Subversion Repositories openrisc

//==========================================================================
//
//      io.c
//
//      RedBoot I/O support
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 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):    gthomas
// Contributors: gthomas,hmt,jlarmour
// Date:         2000-07-14
// Purpose:      
// Description:  
//              
// This code is part of RedBoot (tm).
//
//####DESCRIPTIONEND####
//
//==========================================================================
 
#include "redboot.h"
 
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS
// GDB interface functions
extern void ungetDebugChar(char c);
#endif
 
static void
do_channel(int argc, char *argv[]);
 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
RedBoot_cmd("channel", 
            "Display/switch console channel", 
            "[-1|<channel number>]",
            do_channel
    );
#else
RedBoot_cmd("channel", 
            "Display/switch console channel", 
            "[<channel number>]",
            do_channel
    );
#endif
 
static void
do_channel(int argc, char *argv[])
{
    int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
 
    if (argc == 2) { 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
        if (strcmp( argv[1], "-1") == 0) {
            console_selected = false;
            console_echo = true;
        } else 
#endif
        {
            unsigned long chan;
            if ( !parse_num( argv[1], &chan, NULL, NULL) ) {
                diag_printf("** Error: invalid channel '%s'\n", argv[1]);
            } else {
                if (chan < CYGNUM_HAL_VIRTUAL_VECTOR_NUM_CHANNELS) {
                    CYGACC_CALL_IF_SET_CONSOLE_COMM(chan);
                    CYGACC_CALL_IF_SET_DEBUG_COMM(chan);
                    if (chan != cur)
                        console_echo = true;
                }
                else {
                    diag_printf("**Error: bad channel number '%s'\n", argv[1]);
                }
            }
        }
    }
    /* else display */ 
    else {
        diag_printf("Current console channel id: ");
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
        if (!console_selected)
            diag_printf("-1\n");
        else
#endif
            diag_printf("%d\n", cur);
    }
}
 
void 
mon_write_char(unsigned char c)
{
    hal_virtual_comm_table_t *__chan;
 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
    if (!console_selected) {
        int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
        int i;
        // Send output to all channels
        for (i = 0;  i < CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS;  i++) {
            CYGACC_CALL_IF_SET_CONSOLE_COMM(i);
            __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
            CYGACC_COMM_IF_PUTC(*__chan, c);
        }
        CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);
    } else 
#endif
    {
        __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
        if (__chan)
            CYGACC_COMM_IF_PUTC(*__chan, c);
        else {
            __chan = CYGACC_CALL_IF_DEBUG_PROCS();
            CYGACC_COMM_IF_PUTC(*__chan, c);
        }
    }
}
 
static void 
mon_read_char(unsigned 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();
        *c = CYGACC_COMM_IF_GETC(*__chan);
    }
}
 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
static int _mon_timeout;
#endif
 
bool
mon_read_char_with_timeout(unsigned char *c)
{
    bool res = false;
    hal_virtual_comm_table_t *__chan;
 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
    if (!console_selected) {
        int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
        int i, j, tot;
        // Try input from all channels
        tot = 0;
        while (tot < _mon_timeout) {
            for (i = 0;  i < CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS;  i++, tot++) {
                CYGACC_CALL_IF_SET_CONSOLE_COMM(i);
                __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
                res = CYGACC_COMM_IF_GETC_TIMEOUT(*__chan, c);
                if (res) {
                    // Input available on this channel, make it be the console
                    if (*c != '\0') {
                        // Don't chose this unless real data have arrived
                        console_selected = true;
                        CYGACC_CALL_IF_SET_DEBUG_COMM(i);
                        // Disable interrupts on all channels but this one
                        for (j = 0;  j < CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS;  j++) {
                            if (i != j) {
                                CYGACC_CALL_IF_SET_CONSOLE_COMM(j);
                                __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
                                CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_IRQ_DISABLE);
                            }
                        }
                        CYGACC_CALL_IF_SET_CONSOLE_COMM(i);
                        return res;
                    }
                }
            }
        }
        CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);        
    } else 
#endif
    {
        __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
        if (__chan)
            res = CYGACC_COMM_IF_GETC_TIMEOUT(*__chan, c);
        else {
            __chan = CYGACC_CALL_IF_DEBUG_PROCS();
            res = CYGACC_COMM_IF_GETC_TIMEOUT(*__chan, c);
        }
    }
    return res;
}
 
void
mon_set_read_char_timeout(int ms)
{
    hal_virtual_comm_table_t *__chan;
 
