hal_misc.c

ecos移植到R8H系列的源码。源码包来自http://www.cetoni.de/develop/develop_ecosh8s_en.html

//==========================================================================
//
//      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.
//
// 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
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// 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
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####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####
//
//==========================================================================


//==========================================================================
//                            DOXYGEN FILE HEADER
/// \file    hal_misc.c
/// \brief   HAL miscellaneous functions
/// \author  nickg, jlarmour
/// \date    1999-02-18
///
/// This file contains miscellaneous functions provided by the HAL.
//==========================================================================


//==========================================================================
//                                INCLUDES
//==========================================================================
#include <pkgconf/hal.h>

#include <cyg/infra/cyg_type.h>
#include <cyg/infra/cyg_trac.h>
#include <cyg/infra/cyg_ass.h>
#include <cyg/infra/diag.h>

#include <cyg/hal/hal_arch.h>
#include <cyg/hal/hal_intr.h>


//--------------------------------------------------------------------------
// This option supports environments where some constructors must be run 
// in the context of a thread rather than at simple system startup time.  
//
#ifdef CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
///
/// Set to 1 when constructors should no longer be invoked.
/// It is up to some other package to deal with the rest of the constructors. 
/// In the current version this is only possible with the C library.
///
cyg_bool cyg_hal_stop_constructors;
#endif


//==========================================================================
//                   CALL CONSTRUCTORS FOR STATIC OBJECTS
///
///  This calls static constructors before program start.
///  This calls the constructors for all static objects before the program
///  starts. eCos relies on these being called in the correct order for 
///  it to function correctly. The exact way in which constructors are 
///  handled may differ between architectures, although most use a simple 
///  table of function pointers between labels __CTOR_LIST__ and 
///  __CTOR_END__ which must called in order from the top down. 
///  Generally, this function can be copied directly from an existing 
///  architecture HAL.
//==========================================================================
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()


//==========================================================================
//                        INDEX OF LS BIT IN MASK
///
///  Determine the index of the ls bit of the supplied mask. 
///  Because the H8S does not support these by hardware we have to implement
///  the macro HAL_LSBIT_INDEX( index, mask ) as call to this function.
///  This function is copied from h8300 HAL from yshinori sato.
///
///  \param mask  Bit mask to be processed
///
///  \return  Index of ls bit in mask
//==========================================================================
cyg_uint32 hal_lsbit_index(cyg_uint32 mask)
{
    int bit = -1;
    
    if (mask == 0)
	return -1;

    if ((mask & 0xffff) == 0) {
	mask >>= 16;
	bit += 16;
    }
    if ((mask & 0xff) == 0) {
	mask >>= 8;
	bit += 8;
    }

    __asm__("1:\n\t"
	    "adds #1,%0\n\t"
	    "shlr.b %w2\n\t"
	    "bcc 1b\n\t"
	    :"=r"(bit):"0"(bit),"r"(mask));

    return bit;
}


//==========================================================================
//                        INDEX OF LS BIT IN MASK
///
///  Determine the index of the ms bit of the supplied mask. 
///  Because the H8S does not support these by hardware we have to implement
///  the macro HAL_MSBIT_INDEX( index, mask ) as call to this function.
///  This function is copied from h8300 HAL from yshinori sato.
///
///  \param mask   Bit mask to be processed.
///
///  \return  Index of ms bit in supplied mask
//==========================================================================
cyg_uint32 hal_msbit_index(cyg_uint32 mask)
{
    unsigned int bit = 8;
    
    if (mask == 0)
	return -1;

    if ((mask & ~0xffff) != 0)
	mask >>= 16;
    else
	bit += 16;

    if ((mask & 0xff00) != 0)
	mask >>= 8;
    else
	bit += 8;

    __asm__("1:\n\t"
	    "dec.b %w0\n\t"
	    "shll.b %w2\n\t"
	    "bcc 1b\n\t"
	    :"=r"(bit):"0"(bit),"r"(mask));

    return bit;
}


//==========================================================================
//                       DEFAULT ARCHITECTURE ISR
///
///  Default architecture interrupt service routine.
///  The real default ISR, hal_default_isr, is in 
///  hal/common/.../src/hal_misc.c and calls this architecture ISR. 
///  Normally this function should just return
///
///  \param   vector  Interrupt vector
///  \param   data    Points to some interrupt data
///
///  \return  Zero
//==========================================================================
externC cyg_uint32 hal_arch_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
    CYG_FAIL("Spurious interrupt!");
    return 0;
}



externC void __handle_exception (void);       ///< GDB exception handler
externC HAL_SavedRegisters *_hal_registers;   ///< saved machine state for GDB
//==========================================================================
//                       FIRST LEVEL C EXCEPTION HANDLER
///
///  First level C exception handler.
///  This function is called from the exception VSR. It usually does
///  extra decoding of the exception and invokes any special handlers 
///  for things like FPU traps, bus errors or memory exceptions. If there 
///  is nothing special to be done for an exception, then it either
///  calls into the GDB stubs, by calling __handle_exception(), or 
///  invokes the kernel by calling cyg_hal_deliver_exception()
///
///  \param regs    Points to saved machine stack on stack
///  \param vector  Exception vector
//==========================================================================
void cyg_hal_exception_handler(HAL_SavedRegisters *regs, CYG_WORD vector)
{
//
// if GDB is included then we let GDB handle the exception
//
#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) && 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
}


//==========================================================================
//                          IDLE THREAD ACTION
///
///    Idle thread action called from idle thread.
///    This function is called from the idle thread via the
///    HAL_IDLE_THREAD_ACTION() macro, if so defined. While normally this 
///    function does nothing, during development this is often a good place 
///    to report various important system parameters on LCDs, LED or other 
///    displays. This function can also monitor system state and report any 
///    anomalies. If the architecture supports a halt instruction then this 
///    is a good place to put an inline assembly fragment to execute it. 
///    It is also a good place to handle any power saving activity.
///
///    \param loop_count  Counter provided by idle thread - counts how 
///                       often idle thread was executed.
//==========================================================================
externC void hal_idle_thread_action(cyg_uint32 loop_count)
{
}


//==========================================================================
//                                MANUAL RESET
///
///  Resets board by jumping to manual reset vector.
///  This istruction will bring us to the to the address stored in
///  the exception vector MANUAL RESET of the hardware vector table.
///  This will bring us to _start.
///
///  \note 
///     Normally this should be the same for the whole H8S architecture.
///     But you can overwrite it in variant or platform part by defining
///     CYGPKG_HAL_H8S_MRESET_DEFINED
//==========================================================================
#ifndef CYGPKG_HAL_H8S_MRESET_DEFINED
void h8s_reset_manual(void)
{
    __asm__ ("jmp @@4\n\t");
}
#endif

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