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

//

//      hal_stub.c

//

//      Helper functions for stub, specific to eCos HAL

//

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

//####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):   jskov (based on powerpc/cogent hal_stub.c)

// Contributors:jskov, dmoseley

// Date:        1999-02-12

// Purpose:     Helper functions for stub, specific to eCos HAL

// Description: Parts of the GDB stub requirements are provided by

//              the eCos HAL, rather than target and/or board specific

//              code. 

//

//####DESCRIPTIONEND####

//

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

#include <pkgconf/hal.h>

#ifdef CYGPKG_CYGMON

#include <pkgconf/cygmon.h>

#endif

#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS

#include <cyg/hal/hal_stub.h>           // Our header

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

#include <cyg/hal/hal_cache.h>          // HAL_xCACHE_x

#include <cyg/hal/hal_intr.h>           // interrupt disable/restore

#include <cyg/hal/hal_if.h>             // ROM calling interface

#include <cyg/hal/hal_misc.h>           // Helper functions

#ifdef CYGDBG_HAL_DEBUG_GDB_THREAD_SUPPORT

#include <cyg/hal/dbg-threads-api.h>    // dbg_currthread_id

#endif

#ifdef USE_LONG_NAMES_FOR_ENUM_REGNAMES

#ifndef PC

#define PC REG_PC

#endif

#ifndef SP

#define SP REG_SP

#endif

#endif

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

// Extra eCos data.

// Some architectures use registers of different sizes, so NUMREGS

// alone is not suffucient to size the register save area. For those

// architectures, HAL_STUB_REGISTERS_SIZE is defined as the number

// of target_register_t sized elements in the register save area.

#ifndef HAL_STUB_REGISTERS_SIZE

#define HAL_STUB_REGISTERS_SIZE NUMREGS

#endif

// Saved registers.

HAL_SavedRegisters *_hal_registers;

target_register_t registers[HAL_STUB_REGISTERS_SIZE];

target_register_t alt_registers[HAL_STUB_REGISTERS_SIZE] ;  // Thread or saved process state

target_register_t * _registers = registers;                 // Pointer to current set of registers

target_register_t orig_registers[HAL_STUB_REGISTERS_SIZE];  // Registers to get back to original state

#if defined(HAL_STUB_HW_WATCHPOINT) || defined(HAL_STUB_HW_BREAKPOINT)

static int  _hw_stop_reason;   // Reason we were stopped by hw.

//#define HAL_STUB_HW_SEND_STOP_REASON_TEXT

#ifdef CYGINT_HAL_ARM_ARCH_XSCALE

#define HAL_STUB_HW_SEND_STOP_REASON_TEXT

#endif

#ifdef HAL_STUB_HW_SEND_STOP_REASON_TEXT

// strings indexed by hw stop reasons defined in hal_stub.h

// Not all GDBs understand this.

static const char * const _hw_stop_str[] = {

    "",

    "hbreak",

    "watch",

    "rwatch",

    "awatch"

};

#endif // HAL_STUB_HW_SEND_STOP_REASON_TEXT

static void *_watch_data_addr; // The data address if stopped by watchpoint

#endif // defined(HAL_STUB_HW_WATCHPOINT) || defined(HAL_STUB_HW_BREAKPOINT)

// Register validity checking

#ifdef CYGHWR_REGISTER_VALIDITY_CHECKING

int registers_valid[NUMREGS];

int *_registers_valid = registers_valid;

#endif

#ifndef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT // this should go away

// Interrupt control.

static volatile __PFI __interruptible_control;

#endif

// Some architectures need extras regs reported in T packet

#ifndef HAL_STUB_ARCH_T_PACKET_EXTRAS

#define HAL_STUB_ARCH_T_PACKET_EXTRAS(x)

#endif

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

// Register access

#ifndef CYGARC_STUB_REGISTER_ACCESS_DEFINED

// Return the currently-saved value corresponding to register REG of

// the exception context.

target_register_t

get_register (regnames_t reg)

{

    return _registers[reg];

}

#endif

#ifdef CYGHWR_REGISTER_VALIDITY_CHECKING

// Return the validity of register REG.

int

get_register_valid (regnames_t reg)

{

    return _registers_valid[reg];

