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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, 2007 Free Software Foundation, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under    

// the terms of the GNU General Public License as published by the Free     

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// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    

// for more details.                                                        

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// You should have received a copy of the GNU General Public License        

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//

// As a special exception, if other files instantiate templates or use      

// macros or inline functions from this file, or you compile this file      

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// This exception does not invalidate any other reasons why a work based    

// on this file might be covered by the GNU General Public License.         

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

#include <pkgconf/hal.h>

#include <cyg/infra/cyg_type.h>

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

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

#include <cyg/hal/hal_arch.h>           // HAL header

#include <cyg/hal/hal_intr.h>           // VSR/ISR defines

#include <cyg/hal/hal_misc.h>

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

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

#ifdef CYGHWR_HAL_CLOCK_PERIOD_DEFINED

CYG_WORD32 cyg_hal_clock_period;

#endif

/*****************************************************************************

hal_default_exception_handler -- First level C exception handler

     The assembly default VSR  handler calls  this routine  to handle  the

exception.  When this routine returns, the  state is restored to the  state

pointed to by regs.

     We declare this  routine as  weak so  that other  handlers can  easily

become the default exception handler.

INPUT:

     vector: The exception vector number.

     regs: A pointer to the saved state.

OUTPUT:

RETURN VALUE:

     None

*****************************************************************************/

externC void

hal_default_exception_handler(CYG_WORD vector, HAL_SavedRegisters *regs)

                                                    __attribute__ ((weak));

void hal_default_exception_handler(CYG_WORD vector, HAL_SavedRegisters *regs)

{

#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS

    externC void __handle_exception(void);

    externC HAL_SavedRegisters * _hal_registers;

    // 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(vector, (CYG_ADDRWORD)regs);

#else

    CYG_FAIL("Exception!!!");

#endif

    return;

}

//---------------------------------------------------------------------------

// Default arch ISR

externC cyg_uint32

hal_arch_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)

{

    CYG_FAIL("Spurious Interrupt!!!");

    return 0;

}

//---------------------------------------------------------------------------

// Idle thread action

void

hal_idle_thread_action( cyg_uint32 count )

{

}

//-----------------------------------------------------------------------------

// Monitor initialization. This means to init the vsr vector table.

// TODO maybe init hal_vsr_table through defining it in assembler code

#ifndef CYGPKG_HAL_FR30_MON_DEFINED

void hal_mon_init(void){

    int i;

    /* 0 - 14 exceptions */

    for(i = 0; i < CYGNUM_HAL_VECTOR_INTRFIRST; i++){

        hal_vsr_table[i] = (CYG_ADDRESS)__default_exception_vsr;

    }

    /* 15 - xx interrupts */

    for( ; i < CYGNUM_HAL_VECTOR_INTRLAST; i++){

        hal_vsr_table[i] = (CYG_ADDRESS)__default_interrupt_vsr;

    }

    /*  xx+1 - 255 exceptions (fr30 traps) */

    for( ; i < CYGNUM_HAL_VSR_MAX; i++){

        hal_vsr_table[i] = (CYG_ADDRESS)__default_exception_vsr;

    }

}

#endif

//---------------------------------------------------------------------------

// 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. FIXME: since we

// have hardware support for it, use it! (bit search module)

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);

}

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

/* C++ support - run initial constructors                                 */

#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

}

//---------------------------------------------------------------------------