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# ====================================================================
#
#      startup.cdl
#
#      ISO environment startup/termination related configuration data
#
# ====================================================================
## ####ECOSGPLCOPYRIGHTBEGIN####                                            
## -------------------------------------------                              
## This file is part of eCos, the Embedded Configurable Operating System.   
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## for more details.                                                        
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# ====================================================================
######DESCRIPTIONBEGIN####
#
# Author(s):      jlarmour
# Contributors:
# Date:           2000-04-14
#
#####DESCRIPTIONEND####
#
# ====================================================================

cdl_package CYGPKG_LIBC_STARTUP {
    display       "ISO environment startup/termination"
    description   "
            This package manages the control of the
            environment (in the general sense) that an
            application would require for full ISO C / POSIX
            compatibility, including a main() entry point
            supplied with arguments and an environment
            (as retrievable by the getenv() function).
            It also includes at the other end of things,
            what happens when main() returns or exit() is
            called."
    doc           ref/c-library-startup.html
    include_dir   cyg/libc/startup
    parent        CYGPKG_LIBC
    requires      CYGPKG_ISOINFRA
    requires      { CYGINT_LIBC_STARTUP_CONTEXT == 1 }
    implements    CYGINT_ISO_EXIT
    implements    CYGINT_ISO_MAIN_STARTUP
    implements    CYGINT_ISO_ENVIRON

    compile       _exit.cxx      abort.cxx      atexit.cxx     \
                  environ.cxx    exit.cxx       invokemain.cxx \
                  main.cxx       mainthread.cxx

    compile       -library=libextras.a cstartup.cxx

# ====================================================================

    cdl_interface CYGINT_LIBC_STARTUP_EXTERNAL_INVOKE_MAIN_POSSIBLE {
        display       "main() can be invoked elsewhere"
        description   "Implementors of this interface show that they
                       allow main() to be invoked elsewhere."
        flavor        bool
        no_define
    }

    cdl_option CYGDAT_LIBC_ARGUMENTS {
        display       "Arguments to main()"
        flavor        data
        default_value {"{(char *)\"\", (char *)NULL}"}
        description   "
            This option allows the setting of the arguments
            to the main function. This only has any effect
            when cyg_iso_c_start() is used to start the
            ISO C compatibility. This will automatically
            invoke main() in an ISO C compatible fashion.
            This option is in fact used as argv, and so is
            an n-tuple of string constants. The final
            entry must be NULL. Conventionally if argv\[0\]
            is supplied, it is used to inform the program
            of its name."
    }
    

    cdl_component CYGPKG_LIBC_STARTUP_CONTEXT {
        display       "Startup context for main()"
        flavor        none
        no_define
        description   "This component describes the options available for
                       what context main() is invoked in, such as in a thread
                       etc."

        cdl_interface CYGINT_LIBC_STARTUP_CONTEXT {
            display       "Startup context implementors"
            no_define
        }


        cdl_option    CYGSEM_LIBC_STARTUP_MAIN_INITCONTEXT {
            display       "Invoked from initialization context"
            description   "With this option selected, main() will be
                           called via cyg_user_start() (unless the program
                           overrides the default cyg_user_start()). This
                           means it is run in the context of the system
                           initialization code, without the eCos kernel
                           scheduler running, and using the startup stack.
                           This means that any functions that may require 
                           interactions with a running kernel will not
                           work (including libc functions, if configured
                           to be thread safe for example), so you should
                           restrict yourself to only calling fully
                           re-entrant functions from within main() in
                           this case."
            flavor        bool
            default_value { 0 == CYGPKG_KERNEL && 0 == 
                            CYGINT_LIBC_STARTUP_EXTERNAL_INVOKE_MAIN_POSSIBLE }
            implements    CYGINT_LIBC_STARTUP_CONTEXT
            implements    CYGINT_LIBC_STARTUP_MAIN_NO_STACK_SIZE
        }

        cdl_component CYGSEM_LIBC_STARTUP_MAIN_THREAD {
            display       "Invoked as eCos thread"
            requires      CYGPKG_KERNEL
            flavor        bool
            default_value { 0 != CYGPKG_KERNEL && 0 == \
                            CYGINT_LIBC_STARTUP_EXTERNAL_INVOKE_MAIN_POSSIBLE }
            implements    CYGINT_LIBC_STARTUP_CONTEXT
            description   "
                With this option selected, main() is invoked from an eCos
                thread."
        
            cdl_option CYGSEM_LIBC_MAIN_STACK_FROM_SYSTEM {
                display        "System provides stack for main()'s thread"
                description    "
                    This option controls whether the stack of
                    main()'s thread is provided by the application or
                    provided by the system. When disabled, the
                    application must declare a pointer variable
                    cyg_libc_main_stack which is a pointer to an
                    appropriately aligned region of memory. The
                    application must also declare a variable of
                    type `int' called cyg_libc_main_stack_size
                    which contains the size of the stack in bytes.
                    This must be a multiple of 8."
                flavor         bool
                default_value  1
            }

            cdl_option CYGNUM_LIBC_MAIN_THREAD_PRIORITY {
                display         "Priority of main()'s thread"
                description     "
                    This option is used to provide the thread
                    priority which main()'s thread runs at. Be
                    sure to check that this number is appropriate
                    for the kernel scheduler chosen. Different
                    kernel schedulers impose different restrictions
                    on the usable priorities."
                flavor          data
                legal_values    0 to 0x7fffffff
                default_value   10
            }
        }

