mbed library sources. Supersedes mbed-src. RTC working even after reset

Fork of mbed-dev by mbed official

Revision:
144:ef7eb2e8f9f7
Parent:
85:4b017b08d507
Child:
147:30b64687e01f
--- a/common/retarget.cpp	Tue Aug 02 14:07:36 2016 +0000
+++ b/common/retarget.cpp	Fri Sep 02 15:07:44 2016 +0100
@@ -1,568 +1,759 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2015 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#include "platform.h"
-#include "FileHandle.h"
-#include "FileSystemLike.h"
-#include "FilePath.h"
-#include "serial_api.h"
-#include "toolchain.h"
-#include "semihost_api.h"
-#include "mbed_interface.h"
-#if DEVICE_STDIO_MESSAGES
-#include <stdio.h>
-#endif
-#include <errno.h>
-
-#if defined(__ARMCC_VERSION)
-#   include <rt_sys.h>
-#   define PREFIX(x)    _sys##x
-#   define OPEN_MAX     _SYS_OPEN
-#   ifdef __MICROLIB
-#       pragma import(__use_full_stdio)
-#   endif
-
-#elif defined(__ICCARM__)
-#   include <yfuns.h>
-#   define PREFIX(x)        _##x
-#   define OPEN_MAX         16
-
-#   define STDIN_FILENO     0
-#   define STDOUT_FILENO    1
-#   define STDERR_FILENO    2
-
-#else
-#   include <sys/stat.h>
-#   include <sys/unistd.h>
-#   include <sys/syslimits.h>
-#   define PREFIX(x)    x
-#endif
-
-using namespace mbed;
-
-#if defined(__MICROLIB) && (__ARMCC_VERSION>5030000)
-// Before version 5.03, we were using a patched version of microlib with proper names
-extern const char __stdin_name[]  = ":tt";
-extern const char __stdout_name[] = ":tt";
-extern const char __stderr_name[] = ":tt";
-
-#else
-extern const char __stdin_name[]  = "/stdin";
-extern const char __stdout_name[] = "/stdout";
-extern const char __stderr_name[] = "/stderr";
-#endif
-
-/* newlib has the filehandle field in the FILE struct as a short, so
- * we can't just return a Filehandle* from _open and instead have to
- * put it in a filehandles array and return the index into that array
- * (or rather index+3, as filehandles 0-2 are stdin/out/err).
- */
-static FileHandle *filehandles[OPEN_MAX];
-
-FileHandle::~FileHandle() {
-    /* Remove all open filehandles for this */
-    for (unsigned int fh_i = 0; fh_i < sizeof(filehandles)/sizeof(*filehandles); fh_i++) {
-        if (filehandles[fh_i] == this) {
-            filehandles[fh_i] = NULL;
-        }
-    }
-}
-
-#if DEVICE_SERIAL
-extern int stdio_uart_inited;
-extern serial_t stdio_uart;
-#endif
-
-static void init_serial() {
-#if DEVICE_SERIAL
-    if (stdio_uart_inited) return;
-    serial_init(&stdio_uart, STDIO_UART_TX, STDIO_UART_RX);
-#endif
-}
-
-static inline int openmode_to_posix(int openmode) {
-    int posix = openmode;
-#ifdef __ARMCC_VERSION
-    if (openmode & OPEN_PLUS) {
-        posix = O_RDWR;
-    } else if(openmode & OPEN_W) {
-        posix = O_WRONLY;
-    } else if(openmode & OPEN_A) {
-        posix = O_WRONLY|O_APPEND;
-    } else {
-        posix = O_RDONLY;
-    }
-    /* a, w, a+, w+ all create if file does not already exist */
-    if (openmode & (OPEN_A|OPEN_W)) {
-        posix |= O_CREAT;
-    }
-    /* w and w+ truncate */
-    if (openmode & OPEN_W) {
-        posix |= O_TRUNC;
-    }
-#elif defined(__ICCARM__)
-    switch (openmode & _LLIO_RDWRMASK) {
-        case _LLIO_RDONLY: posix = O_RDONLY; break;
-        case _LLIO_WRONLY: posix = O_WRONLY; break;
-        case _LLIO_RDWR  : posix = O_RDWR  ; break;
-    }
-    if (openmode & _LLIO_CREAT ) posix |= O_CREAT;
-    if (openmode & _LLIO_APPEND) posix |= O_APPEND;
-    if (openmode & _LLIO_TRUNC ) posix |= O_TRUNC;
-#elif defined(TOOLCHAIN_GCC)
-    posix &= ~O_BINARY;
-#endif
-    return posix;
-}
-
-extern "C" FILEHANDLE PREFIX(_open)(const char* name, int openmode) {
-    #if defined(__MICROLIB) && (__ARMCC_VERSION>5030000)
-    // Before version 5.03, we were using a patched version of microlib with proper names
-    // This is the workaround that the microlib author suggested us
-    static int n = 0;
-    if (!std::strcmp(name, ":tt")) return n++;
-
-    #else
-    /* Use the posix convention that stdin,out,err are filehandles 0,1,2.