#ifdef CYGPKG_REDBOOT_ANY_CONSOLE
    if (!console_selected) {
        int cur = CYGACC_CALL_IF_SET_CONSOLE_COMM(CYGNUM_CALL_IF_SET_COMM_ID_QUERY_CURRENT);
        int i;
        // Set timeout to minimum on each channel; total amounts to desired value
        _mon_timeout = ms;
        ms = 1;
        for (i = 0;  i < CYGNUM_HAL_VIRTUAL_VECTOR_COMM_CHANNELS;  i++) {
            CYGACC_CALL_IF_SET_CONSOLE_COMM(i);
            if ((__chan = CYGACC_CALL_IF_CONSOLE_PROCS()) != 0) {
                CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_SET_TIMEOUT, ms);
            }
        }
        CYGACC_CALL_IF_SET_CONSOLE_COMM(cur);        
    } else 
#endif
    {
        if ((__chan = CYGACC_CALL_IF_CONSOLE_PROCS()) != 0) {
            CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_SET_TIMEOUT, ms);
        }
        if ((__chan = CYGACC_CALL_IF_DEBUG_PROCS()) != 0) {
            CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_SET_TIMEOUT, ms);
        }
    }
}
 
//
// Test for ^C on the console.  CAUTION! discards all console input
//
bool
_rb_break(int timeout)
{
    unsigned char c;
    mon_set_read_char_timeout(timeout);
    if (mon_read_char_with_timeout(&c)) {
        if (c == '\x03') {  // Test for ^C
            return true;
        }
    }
    return false;
}
 
#ifdef CYGFUN_REDBOOT_BOOT_SCRIPT
#define __STRINGIFY(x) #x
#define _STRINGIFY(x) __STRINGIFY(x)
#define _STARTUP_STR _STRINGIFY(CYG_HAL_STARTUP) "}"
 
//
// Read a character from script.
// Return true if script character found, false if not.
//
static int
getc_script(char *cp)
{
    static bool newline = true;
    bool skip;
 
    while (script && *script) {
	if (newline && *script == '{') {
	    skip = false;
	    ++script;
 
	    // skip if it isn't for this startup type
	    if (strncmp(script, _STARTUP_STR, strlen(_STARTUP_STR)))
		skip = true;
 
	    // skip past "{...}"
	    while (*script && *script++ != '}')
		;
 
	    // skip script line if neccessary
	    if (skip) {
		while (*script && *script++ != '\n')
		    ;
	    } else
		newline = false;
 
	} else {
	    *cp = *script++;
	    if (*cp == '\n') {
              newline = true;
            } else {
              newline = false;
            }
	    return true;
	}
    }
    return false;
}
#endif
 
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
#define _CL_NUM_LINES CYGNUM_REDBOOT_CMD_LINE_EDITING       // Number of lines to keep
static char _cl_lines[_CL_NUM_LINES][CYGPKG_REDBOOT_MAX_CMD_LINE];
static int  _cl_index = -1;      // Last known command line
static int  _cl_max_index = -1;  // Last command in buffers
static int  _cl_real_index = 0;  // Virtual command index (0..N)
 
#ifdef CYGBLD_REDBOOT_CMD_LINE_HISTORY
static void expand_history(char *);
#endif
#endif
 
//
// Read a line of input from the user
// Return:
//        _GETS_OK: 'n' valid characters received
//       _GETS_GDB: '$' (GDB lead-in)
//   _GETS_TIMEOUT: No input before timeout
//     _GETS_CTRLC: ^C typed
//
// if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
//   Command line history support
//    ^P - Select previous line from history
//    ^N - Select next line from history
//    ^A - Move insertion [cursor] to start of line
//    ^E - Move cursor to end of line
//    ^B - Move cursor back [previous character]
//    ^F - Move cursor forward [next character]
// "standard" arrow keys work as well
//   left  ^[[D      == ^B
//   right ^[[C      == ^F
//   up    ^[[A      == ^P
//   down  ^[[B      == ^N
//   home  ^[[H/^[1~ == ^A
//   end   ^[[F/^[OF == ^E
//   del   ^[3~      == ^D
//
int
_rb_gets_preloaded(char *buf, int buflen, int timeout)
{
    char *ip = buf;   // Insertion point
    char *eol = buf;  // End of line
    char c;
    bool res = false;
    static char last_ch = '\0';
    int _timeout;
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
    int   _index = _cl_index;  // Last saved line
    char *xp;
#ifdef CYGSEM_REDBOOT_CMD_LINE_ANSI_SEQUENCES
    int   ansi_state = 0;      // Used to drive ANSI parser
    char  ansi_char = '\0';
#endif
#endif
 
