
  24 STATIC
  25 VOID
  26 EpochToEfiTime (
  27   IN  UINTN     EpochSeconds,
  28   OUT EFI_TIME  *Time
  29   )
  30 {
  31   UINTN         a;
  32   UINTN         b;
  33   UINTN         c;
  34   UINTN         d;
  35   UINTN         g;
  36   UINTN         j;
  37   UINTN         m;
  38   UINTN         y;
  39   UINTN         da;
  40   UINTN         db;
  41   UINTN         dc;
  42   UINTN         dg;
  43   UINTN         hh;
  44   UINTN         mm;
  45   UINTN         ss;
  46   UINTN         J;
  47
  48   J  = (EpochSeconds / 86400) + 2440588;
  49   j  = J + 32044;
  50   g  = j / 146097;
  51   dg = j % 146097;
  52   c  = (((dg / 36524) + 1) * 3) / 4;
  53   dc = dg - (c * 36524);
  54   b  = dc / 1461;
  55   db = dc % 1461;
  56   a  = (((db / 365) + 1) * 3) / 4;
  57   da = db - (a * 365);
  58   y  = (g * 400) + (c * 100) + (b * 4) + a;
  59   m  = (((da * 5) + 308) / 153) - 2;
  60   d  = da - (((m + 4) * 153) / 5) + 122;
  61
  62   Time->Year  = y - 4800 + ((m + 2) / 12);
  63   Time->Month = ((m + 2) % 12) + 1;
  64   Time->Day   = d + 1;
  65
  66   ss = EpochSeconds % 60;
  67   a  = (EpochSeconds - ss) / 60;
  68   mm = a % 60;
  69   b = (a - mm) / 60;
  70   hh = b % 24;
  71
  72   Time->Hour        = hh;
  73   Time->Minute      = mm;
  74   Time->Second      = ss;
  75   Time->Nanosecond  = 0;
  76
  77 }
  78
  79 /**
  80   Returns the current time and date information, and the time-keeping capabilities
  81   of the hardware platform.
  82
  83   @param  Time                  A pointer to storage to receive a snapshot of the current time.
  84   @param  Capabilities          An optional pointer to a buffer to receive the real time clock
  85                                 device's capabilities.
  86
  87   @retval EFI_SUCCESS           The operation completed successfully.
  88   @retval EFI_INVALID_PARAMETER Time is NULL.
  89   @retval EFI_DEVICE_ERROR      The time could not be retrieved due to hardware error.
  90
  91 **/
  92 EFI_STATUS
  93 EFIAPI
  94 LibGetTime (
  95   OUT EFI_TIME                *Time,
  96   OUT  EFI_TIME_CAPABILITIES  *Capabilities
  97   )
  98 {
  99   ASSERT (Time != NULL);
 100
 101   //
 102   // For now, there is nothing that we can do besides returning a bogus time,
 103   // as Xen's timekeeping uses a shared info page which cannot be shared
 104   // between UEFI and the OS
 105   //
 106   EpochToEfiTime(1421770011, Time);
 107
 108   return EFI_SUCCESS;
 109 }
 110
 111 /**
 112   Sets the current local time and date information.
 113
 114   @param  Time                  A pointer to the current time.
 115
 116   @retval EFI_SUCCESS           The operation completed successfully.
 117   @retval EFI_INVALID_PARAMETER A time field is out of range.
 118   @retval EFI_DEVICE_ERROR      The time could not be set due due to hardware error.
 119
 120 **/
 121 EFI_STATUS
 122 EFIAPI
 123 LibSetTime (
 124   IN EFI_TIME                *Time
 125   )
 126 {
 127   return EFI_DEVICE_ERROR;
 128 }
 129
 130
 131 /**
 132   Returns the current wakeup alarm clock setting.
 133
 134   @param  Enabled               Indicates if the alarm is currently enabled or disabled.
 135   @param  Pending               Indicates if the alarm signal is pending and requires acknowledgement.
 136   @param  Time                  The current alarm setting.
 137
 138   @retval EFI_SUCCESS           The alarm settings were returned.
 139   @retval EFI_INVALID_PARAMETER Any parameter is NULL.
 140   @retval EFI_DEVICE_ERROR      The wakeup time could not be retrieved due to a hardware error.
 141   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.
 142
 143 **/
 144 EFI_STATUS
 145 EFIAPI
 146 LibGetWakeupTime (
 147   OUT BOOLEAN     *Enabled,
 148   OUT BOOLEAN     *Pending,
 149   OUT EFI_TIME    *Time
 150   )
 151 {
 152   return EFI_UNSUPPORTED;
 153 }
 154
 155 /**
 156   Sets the system wakeup alarm clock time.
 157
 158   @param  Enabled               Enable or disable the wakeup alarm.
 159   @param  Time                  If Enable is TRUE, the time to set the wakeup alarm for.
 160
 161   @retval EFI_SUCCESS           If Enable is TRUE, then the wakeup alarm was enabled. If
 162                                 Enable is FALSE, then the wakeup alarm was disabled.
 163   @retval EFI_INVALID_PARAMETER A time field is out of range.
 164   @retval EFI_DEVICE_ERROR      The wakeup time could not be set due to a hardware error.
 165   @retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.
 166
 167 **/
 168 EFI_STATUS
 169 EFIAPI
 170 LibSetWakeupTime (
 171   IN BOOLEAN      Enabled,
 172   OUT EFI_TIME    *Time
 173   )
 174 {
 175   return EFI_UNSUPPORTED;
 176 }
 177
 178 /**
 179   This is the declaration of an EFI image entry point. This can be the entry point to an application
 180   written to this specification, an EFI boot service driver, or an EFI runtime driver.
 181
 182   @param  ImageHandle           Handle that identifies the loaded image.
 183   @param  SystemTable           System Table for this image.
 184
 185   @retval EFI_SUCCESS           The operation completed successfully.
 186
 187 **/
 188 EFI_STATUS
 189 EFIAPI
 190 LibRtcInitialize (
 191   IN EFI_HANDLE                            ImageHandle,
 192   IN EFI_SYSTEM_TABLE                      *SystemTable
 193   )
 194 {
 195   return EFI_SUCCESS;
 196 }