-     */
-    if (std::strcmp(name, __stdin_name) == 0) {
-        init_serial();
-        return 0;
-    } else if (std::strcmp(name, __stdout_name) == 0) {
-        init_serial();
-        return 1;
-    } else if (std::strcmp(name, __stderr_name) == 0) {
-        init_serial();
-        return 2;
-    }
-    #endif
-
-    // find the first empty slot in filehandles
-    unsigned int fh_i;
-    for (fh_i = 0; fh_i < sizeof(filehandles)/sizeof(*filehandles); fh_i++) {
-        if (filehandles[fh_i] == NULL) break;
-    }
-    if (fh_i >= sizeof(filehandles)/sizeof(*filehandles)) {
-        return -1;
-    }
-
-    FileHandle *res;
-
-    /* FILENAME: ":0x12345678" describes a FileLike* */
-    if (name[0] == ':') {
-        void *p;
-        sscanf(name, ":%p", &p);
-        res = (FileHandle*)p;
-
-    /* FILENAME: "/file_system/file_name" */
-    } else {
-        FilePath path(name);
-
-        if (!path.exists())
-            return -1;
-        else if (path.isFile()) {
-            res = path.file();
-        } else {
-            FileSystemLike *fs = path.fileSystem();
-            if (fs == NULL) return -1;
-            int posix_mode = openmode_to_posix(openmode);
-            res = fs->open(path.fileName(), posix_mode); /* NULL if fails */
-        }
-    }
-
-    if (res == NULL) return -1;
-    filehandles[fh_i] = res;
-
-    return fh_i + 3; // +3 as filehandles 0-2 are stdin/out/err
-}
-
-extern "C" int PREFIX(_close)(FILEHANDLE fh) {
-    if (fh < 3) return 0;
-
-    FileHandle* fhc = filehandles[fh-3];
-    filehandles[fh-3] = NULL;
-    if (fhc == NULL) return -1;
-
-    return fhc->close();
-}
-
-#if defined(__ICCARM__)
-extern "C" size_t    __write (int        fh, const unsigned char *buffer, size_t length) {
-#else
-extern "C" int PREFIX(_write)(FILEHANDLE fh, const unsigned char *buffer, unsigned int length, int mode) {
-#endif
-    int n; // n is the number of bytes written
-    if (fh < 3) {
-#if DEVICE_SERIAL
-        if (!stdio_uart_inited) init_serial();
-        for (unsigned int i = 0; i < length; i++) {
-            serial_putc(&stdio_uart, buffer[i]);
-        }
-#endif
-        n = length;
-    } else {
-        FileHandle* fhc = filehandles[fh-3];
-        if (fhc == NULL) return -1;
-
-        n = fhc->write(buffer, length);
-    }
-#ifdef __ARMCC_VERSION
-    return length-n;
-#else
-    return n;
-#endif
-}
-
-#if defined(__ICCARM__)
-extern "C" size_t    __read (int        fh, unsigned char *buffer, size_t       length) {
-#else
-extern "C" int PREFIX(_read)(FILEHANDLE fh, unsigned char *buffer, unsigned int length, int mode) {
-#endif
-    int n; // n is the number of bytes read
-    if (fh < 3) {
-        // only read a character at a time from stdin
-#if DEVICE_SERIAL
-        if (!stdio_uart_inited) init_serial();
-        *buffer = serial_getc(&stdio_uart);
-#endif
-        n = 1;
-    } else {
-        FileHandle* fhc = filehandles[fh-3];
-        if (fhc == NULL) return -1;
-
-        n = fhc->read(buffer, length);