    // Display current buffer data
    while (*eol) {
        mon_write_char(*eol++);
    }
    ip = eol;
 
    while (true) {
#ifdef CYGFUN_REDBOOT_BOOT_SCRIPT
        if (getc_script(&c))
            do_idle(false);
        else
#endif
        if ((timeout > 0) && (eol == buf)) {
#define MIN_TIMEOUT 50
            _timeout = timeout > MIN_TIMEOUT ? MIN_TIMEOUT : timeout;
            mon_set_read_char_timeout(_timeout);
            while (timeout > 0) {
                res = mon_read_char_with_timeout(&c);
                if (res) {
                    // Got a character
                    do_idle(false);
                    break;
                }
                timeout -= _timeout;
            }
            if (res == false) {
                do_idle(true);
                return _GETS_TIMEOUT;  // Input timed out
            }
        } else {
            mon_read_char(&c);
        }
        *eol = '\0';
#define CTRL(c) ((c)&0x1F)
#ifdef CYGSEM_REDBOOT_CMD_LINE_ANSI_SEQUENCES
        // Special handling of ANSI keyboard sequences (arrows, etc)
        if (c == '\x1B') {
            // Leadin for ANSI keyboard sequence
            ansi_state = 1;
            continue;
        }
        switch (ansi_state) {
        case 0:
            // No ANSI sequence in progress
            break;
        case 1:
            // ESC seen, look for '['
            if (c == '[') {
                ansi_state = 2;
            } else if (c == 'O') {
                ansi_state = 4;
            } else {
                // Handle bad sequences?
                ansi_state = 0;
            }
            continue;
        case 2:
            // ESC+[ seen, process key
            ansi_state = 0;
            switch (c) {
            case 'A':
                c = CTRL('P');
                break;
            case 'B':
                c = CTRL('N');
                break;
            case 'C':
                c = CTRL('F');
                break;
            case 'D':
                c = CTRL('B');
                break;
            case 'F':
                c = CTRL('E');
                break;
            case 'H':
                c = CTRL('A');
                break;
            case '1':
                ansi_char = CTRL('A');
                ansi_state = 3;
                continue;
            case '3':
                ansi_char = CTRL('D');
                ansi_state = 3;
                continue;
            default:
                // Handle bad sequences?
                continue;
            }
            break;
        case 3:
            // Sequences like ^[[1~ == ^H
            ansi_state = 0;
            if (c == '~') {
                c = ansi_char;
            } else {
                // Handle bad sequences?
                continue;
            }
            break;
        case 4:
            // Sequences like ^[OF == ^E
            ansi_state = 0;
            if (c == 'F') {
                c = CTRL('E');
            } else {
                // Handle bad sequences?
                continue;
            }
            break;
        }
#endif
        switch (c) {
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
        case CTRL('P'):
            // Fetch the previous line into the buffer
            if (_index >= 0) {
                // Erase the previous line [crude]
                while (ip != buf) {
                    mon_write_char('\b');
                    mon_write_char(' ');
                    mon_write_char('\b');
                    ip--;
                }
                strcpy(buf, _cl_lines[_index]);
                while (*ip) {
                    mon_write_char(*ip++);
                }
                eol = ip;
                // Move to previous line
                _index--;
                if (_index < 0) {
                    _index = _cl_max_index;
                }
            } else {
                mon_write_char(0x07);  // Audible bell on most devices
            }
            break;
        case CTRL('N'):
            // Fetch the next line into the buffer
            if (_index >= 0) {
                if (++_index > _cl_max_index) _index = 0;
                // Erase the previous line [crude]
                while (ip != buf) {
                    mon_write_char('\b');
                    mon_write_char(' ');
                    mon_write_char('\b');
                    ip--;
                }
                strcpy(buf, _cl_lines[_index]);
                while (*ip) {
                    mon_write_char(*ip++);
                }
                eol = ip;
            } else {
                mon_write_char(0x07);  // Audible bell on most devices
            }
            break;
        case CTRL('B'): 
            // Move insertion point backwards
            if (ip != buf) {
                mon_write_char('\b');
                ip--;
            }
            break;
        case CTRL('F'):
            // Move insertion point forwards
            if (ip != eol) {
                mon_write_char(*ip++);
            }
            break;
        case CTRL('E'):
            // Move insertion point to end of line
            while (ip != eol) {
                mon_write_char(*ip++);
            }
            break;
        case CTRL('A'):
            // Move insertion point to beginning of line
            if (ip != buf) {
                xp = ip;
