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// #========================================================================

// #

// #    vectors.S

// #

// #    M68K startup and exception handling.

// #

// #========================================================================

// ####ECOSGPLCOPYRIGHTBEGIN####

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

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

// Copyright (C) 2003, 2004, 2005, 2006, 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 

#include 

#include 

#include CYGBLD_HAL_TARGET_H

#include 

#include 

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

// These are for compatibility with older HALs

#ifdef HAL_M68K_EXCEPTION_VECTORS

# define _HAL_M68K_START_               HAL_M68K_EXCEPTION_VECTORS

# undef HAL_M68K_EXCEPTION_VECTORS

#endif

#ifdef HAL_M68K_COPY_ROM_DATA_TO_RAM

# define _HAL_M68K_COPY_ROM_DATA_TO_RAM_        1

# undef HAL_M68K_COPY_ROM_DATA_TO_RAM

#endif

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

// Exception vectors. Typically there are two exception vectors. There is

// one in flash which contains the h/w entry point. This is the section

// .m68k_start. Then there is the run-time set of exception vectors, typically

// held in RAM, which is the section .ram_vectors.  In addition to the pointers

// to the exception and interrupt VSRs that section contains the virtual vector

// table and any data that needs to be shared between RedBoot and the application,

// for example shadow copies of read-only registers.

//

// Typical scenarios include the following:

//

//   1) _HAL_M68K_START_ code relocates the flash from its boot location of 0x0

//      to somewhere else. _HAL_M68K_PLATFORM_SETUP1_ initializes SDRAM and

//      places it at 0x0. _HAL_M68K_START_ only contains the two initial exception

//      vector slots for the start address and stack, the RAM vectors are fully

//      populated at run-time by the architectural HAL. This is the typical

//      scenario for "large" systems.

//

//   2) for "small" systems where usually there is no RedBoot and the application

//      runs directly from flash, all the exception vectors also reside in flash

//      and are statically initialized. _HAL_M68K_START_ contains the full set

//      of vectors.

//

//   3) as a variant of (2) the run-time exception vectors may live in RAM,

//      typically relocated via the VBR register. The vectors will usually be

//      dynamically initialized, but if the application is loaded via gdb then

//      some code may be saved by static initialization.

        .section        ".m68k_start", "ax"

        // This will typically be defined by the platform HAL to get the world

        // in a sane state. It should do one-off initializations like getting

        // the system into a state matching the memory map. If booting from

        // flash it should also contain the initial PC and stack exception

        // vectors.

#ifdef _HAL_M68K_START_

        _HAL_M68K_START_

#endif

        .section        ".m68k_start.hal_m68k_exception_reset", "ax"

        // The actual entry point, as defined in the linker script. The exact

        // state of the system at this point depends on the configuration and

        // the processor.

        .global hal_m68k_exception_reset

        .type   hal_m68k_exception_reset, function

hal_m68k_exception_reset:

        // Make absolutely sure that the status register is in a

        // sensible state with interrupts disabled, irrespective of

        // the platform.

        mov.w   #0x2700,%sr

        // Platform-specific initialization. This will do things like starting

        // up the SDRAM controller. It may also run variant and processor

        // initialization code, but the platform HAL gets to decide the order.

#ifdef _HAL_M68K_PLATFORM_SETUP1_

        _HAL_M68K_PLATFORM_SETUP1_

#endif

        // All memory should now be running so we can get the C environment

        // set up. Clear BSS before switching to C mode

        .extern _hal_bss_start

        .extern _hal_bss_end

        move.l   # _hal_bss_start,%a0

        move.l   # _hal_bss_end,%a1

1:

        cmp.l   %a0,%a1

        ble     2f

        clr.l   (%a0)+

        jra     1b

2:

        // If booting from ROM, move .data from ROM to RAM

#ifdef _HAL_M68K_COPY_ROM_DATA_TO_RAM_

        .extern _hal_data_section_start_lma

        .extern _hal_data_section_end_lma

        .extern _hal_data_section_start_vma

        move.l  # _hal_data_section_start_lma, %a0

        move.l  # _hal_data_section_end_lma,   %a1

        move.l  # _hal_data_section_start_vma, %a2

1:

        cmp.l   %a0,%a1

        ble     2f

        mov.l   (%a0)+,(%a2)+

        jra     1b

2:

#endif

        // If there is an FPU, set the default mode

#ifdef CYGINT_HAL_M68K_VARIANT_FPU

        mov.w   # CYGNUM_HAL_M68K_FPU_CR_DEFAULT, %fpcr

#endif

        // If there is on-chip RAM, copy code and data there and clear

        // its BSS.

