//=============================================================================
//
//      hal_if.c
//
//      ROM/RAM interfacing functions
//
//=============================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000, 2001 Red Hat, Inc.
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//=============================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   jskov
// Contributors:jskov
// Date:        2000-06-07
//
//####DESCRIPTIONEND####
//
//=============================================================================

#include <pkgconf/hal.h>

#ifdef CYGPKG_KERNEL
# include <pkgconf/kernel.h>
#endif

#include <cyg/infra/cyg_ass.h>          // assertions

#include <cyg/hal/hal_arch.h>           // set/restore GP

#include <cyg/hal/hal_io.h>             // IO macros
#include <cyg/hal/hal_if.h>             // our interface

#include <cyg/hal/hal_diag.h>           // Diag IO
#include <cyg/hal/hal_misc.h>           // User break

#include <cyg/hal/hal_stub.h>           // stub functionality

#include <cyg/hal/hal_intr.h>           // hal_vsr_table and others

#ifdef CYGPKG_REDBOOT
#include <pkgconf/redboot.h>
#ifdef CYGSEM_REDBOOT_FLASH_CONFIG
#include <redboot.h>
#include <flash_config.h>
#endif
#endif

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

externC void patch_dbg_syscalls(void * vector);
externC void init_thread_syscall(void * vector);

//--------------------------------------------------------------------------
// Implementations and function wrappers for monitor services

// flash config state queries
#ifdef CYGSEM_REDBOOT_FLASH_CONFIG

static __call_if_flash_cfg_op_fn_t flash_config_op;

static cyg_bool
flash_config_op( int op, char * key, void *val, int type)
{
    switch ( op ) {
    case CYGNUM_CALL_IF_FLASH_CFG_GET:
        return flash_get_config( key, val, type );
    default:
        // nothing else supported yet - though it is expected that "set"
        // will fit the same set of arguments, potentially.
        break;
    }
    return 0;
}
#endif

//----------------------------
// Delay uS
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_DELAY_US

static __call_if_delay_us_t delay_us;

static void
delay_us(cyg_int32 usecs)
{
    CYGARC_HAL_SAVE_GP();
#ifdef CYGPKG_KERNEL
    {
        cyg_int32 start, elapsed;
        cyg_int32 usec_ticks, slice;

        // How many ticks total we should wait for.
        usec_ticks = usecs*CYGNUM_KERNEL_COUNTERS_RTC_PERIOD;
        usec_ticks /= CYGNUM_HAL_RTC_NUMERATOR/CYGNUM_HAL_RTC_DENOMINATOR/1000;

        do {
            // Spin in slices of 1/2 the RTC period. Allows interrupts
            // time to run without messing up the algorithm. If we spun
            // for 1 period (or more) of the RTC, there'd be also problems
            // figuring out when the timer wrapped.  We may lose a tick or
            // two for each cycle but it shouldn't matter much.
            slice = usec_ticks % (CYGNUM_KERNEL_COUNTERS_RTC_PERIOD / 2);
    
            HAL_CLOCK_READ(&start);
            do {
                HAL_CLOCK_READ(&elapsed);
                elapsed = (elapsed - start); // counts up!
                if (elapsed < 0)
                    elapsed += CYGNUM_KERNEL_COUNTERS_RTC_PERIOD;
            } while (elapsed < slice);
            
            // Adjust by elapsed, not slice, since an interrupt may have
            // been stalling us for some time.
            usec_ticks -= elapsed;
        } while (usec_ticks > 0);
    }
#else // CYGPKG_KERNEL
#ifdef HAL_DELAY_US
    // Use a HAL feature if defined
    HAL_DELAY_US(usecs);
#else
    // If no accurate delay mechanism, just spin for a while. Having
    // an inaccurate delay is much better than no delay at all. The
    // count of 10 should mean the loop takes something resembling
    // 1us on most CPUs running between 30-100MHz [depends on how many
    // instructions this compiles to, how many dispatch units can be
    // used for the simple loop, actual CPU frequency, etc]
    while (usecs-- > 0) {
        int i;
        for (i = 0; i < 10; i++);
    }
#endif // HAL_DELAY_US
#endif // CYGPKG_KERNEL
    CYGARC_HAL_RESTORE_GP();
}
#endif // CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_DELAY_US