                while (xp-- != buf) {
                    mon_write_char('\b');
                }
            }
            ip = buf;
            break;
        case CTRL('K'):
            // Kill to the end of line
            if (ip != eol) {
                xp = ip;
                while (xp++ != eol) {
                    mon_write_char(' ');
                }
                while (--xp != ip) {
                    mon_write_char('\b');
                }
                eol = ip;
            }
            break;
        case CTRL('D'):
            // Erase the character under the cursor
            if (ip != eol) {
                xp = ip;
                eol--;
                while (xp != eol) {
                    *xp = *(xp+1);
                    mon_write_char(*xp++);
                }
                mon_write_char(' ');  // Erases last character
                mon_write_char('\b');
                while (xp-- != ip) {
                    mon_write_char('\b');
                }
            }
            break;
#endif // CYGNUM_REDBOOT_CMD_LINE_EDITING
        case CTRL('C'): // ^C
            // Abort current input
            diag_printf("^C\n");
            *buf = '\0';  // Nothing useful in buffer
            return _GETS_CTRLC;
        case '\n':
        case '\r':
            // If previous character was the "other" end-of-line, ignore this one
            if (((c == '\n') && (last_ch == '\r')) ||
                ((c == '\r') && (last_ch == '\n'))) {
                c = '\0';
                break;
            }
            // End of line
	    if (console_echo) {
                mon_write_char('\r');
                mon_write_char('\n');
	    }
            last_ch = c;
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
            if (cmd_history) {
                // History handling - only when enabled
#ifdef CYGBLD_REDBOOT_CMD_LINE_HISTORY
		expand_history(buf);
#endif
		if (*buf != '\0') {
		    if (++_cl_index == _CL_NUM_LINES) {
                        _cl_index = 0;
                    }
		    if (_cl_index > _cl_max_index) _cl_max_index = _cl_index;
		    strcpy(_cl_lines[_cl_index], buf);
                    _cl_real_index++;
		}
            }
#endif
            return _GETS_OK;
        case '\b':
        case 0x7F:  // DEL
            if (ip != buf) {
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
                if (ip != eol) {
                    ip--;
                    mon_write_char('\b');
                    xp = ip;
                    while (xp != (eol-1)) {
                        *xp = *(xp+1);
                        mon_write_char(*xp++);
                    }
                    mon_write_char(' ');  // Erases last character
                    mon_write_char('\b');
                    while (xp-- != ip) {
                        mon_write_char('\b');
                    }
                } else {
                    if (console_echo) {
                        mon_write_char('\b');
                        mon_write_char(' ');
                        mon_write_char('\b');
                    }
                    ip--;
                }
                eol--;
#else
                if (console_echo) {
                    mon_write_char('\b');
                    mon_write_char(' ');
                    mon_write_char('\b');
                }
                ip--;
                eol--;
#endif
            }
            break;
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS
        case '+': // fall through
        case '$':
            if (ip == buf || last_ch != '\\')
            {
                // Give up and try GDB protocol
                ungetDebugChar(c);  // Push back character so stubs will see it
                return _GETS_GDB;
            }
            if (last_ch == '\\') {
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
                if (ip == eol) {
                    // Just save \$ as $
                    eol = --ip;
                } else {
                    mon_write_char('\b');
                    *--ip = c;
                    mon_write_char(c);
                    break;
                }
#else
                ip--;  // Save \$ as $
#endif
            }
            // else fall through
#endif
        default:
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
            // If the insertion point is not at the end of line, make space for it
            if (ip != eol) {
                xp = eol;
                *++eol = '\0';
                while (xp != ip) {
                    *xp = *(xp-1);
                    xp--;
                }
            }
#endif
            if (console_echo) {
                mon_write_char((unsigned char)c);
            }
            if (ip == eol) {
                // Advance both pointers
                *ip++ = c;
                eol = ip;
#if CYGNUM_REDBOOT_CMD_LINE_EDITING != 0
            } else {
                // Just insert the character
                *ip++ = c;
                xp = ip;
                while (xp != eol) {
                    mon_write_char(*xp++);
                }
                while (xp-- != ip) {
                    mon_write_char('\b');
                }
#endif
            }
        }
        last_ch = c;
        if (ip == buf + buflen - 1) { // Buffer full
            *ip = '\0';
            return buflen;
        }
    }
}
 