-    }
-#ifdef __ARMCC_VERSION
-    return length-n;
-#else
-    return n;
-#endif
-}
-
-#ifdef __ARMCC_VERSION
-extern "C" int PREFIX(_istty)(FILEHANDLE fh)
-#else
-extern "C" int _isatty(FILEHANDLE fh)
-#endif
-{
-    /* stdin, stdout and stderr should be tty */
-    if (fh < 3) return 1;
-
-    FileHandle* fhc = filehandles[fh-3];
-    if (fhc == NULL) return -1;
-
-    return fhc->isatty();
-}
-
-extern "C"
-#if defined(__ARMCC_VERSION)
-int _sys_seek(FILEHANDLE fh, long position)
-#elif defined(__ICCARM__)
-long __lseek(int fh, long offset, int whence)
-#else
-int _lseek(FILEHANDLE fh, int offset, int whence)
-#endif
-{
-    if (fh < 3) return 0;
-
-    FileHandle* fhc = filehandles[fh-3];
-    if (fhc == NULL) return -1;
-
-#if defined(__ARMCC_VERSION)
-    return fhc->lseek(position, SEEK_SET);
-#else
-    return fhc->lseek(offset, whence);
-#endif
-}
-
-#ifdef __ARMCC_VERSION
-extern "C" int PREFIX(_ensure)(FILEHANDLE fh) {
-    if (fh < 3) return 0;
-
-    FileHandle* fhc = filehandles[fh-3];
-    if (fhc == NULL) return -1;
-
-    return fhc->fsync();
-}
-
-extern "C" long PREFIX(_flen)(FILEHANDLE fh) {
-    if (fh < 3) return 0;
-
-    FileHandle* fhc = filehandles[fh-3];
-    if (fhc == NULL) return -1;
-
-    return fhc->flen();
-}
-#endif
-
-
-#if !defined(__ARMCC_VERSION) && !defined(__ICCARM__)
-extern "C" int _fstat(int fd, struct stat *st) {
-    if ((STDOUT_FILENO == fd) || (STDERR_FILENO == fd) || (STDIN_FILENO == fd)) {
-        st->st_mode = S_IFCHR;
-        return  0;
-    }
-
-    errno = EBADF;
-    return -1;
-}
-#endif
-
-namespace std {
-extern "C" int remove(const char *path) {
-    FilePath fp(path);
-    FileSystemLike *fs = fp.fileSystem();
-    if (fs == NULL) return -1;
-
-    return fs->remove(fp.fileName());
-}
-
-extern "C" int rename(const char *oldname, const char *newname) {
-    FilePath fpOld(oldname);
-    FilePath fpNew(newname);
-    FileSystemLike *fsOld = fpOld.fileSystem();
-    FileSystemLike *fsNew = fpNew.fileSystem();
-
-    /* rename only if both files are on the same FS */
-    if (fsOld != fsNew || fsOld == NULL) return -1;
-
-    return fsOld->rename(fpOld.fileName(), fpNew.fileName());
-}
-
-extern "C" char *tmpnam(char *s) {
-    return NULL;
-}
-
-extern "C" FILE *tmpfile() {
-    return NULL;
-}
-} // namespace std
-
-#ifdef __ARMCC_VERSION
-extern "C" char *_sys_command_string(char *cmd, int len) {
-    return NULL;
-}
-#endif
-
-extern "C" DIR *opendir(const char *path) {
-    /* root dir is FileSystemLike */
-    if (path[0] == '/' && path[1] == 0) {
-        return FileSystemLike::opendir();
-    }
-
-    FilePath fp(path);
-    FileSystemLike* fs = fp.fileSystem();
-    if (fs == NULL) return NULL;
-
-    return fs->opendir(fp.fileName());
-}
-
-extern "C" struct dirent *readdir(DIR *dir) {
-    return dir->readdir();
-}
-
-extern "C" int closedir(DIR *dir) {
-    return dir->closedir();
-}
-
-extern "C" void rewinddir(DIR *dir) {
-    dir->rewinddir();
-}