// Reset functions
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_RESET

static __call_if_reset_t reset;

static void
reset(void)
{
    CYGARC_HAL_SAVE_GP();
    // With luck, the platform defines some magic that will cause a hardware
    // reset.
    HAL_PLATFORM_RESET();

#ifdef HAL_PLATFORM_RESET_ENTRY
    // If that's not the case (above is an empty statement) there may
    // be defined an address we can jump to - and effectively
    // reinitialize the system. Not quite as good as a reset, but it
    // is often enough.
    goto *HAL_PLATFORM_RESET_ENTRY;

#else
#error " no RESET_ENTRY"
#endif

    CYGARC_HAL_RESTORE_GP();
}

// This is the system's default kill signal routine. Unless overridden
// by the application, it will cause a board reset when GDB quits the
// connection. (The user can avoid the reset by using the GDB 'detach'
// command instead of 'kill' or 'quit').
static int
kill_by_reset(int __irq_nr, void* __regs)
{
    CYGARC_HAL_SAVE_GP();

    reset();

    CYGARC_HAL_RESTORE_GP();
    return 0;
}
#endif

//------------------------------------
// NOP service
#if defined(CYGSEM_HAL_VIRTUAL_VECTOR_INIT_WHOLE_TABLE) || \
    defined(CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_COMMS)
static int
nop_service(void)
{
    // This is the default service. It always returns false (0), and
    // _does not_ trigger any assertions. Clients must either cope
    // with the service failure or assert.
    return 0;
}
#endif

//----------------------------------
// Comm controls
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_COMMS

#ifdef CYGNUM_HAL_VIRTUAL_VECTOR_AUX_CHANNELS
#define CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS \
  (CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS+CYGNUM_HAL_VIRTUAL_VECTOR_AUX_CHANNELS)
#else
#define CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS \
  CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS
#endif

static hal_virtual_comm_table_t comm_channels[CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS+1];

static int
set_debug_comm(int __comm_id)
{
    static int __selected_id = CYGNUM_CALL_IF_SET_COMM_ID_EMPTY;
    hal_virtual_comm_table_t* __chan;
    int interrupt_state = 0;
    int res = 1, update = 0;
    CYGARC_HAL_SAVE_GP();

    CYG_ASSERT(__comm_id >= CYGNUM_CALL_IF_SET_COMM_ID_MANGLER
               && __comm_id < CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS,
               "Invalid channel");

    switch (__comm_id) {
    case CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT:
        if (__selected_id > 0)
            res = __selected_id-1;
        else if (__selected_id == 0)
            res = CYGNUM_CALL_IF_SET_COMM_ID_MANGLER;
        else 
            res = __selected_id;
        break;

    case CYGNUM_CALL_IF_SET_COMM_ID_EMPTY:
        CYGACC_CALL_IF_DEBUG_PROCS_SET(0);
        __selected_id = __comm_id;
        break;

    case CYGNUM_CALL_IF_SET_COMM_ID_MANGLER:
        __comm_id = 0;
        update = 1;
        break;

    default:
        __comm_id++;                    // skip mangler entry
        update = 1;
        break;
    }

    if (update) {
        // Find the interrupt state of the channel.
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();
        if (__chan)
            interrupt_state = CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_DISABLE);

        __selected_id = __comm_id;
        CYGACC_CALL_IF_DEBUG_PROCS_SET(comm_channels[__comm_id]);

        // Set interrupt state on the new channel.
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();
        if (interrupt_state)
            CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_ENABLE);
        else
            CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_DISABLE);
    }

    CYGARC_HAL_RESTORE_GP();
    return res;
}

static int
set_console_comm(int __comm_id)
{
    static int __selected_id = CYGNUM_CALL_IF_SET_COMM_ID_EMPTY;
    int res = 1, update = 0;
    CYGARC_HAL_SAVE_GP();

    CYG_ASSERT(__comm_id >= CYGNUM_CALL_IF_SET_COMM_ID_MANGLER
               && __comm_id < CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS,
               "Invalid channel");

    switch (__comm_id) {
    case CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT:
        if (__selected_id > 0)
            res = __selected_id-1;
        else if (__selected_id == 0)
            res = CYGNUM_CALL_IF_SET_COMM_ID_MANGLER;
        else
            res = __selected_id;
        break;

    case CYGNUM_CALL_IF_SET_COMM_ID_EMPTY:
        CYGACC_CALL_IF_CONSOLE_PROCS_SET(0);
        __selected_id = __comm_id;
        break;

    case CYGNUM_CALL_IF_SET_COMM_ID_MANGLER:
        __comm_id = 0;
        update = 1;
        break;

    default:
        __comm_id++;                    // skip mangler entry
        update = 1;
        break;
    }
    
    if (update) {
        __selected_id = __comm_id;
    
