/*++ @file
  Since the SEC is the only program in our emulation we 
  must use a UEFI/PI mechanism to export APIs to other modules.
  This is the role of the EFI_EMU_THUNK_PROTOCOL.

  The mUnixThunkTable exists so that a change to EFI_EMU_THUNK_PROTOCOL
  will cause an error in initializing the array if all the member functions
  are not added. It looks like adding a element to end and not initializing
  it may cause the table to be initaliized with the members at the end being
  set to zero. This is bad as jumping to zero will crash.

Copyright (c) 2004 - 2009, Intel Corporation. All rights reserved.<BR>
Portions copyright (c) 2008 - 2011, Apple Inc. All rights reserved.<BR>
This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

**/

#include "SecMain.h"

#ifdef __APPLE__
#define DebugAssert _Mangle__DebugAssert

#include <assert.h>
#include <CoreServices/CoreServices.h>
#include <mach/mach.h>
#include <mach/mach_time.h>

#undef DebugAssert
#endif

int settimer_initialized;
struct timeval settimer_timeval;
void (*settimer_callback)(UINT64 delta);

BOOLEAN gEmulatorInterruptEnabled = FALSE;


UINTN
SecWriteStdErr (
  IN UINT8     *Buffer,
  IN UINTN     NumberOfBytes
  )
{
  ssize_t Return;
  
  Return = write (1, (const void *)Buffer, (size_t)NumberOfBytes);
  
  return (Return == -1) ? 0 : Return;
}



void
settimer_handler (int sig)
{
  struct timeval timeval;
  UINT64 delta;

  gettimeofday (&timeval, NULL);
  delta = ((UINT64)timeval.tv_sec * 1000) + (timeval.tv_usec / 1000)
    - ((UINT64)settimer_timeval.tv_sec * 1000) 
    - (settimer_timeval.tv_usec / 1000);
  settimer_timeval = timeval;
  
  if (settimer_callback) {
    ReverseGasketUint64 (settimer_callback, delta);
  }
}

VOID
SecSetTimer (
  IN  UINT64                  PeriodMs,
  IN  EMU_SET_TIMER_CALLBACK  CallBack
  )
{
  struct itimerval timerval;
  UINT32 remainder;

  if (!settimer_initialized) {
    struct sigaction act;

    settimer_initialized = 1;
    act.sa_handler = settimer_handler;
    act.sa_flags = 0;
    sigemptyset (&act.sa_mask);
    gEmulatorInterruptEnabled = TRUE;
    if (sigaction (SIGALRM, &act, NULL) != 0) {
      printf ("SetTimer: sigaction error %s\n", strerror (errno));
    }
    if (gettimeofday (&settimer_timeval, NULL) != 0) {
      printf ("SetTimer: gettimeofday error %s\n", strerror (errno));
    }
  }
  timerval.it_value.tv_sec = DivU64x32(PeriodMs, 1000);
  DivU64x32Remainder(PeriodMs, 1000, &remainder);
  timerval.it_value.tv_usec = remainder * 1000;
  timerval.it_value.tv_sec = DivU64x32(PeriodMs, 1000);
  timerval.it_interval = timerval.it_value;
  
  if (setitimer (ITIMER_REAL, &timerval, NULL) != 0) {
    printf ("SetTimer: setitimer error %s\n", strerror (errno));
  }
  settimer_callback = CallBack;
}


VOID
SecEnableInterrupt (
  VOID
  )
{
  sigset_t  sigset;

  gEmulatorInterruptEnabled = TRUE;
  // Since SetTimer() uses SIGALRM we emulate turning on and off interrupts 
  // by enabling/disabling SIGALRM.
  sigemptyset (&sigset);
  sigaddset (&sigset, SIGALRM);
  pthread_sigmask (SIG_UNBLOCK, &sigset, NULL);
}


VOID
SecDisableInterrupt (
  VOID
  )
{
  sigset_t  sigset;

  // Since SetTimer() uses SIGALRM we emulate turning on and off interrupts 
  // by enabling/disabling SIGALRM.
  sigemptyset (&sigset);
  sigaddset (&sigset, SIGALRM);
  pthread_sigmask (SIG_BLOCK, &sigset, NULL);
  gEmulatorInterruptEnabled = FALSE;
}


BOOLEAN
SecInterruptEanbled (void)
{
  return gEmulatorInterruptEnabled;
}


UINT64
QueryPerformanceFrequency (
  VOID
  )
{
  // Hard code to nanoseconds
  return 1000000000ULL;
}

UINT64
QueryPerformanceCounter (
  VOID
  )
{
#if __APPLE__
  UINT64          Start;
  Nanoseconds     elapsedNano;

  Start = mach_absolute_time ();
  
  // Convert to nanoseconds.