}

#endif

#ifndef CYGARC_STUB_REGISTER_ACCESS_DEFINED

// Store VALUE in the register corresponding to WHICH in the exception

// context.

void

put_register (regnames_t which, target_register_t value)

{

#ifdef CYGPKG_HAL_MIPS_VR4300

    // This is a rather nasty kludge to compensate for the fact that

    // the VR4300 GDB is rather old and does not support proper 64 bit

    // registers. The only time this really matters is when setting

    // the PC after loading an executable. So here we detect this case

    // and artificially sign extend it. 

    if( which == PC && (value & 0x0000000080000000ULL ) )

    {

        value |= 0xFFFFFFFF00000000ULL;

    }

#endif    

    _registers[which] = value;

}

#endif // CYGARC_STUB_REGISTER_ACCESS_DEFINED

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

// Serial stuff

#ifdef CYGPKG_CYGMON

extern void ecos_bsp_console_putc(char);

extern char ecos_bsp_console_getc(void);

#endif

// Write C to the current serial port.

void

putDebugChar (int c)

{

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

    __call_if_debug_procs_t __debug_procs = CYGACC_CALL_IF_DEBUG_PROCS();

    CYGACC_COMM_IF_PUTC(*__debug_procs, c);

#elif defined(CYGPKG_CYGMON)

    ecos_bsp_console_putc(c);

#else

    HAL_STUB_PLATFORM_PUT_CHAR(c);

#endif

}

// Read one character from the current serial port.

int

getDebugChar (void)

{

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

    __call_if_debug_procs_t __debug_procs = CYGACC_CALL_IF_DEBUG_PROCS();

    return CYGACC_COMM_IF_GETC(*__debug_procs);

#elif defined(CYGPKG_CYGMON)

    return ecos_bsp_console_getc();

#else

    return HAL_STUB_PLATFORM_GET_CHAR();

#endif

}

// Flush output channel

void

hal_flush_output(void)

{

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

    __call_if_debug_procs_t __debug_procs = CYGACC_CALL_IF_DEBUG_PROCS();

    CYGACC_COMM_IF_CONTROL(*__debug_procs, __COMMCTL_FLUSH_OUTPUT);

#endif

}

// Set the baud rate for the current serial port.

void

__set_baud_rate (int baud)

{

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

    __call_if_debug_procs_t __debug_procs = CYGACC_CALL_IF_DEBUG_PROCS();

    CYGACC_COMM_IF_CONTROL(*__debug_procs, __COMMCTL_SETBAUD, baud);

#elif defined(CYGPKG_CYGMON)

    // FIXME!

#else

    HAL_STUB_PLATFORM_SET_BAUD_RATE(baud);

#endif

}

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

// GDB interrupt (BREAK) support.

#ifdef CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

#ifndef CYGPKG_HAL_ARM

#if (HAL_BREAKINST_SIZE == 1)

typedef cyg_uint8 t_inst;

#elif (HAL_BREAKINST_SIZE == 2)

typedef cyg_uint16 t_inst;

#elif (HAL_BREAKINST_SIZE == 4)

typedef cyg_uint32 t_inst;

#else

#error "Don't know how to handle that size"

#endif

typedef struct

{

  t_inst *targetAddr;

  t_inst savedInstr;

} instrBuffer;

static instrBuffer break_buffer;

volatile int cyg_hal_gdb_running_step = 0;

void

cyg_hal_gdb_place_break (target_register_t pc)

{

    cyg_hal_gdb_interrupt( pc ); // Let's hope this becomes a drop-through:

}

void

cyg_hal_gdb_interrupt (target_register_t pc)

{

    CYGARC_HAL_SAVE_GP();

    // Clear flag that we Continued instead of Stepping

    cyg_hal_gdb_running_step = 0;

    // and override existing break? So that a ^C takes effect...

    if (NULL != break_buffer.targetAddr)

        cyg_hal_gdb_remove_break( (target_register_t)break_buffer.targetAddr );

    if (NULL == break_buffer.targetAddr) {

        break_buffer.targetAddr = (t_inst*) pc;

        break_buffer.savedInstr = *(t_inst*)pc;

        *(t_inst*)pc = (t_inst)HAL_BREAKINST;

        __data_cache(CACHE_FLUSH);

        __instruction_cache(CACHE_FLUSH);

    }

    CYGARC_HAL_RESTORE_GP();

