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

//

//      m68k_stub.c

//

//      M68K gdb support

//

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

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

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

// This file is part of eCos, the Embedded Configurable Operating System.   

// Copyright (C) 2003, 2008 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     

// 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.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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 v2.                                               

//

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

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

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

// ####ECOSGPLCOPYRIGHTEND####                                              

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

//###DESCRIPTIONBEGIN####

//

// Author(s):     bartv

// Date:          2003-06-04

//

//###DESCRIPTIONEND####

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

#include <pkgconf/hal.h>

#include <pkgconf/hal_m68k.h>

#include <cyg/infra/cyg_type.h>

#include <cyg/infra/cyg_ass.h>

#include <cyg/infra/diag.h>

#include <cyg/hal/hal_arch.h>

#include <cyg/hal/hal_intr.h>

#include <cyg/hal/hal_if.h>

#include <cyg/hal/hal_stub.h>

// Translate between the eCos save state and what is expected by the gdb

// stubs. d0-d7/a0-a6 are in the right place already. SR/PS and the program

// counter need to come from variant-specific macros. The stack pointer

// can be determined from the saved context.

externC void

hal_get_gdb_registers(CYG_ADDRWORD* gdb_regs, HAL_SavedRegisters* ecos_regs)

{

    int     sr;

    int     pc;

    int     i;

    for (i = 0; i < 15; i++) {

        gdb_regs[i] = ecos_regs->da[i];

    }

    gdb_regs[15]    = (CYG_ADDRWORD) &(ecos_regs[1]);

    HAL_CONTEXT_PCSR_GET_SR(ecos_regs, sr);

    HAL_CONTEXT_PCSR_GET_PC(ecos_regs, pc);

    gdb_regs[16]    = sr;

    gdb_regs[17]    = pc;

}

externC void

hal_set_gdb_registers(HAL_SavedRegisters* ecos_regs, CYG_ADDRWORD* gdb_regs)

{

    int i;

    for (i = 0; i < 15; i++) {

        ecos_regs->da[i] = gdb_regs[i];

    }

    if (gdb_regs[15] != (CYG_ADDRWORD) &(ecos_regs[1])) {

        CYG_FAIL("gdb has requested a thread context switch - not supported,");

    }

    HAL_CONTEXT_PCSR_SET_SR(ecos_regs, gdb_regs[16]);

    HAL_CONTEXT_PCSR_SET_PC(ecos_regs, gdb_regs[17]);

}

#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS

externC int

__computeSignal(unsigned int trap_number)

{

    switch(trap_number) {

      case CYGNUM_HAL_EXCEPTION_DATA_ACCESS:

        return SIGBUS;

      case CYGNUM_HAL_EXCEPTION_DATA_UNALIGNED_ACCESS:

      case CYGNUM_HAL_EXCEPTION_SYSTEM_ERROR:

        return SIGSEGV;

      case CYGNUM_HAL_EXCEPTION_ILLEGAL_INSTRUCTION:

        return SIGILL;

      case CYGNUM_HAL_EXCEPTION_DIV_BY_ZERO:

        return SIGFPE;

      case CYGNUM_HAL_EXCEPTION_TRACE:

      case CYGNUM_HAL_VECTOR_TRAP0 ... CYGNUM_HAL_VECTOR_TRAP15:

      default:

        return SIGTRAP;

    }

}

externC int

__get_trap_number(void)

{

    int result = CYGNUM_HAL_EXCEPTION_SYSTEM_ERROR;

    if ((HAL_SavedRegisters*)0 != _hal_registers) {

        HAL_CONTEXT_PCSR_GET_EXCEPTION(_hal_registers, result);

    }

    return result;

}

externC void

set_pc(target_register_t pc)

{

    _registers[PC]  = pc;

}

// Single-stepping just involves setting the trace bit in the status register

externC void

__single_step(void)

{

    _registers[PS]  |= HAL_M68K_SR_T;

}

externC void

__clear_single_step(void)

{

    _registers[PS]  &= ~HAL_M68K_SR_T;

}

// This breakpoint support is (probably) not needed because

// single-stepping is supported instead.

externC void

__install_breakpoints(void)

{

}

externC void

__clear_breakpoints(void)

{

}

externC int

__is_breakpoint_function(void)

{

    return _registers[PC]   == (target_register_t)&_breakinst;

}

// The 68K has variable length instructions so skipping an instruction

// is messy. However __skipinst() is only used for a breakpoint

// instruction or for a trap, and these are always 2 bytes.

externC void

__skipinst(void)

{

    _registers[PC] += 2;

}

#endif