  // Have to do some pointer fun because AbsoluteToNanoseconds 
  // works in terms of UnsignedWide, which is a structure rather 
    // than a proper 64-bit integer.
  elapsedNano = AbsoluteToNanoseconds (*(AbsoluteTime *) &Start);

  return *(uint64_t *) &elapsedNano;
#else
  // Need to figure out what to do for Linux?
  return 0;
#endif
}
  


VOID
SecSleep (
  IN  UINT64 Milliseconds
  )
{
  struct timespec rq, rm;
  struct timeval  start, end;
  unsigned long  MicroSec;
  
  rq.tv_sec = Milliseconds / 1000;
  rq.tv_nsec = (Milliseconds % 1000) * 1000000;

  //
  // nanosleep gets interrupted by our timer tic. 
  // we need to track wall clock time or we will stall for way too long
  //
  gettimeofday (&start, NULL);
  end.tv_sec  = start.tv_sec + rq.tv_sec;
  MicroSec = (start.tv_usec + rq.tv_nsec/1000);
  end.tv_usec = MicroSec % 1000000;
  if (MicroSec > 1000000) {
    end.tv_sec++;
  }

  while (nanosleep (&rq, &rm) == -1) {
    if (errno != EINTR) {
      break;
    }
    gettimeofday (&start, NULL);
    if (start.tv_sec > end.tv_sec) {
      break;
    } if ((start.tv_sec == end.tv_sec) && (start.tv_usec > end.tv_usec)) {
      break;
    }
    rq = rm;
  } 
}

VOID
SecExit (
  UINTN   Status
  )
{
  exit (Status);
}


VOID
SecGetTime (
  OUT  EFI_TIME               *Time,
  OUT EFI_TIME_CAPABILITIES   *Capabilities OPTIONAL
  )
{
  struct tm *tm;
  time_t t;

  t = time (NULL);
  tm = localtime (&t);

  Time->Year = 1900 + tm->tm_year;
  Time->Month = tm->tm_mon + 1;
  Time->Day = tm->tm_mday;
  Time->Hour = tm->tm_hour;
  Time->Minute = tm->tm_min;
  Time->Second = tm->tm_sec;
  Time->Nanosecond = 0;
  Time->TimeZone = timezone;
  Time->Daylight = (daylight ? EFI_TIME_ADJUST_DAYLIGHT : 0)
    | (tm->tm_isdst > 0 ? EFI_TIME_IN_DAYLIGHT : 0);
    
  if (Capabilities != NULL) {
    Capabilities->Resolution  = 1;
    Capabilities->Accuracy    = 50000000;
    Capabilities->SetsToZero  = FALSE;
  }
}



VOID
SecSetTime (
  IN  EFI_TIME               *Time
  )
{
  // Don't change the time on the system
  // We could save delta to localtime() and have SecGetTime adjust return values?
  return;
}


EFI_STATUS
SecGetNextProtocol (
  IN  BOOLEAN                 EmuBusDriver,
  OUT EMU_IO_THUNK_PROTOCOL   **Instance   OPTIONAL
  )
{
  return GetNextThunkProtocol (EmuBusDriver, Instance);
}


EMU_THUNK_PROTOCOL gEmuThunkProtocol = {
  GasketSecWriteStdErr,
  GasketSecPeCoffGetEntryPoint,
  GasketSecPeCoffRelocateImageExtraAction,
  GasketSecPeCoffUnloadImageExtraAction,
  GasketSecEnableInterrupt,
  GasketSecDisableInterrupt,
  GasketQueryPerformanceFrequency,
  GasketQueryPerformanceCounter,
  GasketSecSleep,
  GasketSecExit,
  GasketSecGetTime,                
  GasketSecSetTime,
  GasketSecSetTimer,  
  GasketSecGetNextProtocol
};


VOID
SecInitThunkProtocol (
  VOID
  )
{
  // timezone and daylight lib globals depend on tzset be called 1st.
  tzset ();
}