}

int

cyg_hal_gdb_remove_break (target_register_t pc)

{

    if ( cyg_hal_gdb_running_step )

        return 0;

    if ((t_inst*)pc == break_buffer.targetAddr) {

        *(t_inst*)pc = break_buffer.savedInstr;

        break_buffer.targetAddr = NULL;

        __data_cache(CACHE_FLUSH);

        __instruction_cache(CACHE_FLUSH);

        return 1;

    }

    return 0;

}

int

cyg_hal_gdb_break_is_set (void)

{

    if (NULL != break_buffer.targetAddr) {

        return 1;

    }

    return 0;

}

#endif // CYGPKG_HAL_ARM

#endif // CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

// Use this function to disable serial interrupts whenever reply

// characters are expected from GDB.  The reason we want to control

// whether the target can be interrupted or not is simply that GDB on

// the host will be sending acknowledge characters/commands while the

// stub is running - if serial interrupts were still active, the

// characters would never reach the (polling) getDebugChar.

static void

interruptible(int state)

{

    static int __interrupts_suspended = 0;

    if (state) {

        __interrupts_suspended--;

        if (0 >= __interrupts_suspended) {

            __interrupts_suspended = 0;

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT // this _check_ should go away

            {

                hal_virtual_comm_table_t* __chan;

                __chan = CYGACC_CALL_IF_DEBUG_PROCS();

                CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_ENABLE);

            }

#else                

            if (__interruptible_control)

                __interruptible_control(1);

#endif

        }

    } else {

        __interrupts_suspended++;

        if (1 == __interrupts_suspended)

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT // this _check_ should go away

            {

                hal_virtual_comm_table_t* __chan;

                __chan = CYGACC_CALL_IF_DEBUG_PROCS();

                CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_DISABLE);

            }

#else                

            if (__interruptible_control)

                __interruptible_control(0);

#endif

    }

}

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

// eCos stub entry and exit magic.

#ifdef CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

int cyg_hal_gdb_break;

#endif

// Called at stub *kill*

static void

handle_exception_exit( void )

{

    int i;

    for (i = 0; i < (sizeof(registers)/sizeof(registers[0])); i++)

        registers[i] = orig_registers[i];

}

// Called at stub *entry*

static void

handle_exception_cleanup( void )

{

    static int orig_registers_set = 0;

    interruptible(0);

    // Expand the HAL_SavedRegisters structure into the GDB register

    // array format.

    HAL_GET_GDB_REGISTERS(&registers[0], _hal_registers);

    _registers = &registers[0];

    if (!orig_registers_set) {

        int i;

        for (i = 0; i < (sizeof(registers)/sizeof(registers[0])); i++)

            orig_registers[i] = registers[i];

        _registers = &orig_registers[0];

        if (__is_breakpoint_function ())

            __skipinst ();

        _registers = &registers[0];

        orig_registers_set = 1;

    }

#ifdef HAL_STUB_PLATFORM_STUBS_FIXUP

    // Some architectures may need to fix the PC in case of a partial

    // or fully executed trap instruction. GDB only takes correct action

    // when the PC is pointing to the breakpoint instruction it set.

    // 

    // Most architectures would leave PC pointing at the trap

    // instruction itself though, and so do not need to do anything

    // special.

    HAL_STUB_PLATFORM_STUBS_FIXUP();

#endif

#ifdef CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

    // If we continued instead of stepping, when there was a break set

    // ie. we were stepping within a critical region, clear the break, and

    // that flag.  If we stopped for some other reason, this has no effect.

    if ( cyg_hal_gdb_running_step ) {

        cyg_hal_gdb_running_step = 0;

        cyg_hal_gdb_remove_break(get_register (PC));

    }

    // FIXME: (there may be a better way to do this)

    // If we hit a breakpoint set by the gdb interrupt stub, make it

    // seem like an interrupt rather than having hit a breakpoint.

    cyg_hal_gdb_break = cyg_hal_gdb_remove_break(get_register (PC));

#endif

#if defined(HAL_STUB_HW_WATCHPOINT) || defined(HAL_STUB_HW_BREAKPOINT)

    // For HW watchpoint/breakpoint support, we need to know if we

    // stopped because of watchpoint or hw break. We do that here

    // before GDB has a chance to remove the watchpoints and save

    // the information for later use in building response packets.

