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

//

//      alias.c

//

//      RedBoot - alias support

//

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

//####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):    gthomas

// Contributors: gthomas, jskov

// Date:         2002-05-15

// Purpose:      

// Description:  

//              

// This code is part of RedBoot (tm).

//

//####DESCRIPTIONEND####

//

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

#include <redboot.h>

#ifdef CYGNUM_REDBOOT_FLASH_STRING_SIZE

# define MAX_STRING_LENGTH CYGNUM_REDBOOT_FLASH_STRING_SIZE

#else

# define MAX_STRING_LENGTH 32

#endif

// Lookup an alias. First try plain string aliases. If that fails try

// other types so allowing access to all configured values. This allows

// for alias (macro) expansion of normal 'fconfig' data, such as the

// board IP address.

static char *

lookup_alias(char *alias, char *alias_buf)

{

    if (0 == strcasecmp("FREEMEMLO", alias)) {

        diag_sprintf(alias_buf,"%p", ((CYG_ADDRWORD)user_ram_start + 0x03ff) & ~0x03ff);

        return alias_buf;

    } else if (0 == strcasecmp("FREEMEMHI", alias)) {

        diag_sprintf(alias_buf,"%p", ((CYG_ADDRWORD)user_ram_end) & ~0x03ff);

        return alias_buf;

    }

#ifdef CYGSEM_REDBOOT_FLASH_ALIASES

    return flash_lookup_alias(alias, alias_buf);

#else

    return NULL;

#endif

}

// Expand aliases, this is recursive. ie if one alias contains other

// aliases, these will also be expanded from the insertion point

// onwards.

//

// If 'iter' is zero, then quoted strings are not expanded

//

static bool

_expand_aliases(char *line, int len, int iter)

{

    char *lp = line;

    char *ms, *me, *ep;

    char *alias;

    char c;

    int offset, line_len, alias_len;

    char alias_buf[MAX_STRING_LENGTH];

    bool macro_found = false;

    if ((line_len = strlen(line)) != 0) {

        while (*lp) {

            c = *lp++;

            if ((c == '%') && (*lp == '{')) {

                // Found a macro/alias to expand

                ms = lp+1;

                lp += 2;

                while (*lp && (*lp != '}')) lp++;

                if (!*lp) {

                    diag_printf("Invalid macro/alias '%s'\n", ms);

                    line[0] = '\0';  // Destroy line

                    return false;

                }

                me = lp;

                *me = '\0';

                lp++;

                if ((alias = lookup_alias(ms,alias_buf)) != (char *)NULL) {

                    alias_len = strlen(alias);

                    // See if there is room in the line to expand this macro/alias

                    if ((line_len+alias_len) < len) {

                        // Make a hole by moving data within the line

                        offset = alias_len-strlen(ms)-2;  // Number of bytes being inserted

                        ep = &lp[strlen(lp)-1];

                        if (offset > 1) {

                            ep[offset] = '\0';

                            while (ep != (lp-1)) {

                                ep[offset-1] = *ep;

                                ep--;

                            }

                        } else {

                            if (offset <=0) {

                                while ((lp-1) != ep) {

                                    lp[offset-1] = *lp;

                                    lp++;

                                }

                                lp[offset-1]='\0';

                            }

                        }

                        // Insert the macro/alias data

                        lp = ms-2;

                        while (*alias) {

                            if ((alias[0] == '%') && (alias[1] == '{')) macro_found = true;

                            *lp++ = *alias++;

                        }

                        line_len = strlen(line);

                        lp = lp - alias_len;

                    } else {

                        diag_printf("No room to expand '%s'\n", ms);

                        line[0] = '\0';  // Destroy line

                        return false;

                    }

                } else {

                    diag_printf("Alias '%s' not defined\n", ms);

                    *me = '|';

                }

            } else if ((c == '"') && (iter == 0)) {

                // Skip quoted strings

                while (*lp && (*lp != '"')) lp++;

            }

        }

    }

    return macro_found;

}

void

expand_aliases(char *line, int len)

{

    int iter = 0;

    while (_expand_aliases(line, len, iter++)) {

    }

}