        cdl_option    CYGSEM_LIBC_STARTUP_MAIN_OTHER {
            display       "Invoked elsewhere"
            description   "With this option selected, main() must be
                           invoked by a separate package, or by the user."
            flavor        bool
            default_value { 0 != \
                            CYGINT_LIBC_STARTUP_EXTERNAL_INVOKE_MAIN_POSSIBLE }
            requires      CYGINT_LIBC_STARTUP_EXTERNAL_INVOKE_MAIN_POSSIBLE
            implements    CYGINT_LIBC_STARTUP_CONTEXT
        }
    }
    
    cdl_interface CYGINT_LIBC_STARTUP_MAIN_NO_STACK_SIZE {
        display        "Don't allow main()'s stack size to be set"
        description    "This interface describes whether the stack size
                        value set in this package is supported by the
                        implementation that invokes main. If not, that
                        option is disabled."
        flavor         bool
        no_define
    }
        
    cdl_option CYGNUM_LIBC_MAIN_DEFAULT_STACK_SIZE {
        display        "main()'s default thread stack size"
        flavor         data
        legal_values   16 to 0x7fffffff
        default_value  8192
        active_if      !CYGINT_LIBC_STARTUP_MAIN_NO_STACK_SIZE
        description    "
            This option sets the size of the stack used
            in the context that invokes main(). For example,
            with an eCos kernel, when the cyg_iso_c_start()
            function is used to invoke the user-supplied
            main() function in an ISO C compatible fashion,
            a separate thread is created to call main().
            This option controls the size of that thread's
            stack, which is allocated in the BSS. It
            must be a multiple of 8. Note, a low number
            here may be overriden by the HAL if there is
            a minimum requirement to process interrupts
            etc. This option cannot be set if the implementation
            that invokes main() does not use it."
    }

    cdl_component CYGFUN_LIBC_ATEXIT {
        display        "Include atexit() function"
        flavor         bool
        default_value  1
        description    "
            This option enables the use of the atexit()
            function, and ensure that the atexit handlers
            are invoked from within exit() as defined in
            the ISO C standard."
    
        cdl_option CYGNUM_LIBC_ATEXIT_HANDLERS {
            display        "Number of functions atexit() supports"
            flavor         data
            legal_values   1 to 0x7fffffff
            default_value  32
            description    "
                This option sets the number of functions
                that atexit() has room for. In other words,
                the number of separate atexit() calls that
                can be made before calling exit() or returning
                from main() ( in an environment controlled by
                cyg_iso_c_start() ). For strict compliance
                with the ISO C standard this should be at
                least 32."
        }
    }
    
    cdl_option CYGSEM_LIBC_EXIT_CALLS_FFLUSH {
        display        "Make exit() call fflush()"
        requires       CYGINT_ISO_STDIO_FILEACCESS
        default_value  { 0 != CYGINT_ISO_STDIO_FILEACCESS }
        description    "
            This option will ensure that all output
            streams are flushed when exitting using
            exit() as prescribed by the ISO C standard."
    }
    
    cdl_option CYGSEM_LIBC_EXIT_STOPS_SYSTEM {
        display        "_exit() stops all threads"
        requires       CYGPKG_KERNEL
        default_value  0
        description    "
            If this option is enabled then _exit(),
            which is called from exit() which itself is
            called on return from main(), stops the eCos
            scheduler. For strict POSIX 1003.1
            compatibility this would be the normal
            behaviour. To allow the thread to simply
            exit, without affecting other threads, simply
            leave this option disabled. If there is no eCos
            scheduler, then _exit() simply loops
            irrespective of the setting of this option."
    }
    
    cdl_option CYGDAT_LIBC_DEFAULT_ENVIRONMENT {
        display       "Default environment"
        flavor        data
        default_value {"{ NULL }"}
        description   "
            This option allows the setting of the default
            contents of the environment. This is in fact
            the contents of the global environment pointer
            char **environ defined by POSIX 1003.1. Strings
            must be of the form NAME=VALUE, and the final
            entry must be NULL."
    }
    
    cdl_option CYGSEM_LIBC_INVOKE_DEFAULT_STATIC_CONSTRUCTORS {
        display        "Invoke default static constructors"
        requires       CYGSEM_HAL_STOP_CONSTRUCTORS_ON_FLAG
        requires       { CYGSEM_LIBC_STARTUP_MAIN_THREAD || \
                  (CYGSEM_LIBC_STARTUP_MAIN_OTHER && CYGPKG_POSIX_PTHREAD) }
        default_value  0
        description    "
            This option causes the C library to call
            static constructors with default priority
            from within the context of the main() thread,
            working with the co-operation of the HAL.
            This may be needed for environments that
            expect static constructors to be run in a
            thread context. Note that this uses an object
            with priority 65534. Therefore do not use
            priority 65534 for any other static objects
            with this option enabled."
    }
        
    
# ====================================================================

    cdl_component CYGPKG_LIBC_STARTUP_OPTIONS {
        display       "ISO environment startup/termination build options"
        flavor        none
        no_define
        description   "
            Package specific build options including control over
            compiler flags used only in building this package,
            and details of which tests are built."


        cdl_option CYGPKG_LIBC_STARTUP_CFLAGS_ADD {
            display       "Additional compiler flags"
            flavor        data
            no_define
            default_value { "" }
            description   "
                This option modifies the set of compiler flags for
                building this package. These flags are used in addition
                to the set of global flags."
        }

        cdl_option CYGPKG_LIBC_STARTUP_CFLAGS_REMOVE {
            display       "Suppressed compiler flags"
            flavor        data
            no_define
            default_value { "" }
            description   "
                This option modifies the set of compiler flags for
                building this package. These flags are removed from
                the set of global flags if present."
        }

        cdl_option CYGPKG_LIBC_STARTUP_TESTS {
            display       "ISO environment startup/termination tests"
            flavor        data
            no_define
            calculated    { "tests/atexit" }
            description   "
                This option specifies the set of tests for this package."
        }
    }
}

# ====================================================================
# EOF startup.cdl