    _hw_stop_reason = HAL_STUB_IS_STOPPED_BY_HARDWARE(_watch_data_addr);

#endif    

}

// Called at stub *exit*

static void

handle_exception_init( void )

{

    // Compact register array again.

    HAL_SET_GDB_REGISTERS(_hal_registers, &registers[0]);

    interruptible(1);

}

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

// Initialization.

// Signal handler.

int

cyg_hal_process_signal (int signal)

{

    // We don't care about the signal (atm).

    return 0;

}

// Install the standard set of trap handlers for the stub.

void

__install_traps (void)

{

    // Set signal handling vector so we can treat 'C<signum>' as 'c'.

    __process_signal_vec = &cyg_hal_process_signal;

    __process_exit_vec = &handle_exception_exit;

    __cleanup_vec = &handle_exception_cleanup;

    __init_vec    = &handle_exception_init;

#ifndef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT // this should go away

#ifdef CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

    // Control of GDB interrupts.

    __interruptible_control = HAL_STUB_PLATFORM_INTERRUPTIBLE;

#endif

#endif

    // Nothing further to do, handle_exception will be called when an

    // exception occurs.

}

// Initialize the hardware.

void

initHardware (void)

{

    static int initialized = 0;

    if (initialized)

        return;

    initialized = 1;

    // Get serial port initialized.

    HAL_STUB_PLATFORM_INIT_SERIAL();

#ifdef HAL_STUB_PLATFORM_INIT

    // If the platform defines any initialization code, call it here.

    HAL_STUB_PLATFORM_INIT();

#endif        

#ifndef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT // this should go away

#ifdef CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT

    // Get interrupt handler initialized.

    HAL_STUB_PLATFORM_INIT_BREAK_IRQ();

#endif

#endif // !CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

}

// Reset the board.

void

__reset (void)

{

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

    __call_if_reset_t *__rom_reset = CYGACC_CALL_IF_RESET_GET();

    if (__rom_reset)

        (*__rom_reset)();

#else

    HAL_PLATFORM_RESET();

#endif

}

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

// Breakpoint support.

#ifndef CYGPKG_HAL_ARM

// This function will generate a breakpoint exception.  It is used at

// the beginning of a program to sync up with a debugger and can be

// used otherwise as a quick means to stop program execution and

// "break" into the debugger.

void

breakpoint()

{

    HAL_BREAKPOINT(_breakinst);

}

// This function returns the opcode for a 'trap' instruction.

unsigned long

__break_opcode ()

{

  return HAL_BREAKINST;

}

#endif

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

// Write the 'T' packet in BUFFER. SIGVAL is the signal the program received.

void

__build_t_packet (int sigval, char *buf)

{

    target_register_t addr;

    char *ptr = buf;

    target_register_t extend_val = 0;

    *ptr++ = 'T';

    *ptr++ = __tohex (sigval >> 4);

    *ptr++ = __tohex (sigval);

#ifdef CYGDBG_HAL_DEBUG_GDB_THREAD_SUPPORT

    // Include thread ID if thread manipulation is required.

    {

        int id = dbg_currthread_id ();

        if (id != 0) {

            *ptr++ = 't';

            *ptr++ = 'h';

            *ptr++ = 'r';

            *ptr++ = 'e';

            *ptr++ = 'a';

            *ptr++ = 'd';

            *ptr++ = ':';

#if (CYG_BYTEORDER == CYG_LSBFIRST)

            // FIXME: Temporary workaround for PR 18903. Thread ID must be

            // big-endian in the T packet.

