hal_misc.c

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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.
//
// 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:         1999-01-21
// 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_cache.h>          // Cache handling
#include <cyg/hal/hal_if.h>             // hal_ctrlc_isr()
#include <cyg/hal/mips-regs.h>          // FPU cause register definitions

#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(CYGHWR_HAL_MIPS_FPU) || \
    (defined(CYGFUN_HAL_COMMON_KERNEL_SUPPORT) && defined(CYGPKG_HAL_EXCEPTIONS))
    int vec = regs->vector>>2;
#endif

#if defined(CYGHWR_HAL_MIPS_FPU)
    // Special handling of FPU exceptions
    if (CYGNUM_HAL_VECTOR_FPE == vec) {

#if defined(CYGSEM_HAL_MIPS_EMULATE_UNIMPLEMENTED_FPU_OPS)
        // We may be required to emulate certain unimplemented Floating Point
        // operations

        // cyg_hal_mips_process_fpe() returns non-zero if it could handle
        // the exception successfully. If so, we just return

        if ( cyg_hal_mips_process_fpe(regs) )
            return 0;
#endif

        // Find the cause of the FPU exception, clear the flag and use
        // the decoded vector number.
        {
            cyg_uint32 cause = regs->fcr31;

            if (cause & FCR31_CAUSE_I) {
                vec = CYGNUM_HAL_EXCEPTION_FPU_INEXACT;
                cause &= ~(FCR31_FLAGS_I | FCR31_CAUSE_I);
            } else if (cause & FCR31_CAUSE_U) {
                vec = CYGNUM_HAL_EXCEPTION_FPU_UNDERFLOW;
                cause &= ~(FCR31_FLAGS_U | FCR31_CAUSE_U);
            } else if (cause & FCR31_CAUSE_O) {
                vec = CYGNUM_HAL_EXCEPTION_FPU_OVERFLOW;
                cause &= ~(FCR31_FLAGS_O | FCR31_CAUSE_O);
            } else if (cause & FCR31_CAUSE_Z) {
                vec = CYGNUM_HAL_EXCEPTION_FPU_DIV_BY_ZERO;
                cause &= ~(FCR31_FLAGS_Z | FCR31_CAUSE_Z);
            } else if (cause & FCR31_CAUSE_V) {
                vec = CYGNUM_HAL_EXCEPTION_FPU_INVALID;
                cause &= ~(FCR31_FLAGS_V | FCR31_CAUSE_V);
            }
            regs->fcr31 = cause;

#if 1
            // Update the FPU status register with the new
            // setting. This is a workaround for the signal2 test
            // which does a longjump in the exception handler and thus
            // never gets around to executing the register restore
            // code.
            asm ("ctc1	%0,$31" : : "r" (cause));
#endif
        }
    }
#endif // CYGHWR_HAL_MIPS_FPU


#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_MIPS_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( vec, (CYG_ADDRWORD)regs );

#else
    
    CYG_FAIL("Exception!!!");
    
#endif    
    return 0;
}

/*------------------------------------------------------------------------*/
/* default ISR                                                            */

#ifndef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT
externC cyg_uint32 hal_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
#if defined(CYGDBG_HAL_MIPS_DEBUG_GDB_CTRLC_SUPPORT) &&      \
    defined(CYGHWR_HAL_GDB_PORT_VECTOR) &&              \
    defined(HAL_CTRLC_ISR)

#ifndef CYGIMP_HAL_COMMON_INTERRUPTS_CHAIN    
    if( vector == CYGHWR_HAL_GDB_PORT_VECTOR )
#endif        
    {
        cyg_uint32 result = HAL_CTRLC_ISR( vector, data );
        if( result != 0 ) return result;
    }
    
#if defined(CYGSEM_HAL_USE_ROM_MONITOR_CygMon)
#if defined(HAL_DIAG_IRQ_CHECK)
    {
        cyg_uint32 ret;
        /* let ROM monitor handle unexpected interrupts */
        HAL_DIAG_IRQ_CHECK(vector, ret);
        if (ret<=0)
            return ret;
    }
#endif // def HAL_DIAG_IRQ_CHECK
#endif // def CYGSEM_HAL_USE_ROM_MONITOR_CygMon
#endif
    
    CYG_TRACE1(true, "Interrupt: %d", vector);
    CYG_FAIL("Spurious Interrupt!!!");
    return 0;
}

#else // CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

externC cyg_uint32 hal_arch_default_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
#if defined(CYGDBG_HAL_MIPS_DEBUG_GDB_CTRLC_SUPPORT) &&      \
    defined(CYGHWR_HAL_GDB_PORT_VECTOR) &&              \
    defined(HAL_CTRLC_ISR)

#if defined(CYGSEM_HAL_USE_ROM_MONITOR_CygMon)
#if defined(HAL_DIAG_IRQ_CHECK)
    {
        cyg_uint32 ret;
        /* let ROM monitor handle unexpected interrupts */
        HAL_DIAG_IRQ_CHECK(vector, ret);
        if (ret<=0)
            return ret;
    }
#endif // def HAL_DIAG_IRQ_CHECK
#endif // def CYGSEM_HAL_USE_ROM_MONITOR_CygMon
#endif

#ifdef CYGPKG_REDBOOT
    hal_ctrlc_isr( vector, data );
#endif    
    
    return 0;
}

#endif // CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

/*------------------------------------------------------------------------*/
/* data copy and bss zero functions                                       */

typedef void (CYG_SYM_ADDRESS)(void);

// All these must use this type of address to stop them being given relocations
// relative to $gp (i.e. assuming they would be in .sdata)
extern CYG_SYM_ADDRESS __ram_data_start;
extern CYG_SYM_ADDRESS __ram_data_end;
extern CYG_SYM_ADDRESS __rom_data_start;    

#ifdef CYG_HAL_STARTUP_ROM      
void hal_copy_data(void)
{
    char *p = (char *)&__ram_data_start;
    char *q = (char *)&__rom_data_start;
    
    while( p != (char *)&__ram_data_end )
        *p++ = *q++;
}
#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;