        CYGACC_CALL_IF_CONSOLE_PROCS_SET(comm_channels[__comm_id]);
    }

    CYGARC_HAL_RESTORE_GP();
    return res;
}
#endif

//----------------------------------
// Cache functions
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_CACHE

static void
flush_icache(void *__p, int __nbytes)
{
    CYGARC_HAL_SAVE_GP();
#ifdef HAL_ICACHE_FLUSH
    HAL_ICACHE_FLUSH( __p , __nbytes );
#elif defined(HAL_ICACHE_INVALIDATE)
    HAL_ICACHE_INVALIDATE();
#endif
    CYGARC_HAL_RESTORE_GP();
}

static void
flush_dcache(void *__p, int __nbytes)
{
    CYGARC_HAL_SAVE_GP();
#ifdef HAL_DCACHE_FLUSH
    HAL_DCACHE_FLUSH( __p , __nbytes );
#elif defined(HAL_DCACHE_INVALIDATE)
    HAL_DCACHE_INVALIDATE();
#endif
    CYGARC_HAL_RESTORE_GP();
}
#endif

#if defined(CYGSEM_HAL_VIRTUAL_VECTOR_DIAG)
//-----------------------------------------------------------------------------
// GDB console output mangler (O-packetizer)
// COMMS init function at end.

// This gets called via the virtual vector console comms entry and
// handles O-packetization. The debug comms entries are used for the
// actual device IO.
static cyg_uint8
cyg_hal_diag_mangler_gdb_getc(void* __ch_data)
{
    cyg_uint8 __ch;
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();
    CYGARC_HAL_SAVE_GP();

    __ch = CYGACC_COMM_IF_GETC(*__chan);

    CYGARC_HAL_RESTORE_GP();

    return __ch;
}

static void
cyg_hal_diag_mangler_gdb_putc(void* __ch_data, cyg_uint8 c)
{
    static char line[100];
    static int pos = 0;
    int tries = CYGNUM_HAL_DEBUG_GDB_PROTOCOL_RETRIES;

    // No need to send CRs
    if( c == '\r' ) return;

    CYGARC_HAL_SAVE_GP();

    line[pos++] = c;

    if( c == '\n' || pos == sizeof(line) )
    {
        CYG_INTERRUPT_STATE old;
        hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();

        // Disable interrupts. This prevents GDB trying to interrupt us
        // while we are in the middle of sending a packet. The serial
        // receive interrupt will be seen when we re-enable interrupts
        // later.
#if defined(CYG_HAL_STARTUP_ROM) \
    || !defined(CYG_HAL_GDB_ENTER_CRITICAL_IO_REGION)
        HAL_DISABLE_INTERRUPTS(old);
#else
        CYG_HAL_GDB_ENTER_CRITICAL_IO_REGION(old);
#endif
        
        // Only wait 500ms for data to arrive - avoid "stuck" connections
        CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_SET_TIMEOUT, CYGNUM_HAL_DEBUG_GDB_PROTOCOL_TIMEOUT);

        while(1)
        {
            static const char hex[] = "0123456789ABCDEF";
            cyg_uint8 csum = 0, c1;
            int i;
        
            CYGACC_COMM_IF_PUTC(*__chan, '$');
            CYGACC_COMM_IF_PUTC(*__chan, 'O');
            csum += 'O';
            for( i = 0; i < pos; i++ )
            {
                char ch = line[i];
                char h = hex[(ch>>4)&0xF];
                char l = hex[ch&0xF];
                CYGACC_COMM_IF_PUTC(*__chan, h);
                CYGACC_COMM_IF_PUTC(*__chan, l);
                csum += h;
                csum += l;
            }
            CYGACC_COMM_IF_PUTC(*__chan, '#');
            CYGACC_COMM_IF_PUTC(*__chan, hex[(csum>>4)&0xF]);
            CYGACC_COMM_IF_PUTC(*__chan, hex[csum&0xF]);

