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//==========================================================================

//

//      hal_misc.c

//

//      HAL miscellaneous functions

//

//==========================================================================

//####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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//

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// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

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//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    nickg

// Contributors: nickg, jlarmour

// Date:         1999-01-21

// Purpose:      HAL miscellaneous functions

// Description:  This file contains miscellaneous functions provided by the

//               HAL.

//

//####DESCRIPTIONEND####

//

//========================================================================*/

#include <pkgconf/hal.h>

#include <cyg/infra/cyg_type.h>         // Base types

#include <cyg/infra/cyg_trac.h>         // tracing macros

#include <cyg/infra/cyg_ass.h>          // assertion macros

#define CYGARC_HAL_COMMON_EXPORT_CPU_MACROS

#include <cyg/hal/hal_arch.h>           // architectural definitions

#include <cyg/hal/hal_intr.h>           // Interrupt handling

#include <cyg/hal/hal_if.h>             // hal_ctrlc_isr()

#include CYGHWR_MEMORY_LAYOUT_H

/*------------------------------------------------------------------------*/

/* If required, define a variable to store the clock period.              */

#ifdef CYGHWR_HAL_CLOCK_PERIOD_DEFINED

CYG_WORD32 cyg_hal_clock_period;

#endif

/*------------------------------------------------------------------------*/

/* First level C exception handler.                                       */

externC void __handle_exception (void);

externC HAL_SavedRegisters *_hal_registers;

externC void* volatile __mem_fault_handler;

externC cyg_uint8 cyg_hal_mips_process_fpe( HAL_SavedRegisters *regs );

externC cyg_uint32 cyg_hal_exception_handler(HAL_SavedRegisters *regs)

{

#if defined(CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS)

    // If we caught an exception inside the stubs, see if we were expecting it

    // and if so jump to the saved address

    if (__mem_fault_handler) {

        regs->pc = (CYG_HAL_OPENRISC_REG)(signed long)__mem_fault_handler;

        return 0; // Caught an exception inside stubs        

    }

    // Set the pointer to the registers of the current exception

    // context. At entry the GDB stub will expand the

    // HAL_SavedRegisters structure into a (bigger) register array.

    _hal_registers = regs;

    __handle_exception();

#elif defined(CYGFUN_HAL_COMMON_KERNEL_SUPPORT) && defined(CYGPKG_HAL_EXCEPTIONS)

    // We should decode the vector and pass a more appropriate

    // value as the second argument. For now we simply pass a

    // pointer to the saved registers. We should also divert

    // breakpoint and other debug vectors into the debug stubs.

    cyg_hal_deliver_exception( regs->vector, (CYG_ADDRWORD)regs );

#else

    CYG_FAIL("Exception!!!");

#endif    

    return 0;

}

/*------------------------------------------------------------------------*/

/* default ISR                                                            */

externC cyg_uint32

hal_arch_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)

{

    return 0;

}

/*------------------------------------------------------------------------*/

// Come here if interrupt triggered, but no apparent cause

void hal_spurious_IRQ(HAL_SavedRegisters *regs) CYGBLD_ATTRIB_WEAK;

void

hal_spurious_IRQ(HAL_SavedRegisters *regs)

{

#if defined(CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS)

    cyg_hal_exception_handler(regs);

#else

    CYG_FAIL("Spurious interrupt!!");

#endif    

}

/*------------------------------------------------------------------------*/

#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG

cyg_bool cyg_hal_stop_constructors;

#endif

typedef void (*pfunc) (void);

extern pfunc __CTOR_LIST__[];

extern pfunc __CTOR_END__[];

void

cyg_hal_invoke_constructors(void)

{

#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG

    static pfunc *p = &__CTOR_END__[-1];

    cyg_hal_stop_constructors = 0;

    for (; p >= __CTOR_LIST__; p--) {

        (*p) ();

        if (cyg_hal_stop_constructors) {

            p--;

            break;

        }

    }

#else

    pfunc *p;

    for (p = &__CTOR_END__[-1]; p >= __CTOR_LIST__; p--)

        (*p) ();

#endif

} // cyg_hal_invoke_constructors()

/*------------------------------------------------------------------------*/

/* Determine the index of the ls bit of the supplied mask.                */

cyg_uint32 hal_lsbit_index(cyg_uint32 mask)

{

    cyg_uint32 n = mask;

    static const signed char tab[64] =

    { -1, 0, 1, 12, 2, 6, 0, 13, 3, 0, 7, 0, 0, 0, 0, 14, 10,

      4, 0, 0, 8, 0, 0, 25, 0, 0, 0, 0, 0, 21, 27 , 15, 31, 11,

      5, 0, 0, 0, 0, 0, 9, 0, 0, 24, 0, 0 , 20, 26, 30, 0, 0, 0,

      0, 23, 0, 19, 29, 0, 22, 18, 28, 17, 16, 0

    };

    n &= ~(n-1UL);

    n = (n<<16)-n;

    n = (n<<6)+n;

    n = (n<<4)+n;

    return tab[n>>26];

}

/*------------------------------------------------------------------------*/

/* Determine the index of the ms bit of the supplied mask.                */

cyg_uint32 hal_msbit_index(cyg_uint32 mask)

{

    cyg_uint32 x = mask;

    cyg_uint32 w;

    /* Phase 1: make word with all ones from that one to the right */

    x |= x >> 16;

    x |= x >> 8;

    x |= x >> 4;

    x |= x >> 2;

    x |= x >> 1;

    /* Phase 2: calculate number of "1" bits in the word        */

    w = (x & 0x55555555) + ((x >> 1) & 0x55555555);

    w = (w & 0x33333333) + ((w >> 2) & 0x33333333);

    w = w + (w >> 4);

    w = (w & 0x000F000F) + ((w >> 8) & 0x000F000F);

    return (cyg_uint32)((w + (w >> 16)) & 0xFF) - 1;

}

/*------------------------------------------------------------------------*/

/* Delay for some number of useconds.                                     */

void

hal_delay_us(int us)

{

    cyg_uint32 val1, val2;

    int diff;

    long usticks;

    long ticks;

    // Calculate the number of counter register ticks per microsecond.

    usticks = (CYGNUM_HAL_RTC_PERIOD * CYGNUM_HAL_RTC_DENOMINATOR) / 1000000;

    // Make sure that the value is not zero.

    if( usticks == 0 ) usticks = 1;

    while( us > 0 )

    {

        int us1 = us;

        // Wait in bursts of less than 10000us to avoid any overflow

        // problems in the multiply.

        if( us1 > 10000 )

            us1 = 10000;

        us -= us1;

        ticks = us1 * usticks;

        HAL_CLOCK_READ(&val1);

        while (ticks > 0) {

            do {

                HAL_CLOCK_READ(&val2);

            } while (val1 == val2);

            diff = val2 - val1;

            if (diff < 0) diff += CYGNUM_HAL_RTC_PERIOD;

            ticks -= diff;

            val1 = val2;

        }

    }

}

/*------------------------------------------------------------------------*/

void hal_arch_program_new_stack(void *_func)

{

    externC void hal_program_new_stack( void *func, CYG_ADDRESS addr);

    hal_program_new_stack( (void *)_func,

                   (CYGMEM_REGION_ram + CYGMEM_REGION_ram_SIZE - sizeof(CYG_ADDRESS)) & ~7 );

}

/*------------------------------------------------------------------------*/

/* Idle thread action                                                     */

#include <cyg/infra/diag.h>

void hal_idle_thread_action( cyg_uint32 count )

{

}

/*------------------------------------------------------------------------*/

/* End of hal_misc.c                                                      */