int
_rb_gets(char *buf, int buflen, int timeout)
{
    *buf = '\0';  // Empty buffer
    return _rb_gets_preloaded(buf, buflen, timeout);
}
 
static bool
_verify_action(int timeout, char *fmt, va_list ap)
{
    char ans[8];
    int ret;
#ifdef CYGFUN_REDBOOT_BOOT_SCRIPT
    // Don't ask if we're executing a script
    if (script && *script)
        return 1;
#endif
 
    diag_vprintf(fmt, ap);
    diag_printf(" - continue (y/n)? ");
    if ((ret = _rb_gets(ans, sizeof(ans), timeout)) > 0) {
        return ((ans[0] == 'y') || (ans[0] == 'Y'));
    } else {
        if (ret == _GETS_TIMEOUT) {
            diag_printf(" ** Timed out!\n");
        }
        return 0;  // Timed out or ^C
    }
}
 
bool
verify_action(char *fmt, ...)
{
    va_list ap;
 
    va_start(ap, fmt);
    return _verify_action(0, fmt, ap);
}
 
bool
verify_action_with_timeout(int timeout, char *fmt, ...)
{
    va_list ap;
 
    va_start(ap, fmt);
    return _verify_action(timeout, fmt, ap);
}
 
 
#ifdef CYGBLD_REDBOOT_CMD_LINE_HISTORY
// parse for history index number. Return number or -1 if not
// an index number.
static int
parse_history_index(char *s)
{
    int val = 0;
 
    while ('0' <= *s && *s <= '9')
	val = (val * 10) + (*s++ - '0');
 
    if (*s)
	return -1;
 
    return val;
}
 
// Check input line to see if it needs history expansion. If so,
// try to find matching command and replace buffer as appropriate.
static void
expand_history(char *buf)
{
    int ncmds = _cl_max_index + 1;
    int i, index, len;
 
    if (buf[0] != '!' || buf[1] == '\0')
	return;
 
    if (ncmds > 0) {
	if (!strcmp(buf, "!!")) {
	    strcpy(buf, _cl_lines[_cl_index]);
	    return;
	}
	if ((index = parse_history_index(buf + 1)) >= 0) {
            if (index <= _cl_real_index) {
                while (index >= _CL_NUM_LINES) {
                    index -= _CL_NUM_LINES;
                }
                strcpy(buf, _cl_lines[index]);
                return;
            }
	} else {
            len = strlen(buf + 1);
            for (i = 0, index = _cl_index; i < ncmds; i++) {
                if (!strncmp(_cl_lines[index], buf+1, len)) {
                    strcpy(buf, _cl_lines[index]);
                    return;
                }
                if (--index < 0)
                    index = _cl_max_index;
            }
        }
    }
 
    diag_printf("%s: event not found\n", buf);
    *buf = '\0';
}
 
static void
do_history(int argc, char *argv[])
{
    int ncmds = _cl_max_index + 1;
    int i, index;
 
    if (_cl_index == _cl_max_index) {
	// history has not wrapped around
	for (i = 0; i < ncmds; i++)
	    diag_printf("%3d %s\n", i, _cl_lines[i]);
    } else {
        diag_printf("_cl_index = %d\n", _cl_index);
	for (i = 0, index = _cl_index + 1; i < ncmds; i++) {
	    diag_printf("%3d %s\n", i+_cl_real_index-_CL_NUM_LINES, _cl_lines[index++]);
	    if (index > _cl_max_index)
		index = 0;
	}
    }
}
 
RedBoot_cmd("history", 
            "Display command history", 
            "",
            do_history
    );
#endif  // CYGBLD_REDBOOT_CMD_LINE_HISTORY