        nak:
            if (CYGACC_COMM_IF_GETC_TIMEOUT(*__chan, &c1) == 0) {
                c1 = '-';
                if (--tries == 0) c1 = '+';
            }

            if( c1 == '+' ) break;

            if( cyg_hal_is_break( &c1 , 1 ) ) {
                // Caller's responsibility to react on this.
                CYGACC_CALL_IF_CONSOLE_INTERRUPT_FLAG_SET(1);
                break;
            }
            if( c1 != '-' ) goto nak;
        }

        pos = 0;
        // And re-enable interrupts
#if defined(CYG_HAL_STARTUP_ROM) \
    || !defined(CYG_HAL_GDB_ENTER_CRITICAL_IO_REGION)
        HAL_RESTORE_INTERRUPTS(old);
#else
        CYG_HAL_GDB_LEAVE_CRITICAL_IO_REGION(old);
#endif
    }

    CYGARC_HAL_RESTORE_GP();
}

static void
cyg_hal_diag_mangler_gdb_write(void* __ch_data,
                               const cyg_uint8* __buf, cyg_uint32 __len)
{
    CYGARC_HAL_SAVE_GP();

    while(__len-- > 0)
        cyg_hal_diag_mangler_gdb_putc(__ch_data, *__buf++);

    CYGARC_HAL_RESTORE_GP();
}

static void
cyg_hal_diag_mangler_gdb_read(void* __ch_data, 
                              cyg_uint8* __buf, cyg_uint32 __len)
{
    CYGARC_HAL_SAVE_GP();

    while(__len-- > 0)
        *__buf++ = cyg_hal_diag_mangler_gdb_getc(__ch_data);

    CYGARC_HAL_RESTORE_GP();
}

static int
cyg_hal_diag_mangler_gdb_control(void *__ch_data, 
                                 __comm_control_cmd_t __func, ...)
{
    // Do nothing (yet).
    return 0;
}

// This is the COMMS init function. It gets called both by the stubs
// and diag init code to initialize the COMMS mangler channel table -
// that's all. The callers have to decide whether to actually use this
// channel.
void
cyg_hal_diag_mangler_gdb_init(void)
{
    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_diag_mangler_gdb_write);
    CYGACC_COMM_IF_READ_SET(*comm, cyg_hal_diag_mangler_gdb_read);
    CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_diag_mangler_gdb_putc);
    CYGACC_COMM_IF_GETC_SET(*comm, cyg_hal_diag_mangler_gdb_getc);
    CYGACC_COMM_IF_CONTROL_SET(*comm, cyg_hal_diag_mangler_gdb_control);
    
    // Restore the original console channel.
    CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);
}

//-----------------------------------------------------------------------------
// Null console output mangler
// COMMS init function at end.

// This gets called via the virtual vector console comms entry and
// just forwards IO to the debug comms entries.
// This differs from setting the console channel to the same as the
// debug channel in that console output will go to the debug channel
// even if the debug channel is changed.
static cyg_uint8
cyg_hal_diag_mangler_null_getc(void* __ch_data)
{
    cyg_uint8 __ch;
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();
    CYGARC_HAL_SAVE_GP();

    __ch = CYGACC_COMM_IF_GETC(*__chan);

    CYGARC_HAL_RESTORE_GP();

    return __ch;
}


static void
cyg_hal_diag_mangler_null_putc(void* __ch_data, cyg_uint8 c)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();

    CYGARC_HAL_SAVE_GP();

    CYGACC_COMM_IF_PUTC(*__chan, c);

    CYGARC_HAL_RESTORE_GP();
}

static void
cyg_hal_diag_mangler_null_write(void* __ch_data,
                                const cyg_uint8* __buf, cyg_uint32 __len)
{
    CYGARC_HAL_SAVE_GP();

    while(__len-- > 0)
        cyg_hal_diag_mangler_null_putc(__ch_data, *__buf++);

    CYGARC_HAL_RESTORE_GP();
}

static void
cyg_hal_diag_mangler_null_read(void* __ch_data, 
                               cyg_uint8* __buf, cyg_uint32 __len)
{
    CYGARC_HAL_SAVE_GP();

    while(__len-- > 0)
        *__buf++ = cyg_hal_diag_mangler_null_getc(__ch_data);

    CYGARC_HAL_RESTORE_GP();
}

static int
cyg_hal_diag_mangler_null_control(void *__ch_data, 
                                  __comm_control_cmd_t __func, ...)
{
    // Do nothing (yet).
    return 0;
}

