parse.c

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//==========================================================================
//
//      parse.c
//
//      RedBoot command line parsing routine
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
// Copyright (C) 2004, 2005, 2006 eCosCentric Limited
//
// 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.
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas
// Contributors: gthomas, eCosCentric
// Date:         2000-07-14
// Purpose:      
// Description:  
//              
// This code is part of RedBoot (tm).
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <redboot.h>
#include <cyg/hal/hal_arch.h>
#include <cyg/hal/hal_intr.h>
#include <cyg/hal/hal_cache.h>
#include CYGHWR_MEMORY_LAYOUT_H
#include <cyg/hal/hal_tables.h>

// Define table boundaries
extern struct cmd __RedBoot_CMD_TAB__[], __RedBoot_CMD_TAB_END__;

//
// Scan through an input line and break it into "arguments".  These
// are space delimited strings.  Return a structure which points to
// the strings, similar to a Unix program. Multiple commands in the line
// are separated by ; similar to sh. If we find a semi we stop processing the 
// line, terminate the current command with a null and return the start 
// of the next command in *line. parse() can then be called again to 
// process the next command on the line.
// Note: original input is destroyed by replacing the delimiters with 
// null ('\0') characters for ease of use.
//
struct cmd *
parse(char **line, int *argc, char **argv)
{
    char *cp = *line;
    char *pp;
    int indx = 0;
    int semi = 0;

    while (*cp) {
        // Skip leading spaces
        while (*cp && *cp == ' ') cp++;
        if (!*cp) {
            break;  // Line ended with a string of spaces
        }
	if (*cp == ';') {
            *cp = '\0';
            semi=1;
            break;
	}
        if (indx < MAX_ARGV) {
            argv[indx++] = cp;
        } else {
            diag_printf("Too many arguments - stopped at: '%s'\n", cp);
        }
        while (*cp) {
            if (*cp == ' ') {
                *cp++ = '\0';
                break;
            } else if (*cp == ';') {
                break;
	    } else if (*cp == '"') {
                // Swallow quote, scan till following one
                if (argv[indx-1] == cp) {
                    argv[indx-1] = ++cp;
                }
                pp = cp;
                while (*cp && *cp != '"') {
                    if (*cp == '\\') {
                        // Skip over escape - allows for escaped '"'
                        cp++;
                    }
                    // Move string to swallow escapes
                    *pp++ = *cp++;
                }
                if (!*cp) {
                    diag_printf("Unbalanced string!\n");
                } else {
                    if (pp != cp) *pp = '\0';
                    *cp++ = '\0';
                    break;
                }
            } else {
                cp++;
            }
        }
    }
    if (semi) {
        *line = cp + 1;
    } else {
        *line = cp;
    }
    *argc = indx;
    return cmd_search(__RedBoot_CMD_TAB__, &__RedBoot_CMD_TAB_END__, argv[0]);
}

//
// Search through a list of commands
//
struct cmd *
cmd_search(struct cmd *tab, struct cmd *tabend, char *arg)
{
    int cmd_len;
    struct cmd *cmd, *cmd2;
    // Search command table
    cmd_len = strlen(arg);
    cmd = tab;
    while (cmd != tabend) {
        if (strncasecmp(arg, cmd->str, cmd_len) == 0) {
            if (strlen(cmd->str) > cmd_len) {
                // Check for ambiguous commands here
                // Note: If there are commands which are not length-unique
                // then this check will be invalid.  E.g. "du" and "dump"
                bool first = true;
                cmd2 = tab;
                while (cmd2 != tabend) {
                    if ((cmd != cmd2) && 
                        (strncasecmp(arg, cmd2->str, cmd_len) == 0)) {
                        if (first) {
                            diag_printf("Ambiguous command '%s', choices are: %s", 
                                        arg, cmd->str);
                            first = false;
                        }
                        diag_printf(" %s", cmd2->str);
                    }
                    cmd2++;
                }
                if (!first) {
                    // At least one ambiguity found - fail the lookup
                    diag_printf("\n");
                    return (struct cmd *)0;
                }
            }
            return cmd;
        }
        cmd++;
    }
    return (struct cmd *)0;
}

void
cmd_usage(struct cmd *tab, struct cmd *tabend, char *prefix)
{
    struct cmd *cmd;

    diag_printf("Usage:\n"); 
    for (cmd = tab;  cmd != tabend;  cmd++) {
        diag_printf("  %s%s %s\n", prefix, cmd->str, cmd->usage);
    }
}

//
// Handle illegal memory accesses (and other abort conditions)
//
static hal_jmp_buf error_jmpbuf;
static cyg_bool redboot_exec_call = false;
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS
__externC void* volatile __mem_fault_handler;

static void error_handler(void)
{
    hal_longjmp(error_jmpbuf, 1);
}
#endif

// Routine to allow code to invoke RedBoot commands. This is useful
// during initialization and in platform specific code.
//
// Call it like this:
//
// result = redboot_exec( "load", "-m", "file", "foo", 0 );
//
// Note the terminating zero. The result will be zero if the command
// succeeded, and <0 if something went wrong.

#define ARGV_MAX        20
int redboot_exec( char *command, ... )
{
    int argc;
    char *argv[ARGV_MAX+1];
    va_list ap;
    struct cmd *cmd;
    int result = 0;
    
    va_start(ap, command);

    argv[0] = command;
    for( argc = 1; argc < ARGV_MAX; argc++ )
    {
        char *arg = va_arg(ap, char *);
        if( arg == 0 )
            break;
        argv[argc] = arg;
    }
    argv[argc] = NULL;

    if(( cmd = cmd_search(__RedBoot_CMD_TAB__, &__RedBoot_CMD_TAB_END__, command) ))
    {
        // Try to handle aborts - messy because of the stack unwinding...
#ifdef CYGDBG_HAL_DEBUG_GDB_INCLUDE_STUBS
        __mem_fault_handler = error_handler;
#endif
        redboot_exec_call = true;
        if (hal_setjmp(error_jmpbuf))