emulate.cxx

eCos/RedBoot for勤研ARM AnywhereII(4510) 含全部源代码

//==========================================================================
//
//      io/wallclock/emulate.cxx
//
//      Wallclock emulation implementation
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
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//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     nickg
// Contributors:  nickg
// Date:          1999-03-05
// Purpose:       Wallclock emulation
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <pkgconf/wallclock.h>          // Wallclock device config
#include <pkgconf/kernel.h>             // Kernel config

#include <cyg/infra/cyg_type.h>         // Common type definitions and support
#include <cyg/kernel/ktypes.h>

#include <cyg/io/wallclock.hxx>         // The WallClock API

#include <cyg/kernel/clock.hxx>         // Access to kernel clock
#include <cyg/kernel/clock.inl>


// Remember the tick count at the time of initialization.
static cyg_tick_count epoch_ticks;

//-----------------------------------------------------------------------------
// Called to initialize the hardware clock with a known valid
// time. Which of course isn't required when doing emulation using the
// kernel clock. But we set the private epoch base to "now".
void
Cyg_WallClock::init_hw_seconds( void )
{
    // Remember the current clock tick count.
    epoch_ticks = Cyg_Clock::real_time_clock->current_value();
}

//-----------------------------------------------------------------------------
// Returns the number of seconds elapsed since the init call.
cyg_uint32 
Cyg_WallClock::get_hw_seconds( void )
{
    Cyg_Clock::cyg_resolution res = 
        Cyg_Clock::real_time_clock->get_resolution();
    cyg_tick_count secs = Cyg_Clock::real_time_clock->current_value()
        - epoch_ticks;

    secs = secs / ( ( res.divisor * 1000000000LL ) / res.dividend );

    return secs;
}

//-----------------------------------------------------------------------------
// End of devs/wallclock/emulate.cxx