// This is the COMMS init function. It gets called both by the stubs
// and diag init code to initialize the COMMS mangler channel table -
// that's all. The callers have to decide whether to actually use this
// channel.
void
cyg_hal_diag_mangler_null_init(void)
{
    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_diag_mangler_null_write);
    CYGACC_COMM_IF_READ_SET(*comm, cyg_hal_diag_mangler_null_read);
    CYGACC_COMM_IF_PUTC_SET(*comm, cyg_hal_diag_mangler_null_putc);
    CYGACC_COMM_IF_GETC_SET(*comm, cyg_hal_diag_mangler_null_getc);
    CYGACC_COMM_IF_CONTROL_SET(*comm, cyg_hal_diag_mangler_null_control);
    
    // Restore the original console channel.
    CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);
}

//-----------------------------------------------------------------------------
// Console IO functions that adhere to the virtual vector table semantics in
// order to ensure proper debug agent mangling when required.
//
externC void cyg_hal_plf_comms_init(void);

void
hal_if_diag_init(void)
{
    // This function may be called from various places and the code
    // should only run once.
    static cyg_uint8 called = 0;
    if (called) return;
    called = 1;

#ifndef CYGSEM_HAL_VIRTUAL_VECTOR_INHERIT_CONSOLE

#if defined(CYGDBG_HAL_DIAG_TO_DEBUG_CHAN)
    // Use the mangler channel, which in turn uses the debug channel.
    CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_MANGLER);

    // Initialize the mangler channel.
#if defined(CYGSEM_HAL_DIAG_MANGLER_GDB)
    cyg_hal_diag_mangler_gdb_init();
#elif defined(CYGSEM_HAL_DIAG_MANGLER_None)
    cyg_hal_diag_mangler_null_init();
#endif

#else // CYGDBG_HAL_DIAG_TO_DEBUG_CHAN

    // Use an actual (raw) IO channel
    CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_HAL_VIRTUAL_VECTOR_CONSOLE_CHANNEL);

#endif // CYGDBG_HAL_DIAG_TO_DEBUG_CHAN

#endif // CYGSEM_HAL_VIRTUAL_VECTOR_INHERIT_CONSOLE
}

void 
hal_if_diag_write_char(char c)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_CONSOLE_PROCS();

    if (__chan)
        CYGACC_COMM_IF_PUTC(*__chan, c);
    else {
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();

        // FIXME: What should be done if assertions are not enabled?
        // This is a bad bad situation - we have no means for diag
        // output; we want to hit a breakpoint to alert the developer
        // or something like that.
        CYG_ASSERT(__chan, "No valid channel set");

        CYGACC_COMM_IF_PUTC(*__chan, c);
    }

    // Check interrupt flag
    if (CYGACC_CALL_IF_CONSOLE_INTERRUPT_FLAG()) {
        CYGACC_CALL_IF_CONSOLE_INTERRUPT_FLAG_SET(0);
        cyg_hal_user_break(0);
    }
}

void 
hal_if_diag_read_char(char *c)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
    
    if (__chan)
        *c = CYGACC_COMM_IF_GETC(*__chan);
    else {
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();

        // FIXME: What should be done if assertions are not enabled?
        // This is a bad bad situation - we have no means for diag
        // output; we want to hit a breakpoint to alert the developer
        // or something like that.
        CYG_ASSERT(__chan, "No valid channel set");

        *c = CYGACC_COMM_IF_GETC(*__chan);
    }
}
#endif // CYGSEM_HAL_VIRTUAL_VECTOR_DIAG

//=============================================================================
// CtrlC support
//=============================================================================

#if defined(CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT) \
    || defined(CYGDBG_HAL_DEBUG_GDB_CTRLC_SUPPORT)

struct Hal_SavedRegisters *hal_saved_interrupt_state;

void
hal_ctrlc_isr_init(void)
{
    // A ROM monitor never enables the interrupt itself. This is left
    // to the (RAM) application.
#ifndef CYGSEM_HAL_ROM_MONITOR
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();

