hal_stub.c

移植到WLIT项目的redboot源代码

    // 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) {
	for (i = 0; i < (sizeof(registers)/sizeof(registers[0])); i++)
	    orig_registers[i] = registers[i];
	orig_registers_set = 1;
	if (orig_registers[PC] == (target_register_t)&_breakinst)
	    orig_registers[PC] += HAL_BREAKINST_SIZE;
    }
	
#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;
    // Set exit vector to reset vector. This will allow automatic reset on
    // some platforms.
    __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 CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT
    {
        hal_virtual_comm_table_t* comm;
        int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);

        // Initialize mangler procs
        CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_MANGLER);
        comm = CYGACC_CALL_IF_CONSOLE_PROCS();
        CYGACC_COMM_IF_WRITE_SET(*comm, cyg_hal_gdb_diag_write);
        CYGACC_COMM_IF_READ_SET(*comm, cyg_hal_gdb_diag_read);
        CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_gdb_diag_putc);
        CYGACC_COMM_IF_GETC_SET(*comm, cyg_hal_gdb_diag_getc);
        CYGACC_COMM_IF_CONTROL_SET(*comm, cyg_hal_gdb_diag_control);

        // Now either restore the previous console channel, or let the
        // mangler stay in its place. The latter happens if the
        // console channel was previously unspecified, or if the
        // previous channel matches the used for GDB communication.
        if (CYGNUM_CALL_IF_SET_COMM_ID_EMPTY != cur
            && CYGNUM_HAL_VIRTUAL_VECTOR_DEBUG_CHANNEL != cur)
            CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);

        // Set the debug channel.
        CYGACC_CALL_IF_SET_DEBUG_COMM(CYGNUM_HAL_VIRTUAL_VECTOR_DEBUG_CHANNEL);
    }
#endif // CYGSEM_HAL_VIRTUAL_VECTOR_SUPPORT

#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_STUB_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;

    *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:
	strcpy(ptr, _hw_stop_str[_hw_stop_reason]);
	ptr += strlen(_hw_stop_str[_hw_stop_reason]);
	*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.
        target_register_t 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(PC) - sizeof(addr), 0);
    }
    ptr = __mem2hex((char *)&addr, ptr, sizeof(addr), 0);
    *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.
        target_register_t 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++ = ';';
    
    *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();
        state = 0;
        break;
    case CACHE_FLUSH:
        HAL_DCACHE_SYNC();
        break;
    case CACHE_NOOP:
        /* fall through */
    default:
        break;
    }
#ifdef HAL_DCACHE_IS_ENABLED
    HAL_DCACHE_IS_ENABLED(state);
#endif

    return state;
}

//-----------------------------------------------------------------------------
// Memory accessor functions.

// The __mem_fault_handler pointer is volatile since it is only
// set/cleared by the function below - which does not rely on any
// other functions, so the compiler may decide to not bother updating
// the pointer at all. If any of the memory accesses cause an
// exception, the pointer must be set to ensure the exception handler
// can make use of it.

void* volatile __mem_fault_handler = (void *)0;

/* These are the "arguments" to __do_read_mem and __do_write_mem, 
   which are passed as globals to avoid squeezing them thru
   __set_mem_fault_trap.  */

static volatile target_register_t memCount;

static void
__do_copy_mem (unsigned char* src, unsigned char* dst)
{
    unsigned long *long_dst;
    unsigned long *long_src;
    unsigned short *short_dst;
    unsigned short *short_src;

    __mem_fault = 1;                      /* Defaults to 'fail'. Is cleared */
                                          /* when the copy loop completes.  */
    __mem_fault_handler = &&err;

    // See if it's safe to do multi-byte, aligned operations
    while (memCount) {
        if ((memCount >= sizeof(long)) &&
            (((target_register_t)dst & (sizeof(long)-1)) == 0) &&
            (((target_register_t)src & (sizeof(long)-1)) == 0)) {
        
            long_dst = (unsigned long *)dst;
            long_src = (unsigned long *)src;

            *long_dst++ = *long_src++;
            memCount -= sizeof(long);

            dst = (unsigned char *)long_dst;
            src = (unsigned char *)long_src;
        } else if ((memCount >= sizeof(short)) &&
                   (((target_register_t)dst & (sizeof(short)-1)) == 0) &&
                   (((target_register_t)src & (sizeof(short)-1)) == 0)) {
            
            short_dst = (unsigned short *)dst;
            short_src = (unsigned short *)src;

            *short_dst++ = *short_src++;
            memCount -= sizeof(short);

            dst = (unsigned char *)short_dst;
            src = (unsigned char *)short_src;
        } else {
            *dst++ = *src++;
            memCount--;
        }
    }

    __mem_fault = 0;

 err:
    __mem_fault_handler = (void *)0;
}

/*
 * __read_mem_safe:
 * Get contents of target memory, abort on error.
 */

int
__read_mem_safe (void *dst, void *src, int count)
{
  memCount = count;
  __do_copy_mem((unsigned char*) src, (unsigned char*) dst);
  return count - memCount;      // return number of bytes successfully read
}

/*
 * __write_mem_safe:
 * Set contents of target memory, abort on error.
 */

int
__write_mem_safe (void *src, void *dst, int count)
{
  memCount = count;
  __do_copy_mem((unsigned char*) src, (unsigned char*) dst);
  return count - memCount;      // return number of bytes successfully written
}

//-----------------------------------------------------------------------------
// Target extras?!
int 
__process_target_query(char * pkt, char * out, int maxOut)
{ return 0 ; }
int 
__process_target_set(char * pkt, char * out, int maxout)
{ return 0 ; }
int 
__process_target_packet(char * pkt, char * out, int maxout)
{ return 0 ; }

// GDB string output, making sure interrupts are disabled.
// This function gets used by some diag output functions.
void 
hal_output_gdb_string(target_register_t str, int string_len)
{
    unsigned long __state;
    HAL_DISABLE_INTERRUPTS(__state);
    __output_gdb_string(str, string_len);
    HAL_RESTORE_INTERRUPTS(__state);
}

#endif // CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS