1 //=======================================================================
5 // Default main() function
7 //========================================================================
8 //####ECOSGPLCOPYRIGHTBEGIN####
9 // -------------------------------------------
10 // This file is part of eCos, the Embedded Configurable Operating System.
11 // Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
13 // eCos is free software; you can redistribute it and/or modify it under
14 // the terms of the GNU General Public License as published by the Free
15 // Software Foundation; either version 2 or (at your option) any later version.
17 // eCos is distributed in the hope that it will be useful, but WITHOUT ANY
18 // WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 // You should have received a copy of the GNU General Public License along
23 // with eCos; if not, write to the Free Software Foundation, Inc.,
24 // 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26 // As a special exception, if other files instantiate templates or use macros
27 // or inline functions from this file, or you compile this file and link it
28 // with other works to produce a work based on this file, this file does not
29 // by itself cause the resulting work to be covered by the GNU General Public
30 // License. However the source code for this file must still be made available
31 // in accordance with section (3) of the GNU General Public License.
33 // This exception does not invalidate any other reasons why a work based on
34 // this file might be covered by the GNU General Public License.
36 // Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
37 // at http://sources.redhat.com/ecos/ecos-license/
38 // -------------------------------------------
39 //####ECOSGPLCOPYRIGHTEND####
40 //========================================================================
41 //#####DESCRIPTIONBEGIN####
43 // Author(s): jlarmour
46 // Purpose: Provide a default empty main() function
47 // Description: This file provides a default empty main() function so
48 // that things don't fall apart if the user starts the
49 // ISO C environment (the default setting) but doesn't
50 // provide their own main(). This is taken advantage of
51 // in some tests (for example)
52 // Usage: Obviously simply override main() in your own program to
53 // prevent the use of the one below
55 //####DESCRIPTIONEND####
57 //========================================================================
61 #include <pkgconf/system.h> // for CYGPKG_KERNEL
65 #include <cyg/infra/cyg_type.h> // Common type definitions and support
66 #include <cyg/infra/cyg_trac.h> // Common tracing support
67 #include <cyg/infra/cyg_ass.h> // Common assertion support
70 # include <pkgconf/kernel.h> // kernel configuration
71 # include <cyg/kernel/thread.hxx> // For thread suspend
72 # include <cyg/kernel/thread.inl>
75 // FUNCTION PROTOTYPES
77 // We provide a weakly named main to allow this to link if the user
78 // doesn't provide their own main. This isn't strictly good behaviour,
79 // but if the user wants good performance then of _course_ they should
80 // play with the config options and this won't be called. Or it might
81 // be "giving them enough rope" etc. :-)
84 main( int argc, char *argv[] ) __attribute__((weak));
92 main( int argc, char *argv[] )
94 CYG_REPORT_FUNCNAMETYPE("main", "returning %d" );
96 // try to be helpful by diagnosing malformed arguments
97 CYG_PRECONDITION( argv != NULL, "argv is NULL!" );
98 CYG_PRECONDITION( argv[argc] == NULL, "argv[argc] isn't NULL!" );
100 CYG_REPORT_FUNCARG2("argc=%d, argv[0]=%s", argc,
101 (CYG_ADDRWORD)((argv[0]==NULL) ? "NULL" : argv[0]) );
103 CYG_TRACE0( true, "This is the system-supplied default main()" );
105 // If the kernel isn't present then cyg_libc_invoke_main() will have assumed
106 // main() is present and will call it. But if we're here, then
107 // evidently the user didn't supply one - which can't be right. So we
108 // assume that they have useful code to run in cyg_user_start() instead.
109 // Its better than just exiting
110 #ifndef CYGPKG_KERNEL
113 // Otherwise we suspend ourselves. This prevents problems caused by
114 // running atexit() handlers.
115 Cyg_Thread::self()->suspend();
118 CYG_REPORT_RETVAL(0);
119 return 0; // some CPUs have 0 hard-wired - faster than a reg