libc.h

ecos为实时嵌入式操作系统

        }

        cdl_option CYGIMP_LIBC_RAND_SIMPLEST {
            display      "Simplest implementation"
            description  "This provides a very simple implementation of rand()
                          that does not perform well with randomness in the
                          lower significant bits. However it is exceptionally
                          fast. It uses the sample algorithm from the ISO C
                          standard itself."
            type         radio
            parent       CYGPKG_LIBC_RAND
        }

        cdl_option CYGIMP_LIBC_RAND_SIMPLE1 {
            display      "Simple implementation #1"
            description  "This provides a very simple implementation of rand()
                          based on the simplest implementation above. However
                          it does try to work around the lack of randomness
                          in the lower significant bits, at the expense of a
                          little speed."
            type         radio
            parent       CYGPKG_LIBC_RAND
        }

        cdl_option CYGIMP_LIBC_RAND_KNUTH1 {
            display      "Knuth implementation #1"
            description  "This implements a slightly more complex algorithm
                          published in Donald E. Knuth's Art of Computer
                          Programming Vol.2 section 3.6 (p.185 in the 3rd ed.).
                          This produces better random numbers than the
                          simplest approach but is slower."
            type         radio
            parent       CYGPKG_LIBC_RAND
        }

        cdl_component CYGPKG_LIBC_MALLOC {
            display      "Support for dynamic memory allocation"
            description  "This enables support for dynamic memory
                          allocation as supplied by the functions malloc(),
                          free(), calloc() and realloc(). As these
                          functions are often used, but can have quite an
                          overhead, disabling them here can ensure they
                          cannot even be used accidentally when static
                          allocation is preferred."
            type         boolean
            parent       CYGPKG_LIBC_STDLIB
            requires     CYGPKG_KERNEL
        }

        cdl_option CYGNUM_LIBC_MALLOC_MEMPOOL_SIZE {
            display      "Size of the dynamic memory pool in bytes"
            description  "At this stage, dynamic memory allocation by
                          malloc() and calloc() must be from a fixed-size,
                          contiguous memory pool (note here that it is the
                          pool that is of a fixed size, but malloc() is still
                          able to allocate variable sized chunks of memory
                          from it). This option is the size
                          of that pool, in bytes. Note that not all of
                          this is available for programs to
                          use - some is needed for internal information
                          about memory regions, and some may be lost to
                          ensure that memory allocation only returns
                          memory aligned on word (or double word)
                          boundaries - a very common architecture
                          constraint."
            type         count
            legal_values 32 to 0x7fffffff
            parent       CYGPKG_LIBC_MALLOC
        }

        cdl_option CYGIMP_LIBC_MALLOC_CXX_DELETE_CALLS_FREE {
            display      "Support for C++ delete operator"
            description  "C++ new and delete operators can call
                          the C library's malloc() and free() implicitly.
                          If this is what is required, enable this option.
                          However, if enabled, the dynamic memory allocation 
                          code is always linked in to the application,
                          even if it is not explicitly called and new/delete
                          are not used.
                          This increases code and data size needlessly."
            type         bool
            parent       CYGPKG_LIBC_MALLOC
        }

        cdl_option CYGFUN_LIBC_strtod {
            display      "Provides strtod() and atof()"
            description  "This option allows use of the utility function
                          strtod() (and consequently atof()) to convert
                          from string to double precision floating point
                          numbers. Disabling this option removes the
                          dependency on the math library package."
            type         boolean
            parent       CYGPKG_LIBC_STDLIB
            requires     CYGPKG_LIBM
        }

        cdl_option CYGNUM_LIBC_BSEARCH_TRACE_LEVEL {
            display      "bsearch() tracing level"
            description  "Trace verbosity level for debugging the <stdlib.h>
                          binary search function bsearch(). Increase this
                          value to get additional trace output."
            type         count
            legal_values 0 to 1
            parent       CYGPKG_LIBC_STDLIB
        }

        cdl_option CYGNUM_LIBC_QSORT_TRACE_LEVEL {
            display      "qsort() tracing level"
            description  "Trace verbosity level for debugging the <stdlib.h>
                          quicksort function qsort(). Increase this value
                          to get additional trace output."
            type         count
            legal_values 0 to 1
            parent       CYGPKG_LIBC_STDLIB
        }

    }}CFG_DATA
*/

#define CYGIMP_LIBC_STDLIB_INLINES

#undef CYGSEM_LIBC_PER_THREAD_RAND

#define CYGNUM_LIBC_RAND_SEED 1

#define CYGNUM_LIBC_RAND_TRACE_LEVEL 0

#undef CYGIMP_LIBC_RAND_SIMPLEST

#define CYGIMP_LIBC_RAND_SIMPLE1

#undef CYGIMP_LIBC_RAND_KNUTH1

#define CYGPKG_LIBC_MALLOC

#ifdef CYGPKG_LIBC_MALLOC

#undef CYGIMP_LIBC_MALLOC_CXX_DELETE_CALLS_FREE

#define CYGNUM_LIBC_MALLOC_MEMPOOL_SIZE 16384

#endif // ifdef CYGPKG_LIBC_MALLOC

#define CYGFUN_LIBC_strtod

#define CYGNUM_LIBC_BSEARCH_TRACE_LEVEL 0

#define CYGNUM_LIBC_QSORT_TRACE_LEVEL 0

#ifdef CYGFUN_LIBC_strtod
# ifndef CYGPKG_LIBM
#  error You must enable the Math library package to use strtod() or atof()
# endif
#endif