#if 1 // Prevents crash on older stubs
    int v_m;
    // Allow only ctrl-c interrupt enabling when version in table is
    // below legal max and above the necessary service, and _not_
    // the value we set it to below.
    v_m = CYGACC_CALL_IF_VERSION() & CYGNUM_CALL_IF_TABLE_VERSION_CALL_MASK;
    if (v_m >= CYGNUM_CALL_IF_TABLE_VERSION_CALL_MAX 
        || v_m < CYGNUM_CALL_IF_SET_DEBUG_COMM
        || v_m == CYGNUM_CALL_IF_TABLE_VERSION_CALL_HACK)
        return;

    // Now trash that value - otherwise downloading an image with
    // builtin stubs on a board with older stubs (which will cause the
    // version to be set to VERSION_CALL) may cause all subsequent
    // runs to (wrongly) fall through to the below code.  If there is
    // a new stub on the board, it will reinitialize the version field
    // on reset.  Yes, this is a gross hack!
    CYGACC_CALL_IF_VERSION_SET(CYGNUM_CALL_IF_TABLE_VERSION_CALL_HACK);
#endif

    // We can only enable interrupts on a valid debug channel.
    if (__chan)
        CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_ENABLE);
#endif
}

cyg_uint32
hal_ctrlc_isr(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();
    int isr_ret = 0, ctrlc = 0;

    if (__chan) {
        isr_ret = CYGACC_COMM_IF_DBG_ISR(*__chan, &ctrlc, vector, data);
        if (ctrlc)
            cyg_hal_user_break( (CYG_ADDRWORD *)hal_saved_interrupt_state );
    }
    return isr_ret;
}

cyg_bool
hal_ctrlc_check(CYG_ADDRWORD vector, CYG_ADDRWORD data)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_DEBUG_PROCS();
    int gdb_vector = vector-1;
    int isr_ret, ctrlc = 0;

    // This check only to avoid crash on older stubs in case of unhandled
    // interrupts. It is a bit messy, but required in a transition period.
    if (__chan && 
        (CYGNUM_CALL_IF_TABLE_VERSION_CALL_HACK == 
         (CYGACC_CALL_IF_VERSION() & CYGNUM_CALL_IF_TABLE_VERSION_CALL_MASK))){
        gdb_vector = CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_DBG_ISR_VECTOR);
    }
    if (vector == gdb_vector) {
        isr_ret = CYGACC_COMM_IF_DBG_ISR(*__chan, &ctrlc, vector, data);
        if (ctrlc) {
            cyg_hal_user_break( (CYG_ADDRWORD *)hal_saved_interrupt_state );
            return true;
        }
    }
    return false;
}
#endif // CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT || CYGDBG_HAL_DEBUG_GDB_CTRLC_SUPPORT

//--------------------------------------------------------------------------
// Init function. It should be called from the platform initialization code.
// For monitor configurations it will initialize the calling interface table,
// for client configurations it will patch the existing table as per
// configuration.
void
hal_if_init(void)
{
    //**********************************************************************
    //
    // Note that if your RAM application is configured to initialize
    // the whole table _or_ the communication channels, you _cannot_
    // step through this function with the debugger. If your channel
    // configurations are set to the default, you should be able to
    // simply step over this function though (or use 'finish' once you
    // have entered this function if that GDB command works).
    // 
    // If you really do need to debug this code, the best approach is
    // to have a working RedBoot / GDB stub in ROM and then change the
    // hal_virtual_vector_table to reside at some other address in the
    // RAM configuration than that used by the ROM monitor.  Then
    // you'll be able to use the ROM monitor to debug the below code
    // and check that it does the right thing.
    //
    // Note that if you have a ROM monitor in ROM/flash which does
    // support virtual vectors, you should be able to disable the
    // option CYGSEM_HAL_VIRTUAL_VECTOR_INIT_WHOLE_TABLE. On some
    // targets (which predate the introduction of virtual vectors)
    // that option is enabled per default and needs to be explicitly
    // disabled when you have an updated ROM monitor.
    //
    //**********************************************************************

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_INIT_WHOLE_TABLE
    {
        int i;

        // Initialize tables with the NOP service.
        // This should only be done for service routine entries - data
        // pointers should be NULLed.
        for (i = 0; i < CYGNUM_CALL_IF_TABLE_SIZE; i++)
            hal_virtual_vector_table[i] = (CYG_ADDRWORD) &nop_service;
        
        // Version number
        CYGACC_CALL_IF_VERSION_SET(CYGNUM_CALL_IF_TABLE_VERSION_CALL
            |((CYG_ADDRWORD)CYGNUM_CALL_IF_TABLE_VERSION_COMM<<CYGNUM_CALL_IF_TABLE_VERSION_COMM_shift));
    }
#endif

