XenRealTimeClockLib.c

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#include <Uefi.h>
#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
 
STATIC
VOID
EpochToEfiTime (
  IN  UINTN     EpochSeconds,
  OUT EFI_TIME  *Time
  )
{
  UINTN  a;
  UINTN  b;
  UINTN  c;
  UINTN  d;
  UINTN  g;
  UINTN  j;
  UINTN  m;
  UINTN  y;
  UINTN  da;
  UINTN  db;
  UINTN  dc;
  UINTN  dg;
  UINTN  hh;
  UINTN  mm;
  UINTN  ss;
  UINTN  J;
 
  J  = (EpochSeconds / 86400) + 2440588;
  j  = J + 32044;
  g  = j / 146097;
  dg = j % 146097;
  c  = (((dg / 36524) + 1) * 3) / 4;
  dc = dg - (c * 36524);
  b  = dc / 1461;
  db = dc % 1461;
  a  = (((db / 365) + 1) * 3) / 4;
  da = db - (a * 365);
  y  = (g * 400) + (c * 100) + (b * 4) + a;
  m  = (((da * 5) + 308) / 153) - 2;
  d  = da - (((m + 4) * 153) / 5) + 122;
 
  Time->Year  = (UINT16)(y - 4800 + ((m + 2) / 12));
  Time->Month = ((m + 2) % 12) + 1;
  Time->Day   = (UINT8)(d + 1);
 
  ss = EpochSeconds % 60;
  a  = (EpochSeconds - ss) / 60;
  mm = a % 60;
  b  = (a - mm) / 60;
  hh = b % 24;
 
  Time->Hour       = (UINT8)hh;
  Time->Minute     = (UINT8)mm;
  Time->Second     = (UINT8)ss;
  Time->Nanosecond = 0;
}
 
EFI_STATUS
EFIAPI
LibGetTime (
  OUT EFI_TIME                *Time,
  OUT  EFI_TIME_CAPABILITIES  *Capabilities
  )
{
  ASSERT (Time != NULL);
 
  //
  // For now, there is nothing that we can do besides returning a bogus time,
  // as Xen's timekeeping uses a shared info page which cannot be shared
  // between UEFI and the OS
  //
  EpochToEfiTime (1421770011, Time);
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
LibSetTime (
  IN EFI_TIME  *Time
  )
{
  return EFI_DEVICE_ERROR;
}
 
EFI_STATUS
EFIAPI
LibGetWakeupTime (
  OUT BOOLEAN   *Enabled,
  OUT BOOLEAN   *Pending,
  OUT EFI_TIME  *Time
  )
{
  return EFI_UNSUPPORTED;
}
 
EFI_STATUS
EFIAPI
LibSetWakeupTime (
  IN BOOLEAN    Enabled,
  OUT EFI_TIME  *Time
  )
{
  return EFI_UNSUPPORTED;
}
 
EFI_STATUS
EFIAPI
LibRtcInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  return EFI_SUCCESS;
}