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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.

## Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.

##

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## the terms of the GNU General Public License as published by the Free

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## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

## for more details.

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## 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

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## must still be made available in accordance with section (3) of the GNU

## General Public License v2.

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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