            {

                unsigned char* bep = (unsigned char*)&id;

                int be_id;

                be_id = id;

                *bep++ = (be_id >> 24) & 0xff ;

                *bep++ = (be_id >> 16) & 0xff ;

                *bep++ = (be_id >> 8) & 0xff ;

                *bep++ = (be_id & 0xff) ;

            }

#endif

            ptr = __mem2hex((char *)&id, ptr, sizeof(id), 0);

            *ptr++ = ';';

        }

    }

#endif

#ifdef HAL_STUB_HW_WATCHPOINT

    switch(_hw_stop_reason) {

      case HAL_STUB_HW_STOP_WATCH:

      case HAL_STUB_HW_STOP_RWATCH:

      case HAL_STUB_HW_STOP_AWATCH:

#ifdef HAL_STUB_HW_SEND_STOP_REASON_TEXT

        // Not all GDBs understand this.

        strcpy(ptr, _hw_stop_str[_hw_stop_reason]);

        ptr += strlen(_hw_stop_str[_hw_stop_reason]);

#endif

        *ptr++ = ':';

        // Send address MSB first

        ptr += __intToHex(ptr, (target_register_t)_watch_data_addr,

                          sizeof(_watch_data_addr) * 8);

        *ptr++ = ';';

        break;

      default:

        break;

    }

#endif

    *ptr++ = __tohex (PC >> 4);

    *ptr++ = __tohex (PC);

    *ptr++ = ':';

    addr = get_register (PC);

    if (sizeof(addr) < REGSIZE(PC))

    {

        // GDB is expecting REGSIZE(PC) number of bytes.

        // We only have sizeof(addr) number.  Let's fill

        // the appropriate number of bytes intelligently.

#ifdef CYGARC_SIGN_EXTEND_REGISTERS

        {

            unsigned long bits_in_addr = (sizeof(addr) << 3);  // ie Size in bytes * 8

            target_register_t sign_bit_mask = (1 << (bits_in_addr - 1));

            if ((addr & sign_bit_mask) == sign_bit_mask)

                extend_val = ~0;

        }

#endif

    }

#if (CYG_BYTEORDER == CYG_MSBFIRST)

    ptr = __mem2hex((char *)&extend_val, ptr, REGSIZE(PC) - sizeof(addr), 0);

#endif

    ptr = __mem2hex((char *)&addr, ptr, sizeof(addr), 0);

#if (CYG_BYTEORDER == CYG_LSBFIRST)

    ptr = __mem2hex((char *)&extend_val, ptr, REGSIZE(PC) - sizeof(addr), 0);

#endif

    *ptr++ = ';';

    *ptr++ = __tohex (SP >> 4);

    *ptr++ = __tohex (SP);

    *ptr++ = ':';

    addr = (target_register_t) get_register (SP);

    if (sizeof(addr) < REGSIZE(SP))

    {

        // GDB is expecting REGSIZE(SP) number of bytes.

        // We only have sizeof(addr) number.  Let's fill

        // the appropriate number of bytes intelligently.

        extend_val = 0;

#ifdef CYGARC_SIGN_EXTEND_REGISTERS

        {

            unsigned long bits_in_addr = (sizeof(addr) << 3);  // ie Size in bytes * 8

            target_register_t sign_bit_mask = (1 << (bits_in_addr - 1));

            if ((addr & sign_bit_mask) == sign_bit_mask)

                extend_val = ~0;

        }

#endif

        ptr = __mem2hex((char *)&extend_val, ptr, REGSIZE(SP) - sizeof(addr), 0);

    }

    ptr = __mem2hex((char *)&addr, ptr, sizeof(addr), 0);

    *ptr++ = ';';

    HAL_STUB_ARCH_T_PACKET_EXTRAS(ptr);

    *ptr++ = 0;

}

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

// Cache functions.

// Perform the specified operation on the instruction cache. 

// Returns 1 if the cache is enabled, 0 otherwise.

int

__instruction_cache (cache_control_t request)

{

    int state = 1;

    switch (request) {

    case CACHE_ENABLE:

        HAL_ICACHE_ENABLE();

        break;

    case CACHE_DISABLE:

        HAL_ICACHE_DISABLE();

        state = 0;

        break;

    case CACHE_FLUSH:

        HAL_ICACHE_SYNC();

        break;

    case CACHE_NOOP:

        /* fall through */

    default:

        break;

    }

#ifdef HAL_ICACHE_IS_ENABLED

    HAL_ICACHE_IS_ENABLED(state);

#endif

    return state;

}

// Perform the specified operation on the data cache. 

// Returns 1 if the cache is enabled, 0 otherwise.

int

__data_cache (cache_control_t request)

{

    int state = 1;

    switch (request) {

    case CACHE_ENABLE:

        HAL_DCACHE_ENABLE();

        break;

    case CACHE_DISABLE:

        HAL_DCACHE_DISABLE();