hal_misc.c

ecos为实时嵌入式操作系统

/*==========================================================================
//
//      hal_misc.c
//
//      HAL miscellaneous functions
//
//==========================================================================
//####COPYRIGHTBEGIN####
//
// -------------------------------------------
// The contents of this file are subject to the Cygnus eCos Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License.  You may obtain a copy of the License at
// http://sourceware.cygnus.com/ecos
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the
// License for the specific language governing rights and limitations under
// the License.
// 
// The Original Code is eCos - Embedded Cygnus Operating System, released
// September 30, 1998.
// 
// The Initial Developer of the Original Code is Cygnus.  Portions created
// by Cygnus are Copyright (C) 1998,1999 Cygnus Solutions.  All Rights Reserved.
// -------------------------------------------
//
//####COPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    nickg
// Contributors: nickg, jlarmour
// Date:         1999-02-18
// 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>

#include <cyg/hal/hal_arch.h>

#include <cyg/hal/hal_intr.h>

#include <cyg/hal/hal_cache.h>

#if 0
void trace( CYG_ADDRWORD tag, CYG_ADDRWORD a1, CYG_ADDRWORD a2)
{
    CYG_ADDRWORD **pp = (CYG_ADDRWORD **)0x48100000;
    CYG_ADDRWORD *ix = (CYG_ADDRWORD *)0x4810000C;
    CYG_ADDRWORD *p = *pp;
    *p++ = tag;
    *ix = *ix + 1;
    *p++ = *ix;
    *p++ = a1;
    *p++ = a2;
    *pp = p;
}
#endif

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

#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
cyg_bool cyg_hal_stop_constructors;
#endif

void
cyg_hal_invoke_constructors(void)
{
    typedef void (*pfunc) (void);
    extern pfunc _CTOR_LIST__[];
    extern pfunc _CTOR_END__[];

#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()

void
cyg_hal_enable_caches(void)
{
#ifdef CYG_HAL_MN10300_STDEVAL1    

    // On the real hardware we also enable the cache.
    // doing this here is a temporary measure until we
    // have a proper platform specific place to do it.
    
    // Note that the hardware seems to come up with the
    // caches containing random data. Hence they must be
    // invalidated before being enabled.
    
    HAL_ICACHE_INVALIDATE_ALL();    
    HAL_ICACHE_ENABLE();
    HAL_DCACHE_INVALIDATE_ALL();
    HAL_DCACHE_ENABLE();

#endif

} // cyg_hal_enable_caches()

void
cyg_hal_debug_init(void)
{
#if defined(CYGPKG_KERNEL)                      && \
    defined(CYGFUN_HAL_COMMON_KERNEL_SUPPORT)   && \
    defined(CYG_HAL_USE_ROM_MONITOR)            && \
    defined(CYG_HAL_USE_ROM_MONITOR_CYGMON)
    {
        extern CYG_ADDRESS hal_virtual_vector_table[32];
        extern void patch_dbg_syscalls(void * vector);
        patch_dbg_syscalls( (void *)(&hal_virtual_vector_table[0]) );
    }
#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.                */

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);

}

/*------------------------------------------------------------------------*/
/* First level C exception handler.                                       */

externC void __handle_exception (void);

externC HAL_SavedRegisters *_hal_registers;

void
cyg_hal_exception_handler(HAL_SavedRegisters *regs)
{
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_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)
    
    CYG_WORD vector = regs->vector;

    if( vector == CYGNUM_HAL_INTERRUPT_WATCHDOG )
    {
        // Special case the watchdog timer exception, look for an
        // ISR for it and call it if present. Otherwise pass on to
        // the exception system.
        
        cyg_uint32 (*isr)(CYG_ADDRWORD,CYG_ADDRWORD);
        cyg_uint32 index;

        HAL_TRANSLATE_VECTOR( CYGNUM_HAL_INTERRUPT_WATCHDOG, index );
        
        isr = (cyg_uint32 (*)(CYG_ADDRWORD,CYG_ADDRWORD))
            (hal_interrupt_handlers[index]);

        if( isr != 0 )
        {
            isr(CYGNUM_HAL_INTERRUPT_WATCHDOG,
                hal_interrupt_data[CYGNUM_HAL_INTERRUPT_WATCHDOG]
                );
            return;
        }
    }

#if 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 );

#endif

#endif
    
    return;
}

/*------------------------------------------------------------------------*/
/* End of hal_misc.c                                                      */