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

// STDIO CONFIGURATION OPTIONS

/*
    {{CFG_DATA
        cdl_component CYGPKG_LIBC_STDIO {
            display      "Standard Input/Output functions"
            description  "This enables support for standard I/O functions
                          from <stdio.h>."
            type         boolean
            parent       CYGPKG_LIBC
            requires     CYGPKG_IO
            requires     CYGPKG_IO_SERIAL_HALDIAG
        }

        cdl_option CYGIMP_LIBC_STDIO_INLINES {
            display      "Inline versions of <stdio.h> functions"
            description  "This option chooses whether some of the
                          particularly simple functions from
                          <stdio.h> are available as inline
                          functions. This may improve performance, and as
                          the functions are small, may even improve code
                          size."
            type         boolean
            parent       CYGPKG_LIBC_STDIO
        }

        cdl_option FOPEN_MAX {
            display      "Permitted number of open files"
            description  "This option controls the guaranteed minimum
                          number of simultaneously open files. The ISO
                          C standard requires it to be defined (para
                          7.9.1), and if strictly compliant, it must be
                          at least 8 (para 7.9.3). In practice it can be
                          as low as 3 - for stdin, stdout and stderr."
            type         count
            legal_values 3 to 0x7fffffff
            parent       CYGPKG_LIBC_STDIO
        }

        cdl_option FILENAME_MAX {
            display      "Maximum length of filename"
            description  "This option defines the maximum allowed size of
                          a filename in characters. The ISO C standard
                          requires it to be defined (para 7.9.1)."
            type         count
            legal_values 1 to 0x7fffffff
            parent       CYGPKG_LIBC_STDIO
        }

        cdl_option L_tmpnam {
            display      "Maximum length of filenames for temporary files"
            description  "This option defines the maximum allowed size of
                          filenames for temporary files as generated by
                          tmpnam(). It is measured in characters, and the
                          ISO C standard requires it to be defined (para 
                          7.9.1)."
            type         count
            legal_values 1 to 0x7fffffff
            parent       CYGPKG_LIBC_STDIO
        }

        cdl_option TMP_MAX {
            display       "Unique file names generated by tmpnam()"
            description   "This option defines the minimum number of
                           unique file names generated by tmpnam(). The
                           ISO C standard requires it to be defined (para
                           7.9.1)."
            type          count
            legal_values  0 to 0x7fffffff
            parent        CYGPKG_LIBC_STDIO
        }

        cdl_component CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO {
            display       "Buffered I/O"
            description   "This option controls whether input/output
                           through the <stdio.h> functions is buffered.
                           This may save some memory per file. It
                           is equivalent to putting every file into
                           non-buffered mode (_IONBF) through setvbuf(),
                           except now it can never be altered back to
                           buffered mode. Disabling buffering is strictly 
                           non-compliant with the ISO C standard."
            type          boolean
            parent        CYGPKG_LIBC_STDIO
        }

        cdl_option CYGNUM_LIBC_STDIO_BUFSIZE {
            display        "Default buffer size"
            description    "This option defines the default size of buffer
                            used with calls to setbuf(), and is the default
                            size for buffered streams that have not had
                            either setbuf() or setvbuf() invoked on them.
                            It is exactly equivalent to the standard
                            constant BUFSIZ, except that it is 0 if
                            CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO is disabled.
                            The ISO C standard requires this to be defined
                            (para 7.9.1), and says it must be at least 256
                            (para 7.9.2)."
            type           count
            legal_values   1 to 0x7fffffff
            parent         CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO
        }

        cdl_option CYGSEM_LIBC_STDIO_DYNAMIC_SETVBUF {
            display        "setbuf()/setvbuf() uses malloc()"
            description    "This option controls whether I/O buffers are
                            implemented dynamically within the stdio
                            implementation. Otherwise they will be static,
                            and cannot be changed by setbuf()/setvbuf(). If
                            they are static (i.e. this option is disabled),
                            any attempt to use an arbitrary buffer size, or
                            to pass a user-supplied buffer to setbuf() or
                            setvbuf() will fail - the buffer is implemented
                            internally as a static array of taking the size
                            of the configuration option BUFSIZ. The only
                            exception is if a user buffer is not supplied,
                            and the buffer size requested is less than
                            BUFSIZ. In this case, the buffer will
                            be configured to only use that amount of
                            buffering. However the unused memory left over
                            will NOT be freed. If this option is enabled,
                            then CYGPKG_LIBC_MALLOC must also
                            be enabled. Either setting can be considered to
                            be compliant with the ISO C standard."
            type           boolean
            parent         CYGSEM_LIBC_STDIO_WANT_BUFFERED_IO
            requires       CYGPKG_LIBC_MALLOC
        }

        cdl_option CYGFUN_LIBC_STDIO_ungetc {
            display         "Support for ungetc()"
            description     "This option controls whether ungetc() is
                             supported. If not, then some space can be
                             saved, and speed is improved. Note that you
                             MUST have this defined if you want to use the
                             scanf() family of functions."
            type            boolean
            parent          CYGPKG_LIBC_STDIO
        }

        cdl_option CYGPKG_LIBC_STDIO_OPEN {
            display         "Dynamic opening/closing of files"
            description     "fopen() and fclose() use dynamic memory