    // Miscellaneous services with wrappers in this file.
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_RESET
    CYGACC_CALL_IF_RESET_SET(reset);
    CYGACC_CALL_IF_KILL_VECTOR_SET(kill_by_reset);
#endif
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_DELAY_US
    CYGACC_CALL_IF_DELAY_US_SET(delay_us);
#endif

#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_CACHE
    // Cache functions
    CYGACC_CALL_IF_FLUSH_ICACHE_SET(flush_icache);
    CYGACC_CALL_IF_FLUSH_DCACHE_SET(flush_dcache);
#endif

#ifdef CYGSEM_REDBOOT_FLASH_CONFIG
    CYGACC_CALL_IF_FLASH_CFG_OP_SET(flash_config_op);
#endif

    // Data entries not currently supported in eCos
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_DATA
    CYGACC_CALL_IF_DBG_DATA_SET(0);
#endif

    // Comm controls
#ifdef CYGSEM_HAL_VIRTUAL_VECTOR_CLAIM_COMMS
    {
        int i, j;

        // Clear out tables with safe dummy function.
        for (j = 0; j < CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS+1; j++)
            for (i = 0; i < CYGNUM_COMM_IF_TABLE_SIZE; i++)
                comm_channels[j][i] = (CYG_ADDRWORD) &nop_service;

        // Set accessor functions
        CYGACC_CALL_IF_SET_DEBUG_COMM_SET(set_debug_comm);
        CYGACC_CALL_IF_SET_CONSOLE_COMM_SET(set_console_comm);

        // Initialize console/debug procs. Note that these _must_
        // be set to empty before the comms init call.
        set_debug_comm(CYGNUM_CALL_IF_SET_COMM_ID_EMPTY);
        set_console_comm(CYGNUM_CALL_IF_SET_COMM_ID_EMPTY);

        // Initialize channels. This used to be done in
        // hal_diag_init() and the stub initHardware() functions, but
        // it makes more sense to have here.
        cyg_hal_plf_comms_init();

        // Always set the debug channel. If stubs are included, it is
        // necessary. If no stubs are included it does not hurt and is
        // likely to be required by the hal_if_diag_init code anyway
        // as it may rely on it if using a mangler.
        set_debug_comm(CYGNUM_HAL_VIRTUAL_VECTOR_DEBUG_CHANNEL);
        // Set console channel to a safe default. hal_if_diag_init
        // will override with console channel or mangler if necessary.
        set_console_comm(CYGNUM_HAL_VIRTUAL_VECTOR_DEBUG_CHANNEL);
    }

    // Reset console interrupt flag.
    CYGACC_CALL_IF_CONSOLE_INTERRUPT_FLAG_SET(0);
#endif

    // Set up services provided by clients
#if defined(CYGFUN_HAL_COMMON_KERNEL_SUPPORT)   &&  \
    ( defined(CYGSEM_HAL_USE_ROM_MONITOR_GDB_stubs) \
      || defined(CYGSEM_HAL_USE_ROM_MONITOR_CygMon))

    patch_dbg_syscalls( (void *)(hal_virtual_vector_table) );
#endif

    // Init client services
#if !defined(CYGPKG_KERNEL) && defined(CYGDBG_HAL_DEBUG_GDB_THREAD_SUPPORT)
    // Only include this code if we do not have a kernel. Otherwise
    // the kernel supplies the functionality for the app we are linked
    // with.

    // Prepare for application installation of thread info function in
    // vector table.
    init_thread_syscall( (void *)&hal_virtual_vector_table[CYGNUM_CALL_IF_DBG_SYSCALL] );
#endif

    // Finally, install async breakpoint handler if it is configured in.
    // FIXME: this should probably check for STUBS instead (but code is
    //        conditional on BREAK for now)
#if defined(CYGDBG_HAL_DEBUG_GDB_BREAK_SUPPORT)
    // Install async breakpoint handler into vector table.
    CYGACC_CALL_IF_INSTALL_BPT_FN_SET(&cyg_hal_gdb_interrupt);
#endif

#if 0 != CYGINT_HAL_PLF_IF_INIT
    // Call platform specific initializations - should only be used
    // to augment what has already been set up, etc.
    plf_if_init();
#endif
}