#ifdef _HAL_M68K_INITIALIZE_IRAM_

        .extern _hal_iram_text_section_start_lma

        .extern _hal_iram_data_section_end_lma

        .extern _hal_iram_text_section_start_vma

        .extern _hal_iram_bss_section_start

        .extern _hal_iram_bss_section_end

        move.l  # _hal_iram_text_section_start_lma, %a0

        move.l  # _hal_iram_data_section_end_lma,   %a1

        move.l  # _hal_iram_text_section_start_vma, %a2

1:

        cmp.l   %a0, %a1

        ble     2f

        mov.l   (%a0)+, (%a2)+

        jra     1b

2:

        move.l  # _hal_iram_bss_section_start, %a0

        move.l  # _hal_iram_bss_section_end,   %a1

3:

        cmp.l   %a0, %a1

        ble     4f

        clr.l   (%a0)+

        jra     3b

4:

#endif

        // Now we just need a valid stack and we can switch to C

        // for the remaining initialization. Clearing the frame

        // pointer may make life easier for gdb.

        mov.l   _HAL_M68K_STARTUP_STACK_,%sp

        suba.l  %a6, %a6

        .extern hal_m68k_c_startup

        jmp     hal_m68k_c_startup

// The exception vector table. Usually this will be held in RAM

// at location 0x0, although it may get moved around via e.g.

// the %vbr register. In addition to the exception vectors the

// virtual vector table is held here, as is any data that needs

// to be shared between RedBoot and eCos.

//

// Some targets in some configurations may define their own version

// of this, if for example the exception vector is held in ROM.

#if defined(_HAL_M68K_RAM_VECTORS_)

        _HAL_M68K_RAM_VECTORS_

#elif !defined(_HAL_M68K_RAM_VECTORS_DEFINED_)

        .section        ".ram_vectors", "aw", @nobits

# ifndef _HAL_M68K_SUPPRESS_RAM_VECTORS_VSR_TABLE_

        // Start with the interrupt/exception vectors.

        .global hal_m68k_vsr_table

hal_m68k_vsr_table:

        .rept   HAL_M68K_VSR_COUNT

        .long   0

        .endr

# endif

        // Next the virtual vector table. Space for this is usually allocated,

        // even if virtual vectors are not supported. That avoids confusion

        // if RedBoot and the application are configured differently. If a

        // platform will never support RedBoot, e.g. because of lack of memory,

        // then it can suppress the virtual vectors.

        //

        // The size of the table comes from ,

        // CYGNUM_CALL_IF_TABLE_SIZE, but that header cannot easily be included

        // in assembler.

# ifndef _HAL_M68K_SUPPRESS_VIRTUAL_VECTOR_

        .global hal_virtual_vector_table

hal_virtual_vector_table:

        .rept   64

        .long   0

        .endr

# endif

        // Allow the variant, processor and platform HALs to store additional

        // information in the global vectors section. Typically this is used for

        // data which needs to be shared between RedBoot and the application,

        // e.g. shadow copies of write-only hardware registers.

# ifdef _HAL_M68K_VARIANT_RAM_VECTORS_

        _HAL_M68K_VARIANT_RAM_VECTORS_

# endif

# ifdef _HAL_M68K_PROCESSOR_RAM_VECTORS_

        _HAL_M68K_PROCESSOR_RAM_VECTORS_

# endif

# ifdef _HAL_M68K_PLATFORM_RAM_VECTORS_

        _HAL_M68K_PLATFORM_RAM_VECTORS_

# endif

#endif  // _HAL_M68K_RAM_VECTORS_DEFINED_

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

// end of vectors.S