-
-extern "C" off_t telldir(DIR *dir) {
-    return dir->telldir();
-}
-
-extern "C" void seekdir(DIR *dir, off_t off) {
-    dir->seekdir(off);
-}
-
-extern "C" int mkdir(const char *path, mode_t mode) {
-    FilePath fp(path);
-    FileSystemLike *fs = fp.fileSystem();
-    if (fs == NULL) return -1;
-
-    return fs->mkdir(fp.fileName(), mode);
-}
-
-#if defined(TOOLCHAIN_GCC)
-/* prevents the exception handling name demangling code getting pulled in */
-#include "mbed_error.h"
-namespace __gnu_cxx {
-    void __verbose_terminate_handler() {
-        error("Exception");
-    }
-}
-extern "C" WEAK void __cxa_pure_virtual(void);
-extern "C" WEAK void __cxa_pure_virtual(void) {
-    exit(1);
-}
-
-#endif
-
-// ****************************************************************************
-// mbed_main is a function that is called before main()
-// mbed_sdk_init() is also a function that is called before main(), but unlike
-// mbed_main(), it is not meant for user code, but for the SDK itself to perform
-// initializations before main() is called.
-
-extern "C" WEAK void mbed_main(void);
-extern "C" WEAK void mbed_main(void) {
-}
-
-extern "C" WEAK void mbed_sdk_init(void);
-extern "C" WEAK void mbed_sdk_init(void) {
-}
-
-#if defined(TOOLCHAIN_ARM)
-extern "C" int $Super$$main(void);
-
-extern "C" int $Sub$$main(void) {
-    mbed_sdk_init();
-    mbed_main();
-    return $Super$$main();
-}
-#elif defined(TOOLCHAIN_GCC)
-extern "C" int __real_main(void);
-
-extern "C" int __wrap_main(void) {
-    mbed_sdk_init();
-    mbed_main();
-    return __real_main();
-}
-#elif defined(TOOLCHAIN_IAR)
-// IAR doesn't have the $Super/$Sub mechanism of armcc, nor something equivalent
-// to ld's --wrap. It does have a --redirect, but that doesn't help, since redirecting
-// 'main' to another symbol looses the original 'main' symbol. However, its startup
-// code will call a function to setup argc and argv (__iar_argc_argv) if it is defined.
-// Since mbed doesn't use argc/argv, we use this function to call our mbed_main.
-extern "C" void __iar_argc_argv() {
-    mbed_sdk_init();
-    mbed_main();
-}
-#endif
-
-// Provide implementation of _sbrk (low-level dynamic memory allocation
-// routine) for GCC_ARM which compares new heap pointer with MSP instead of
-// SP.  This make it compatible with RTX RTOS thread stacks.
-#if defined(TOOLCHAIN_GCC_ARM)
-// Linker defined symbol used by _sbrk to indicate where heap should start.
-extern "C" int __end__;
-
-#if defined(TARGET_CORTEX_A)
-extern "C" uint32_t  __HeapLimit;
-#endif
-
-// Turn off the errno macro and use actual global variable instead.
-#undef errno
-extern "C" int errno;
-
-// For ARM7 only
-register unsigned char * stack_ptr __asm ("sp");
-
-// Dynamic memory allocation related syscall.
-extern "C" caddr_t _sbrk(int incr) {
-    static unsigned char* heap = (unsigned char*)&__end__;
-    unsigned char*        prev_heap = heap;
-    unsigned char*        new_heap = heap + incr;
-
-#if defined(TARGET_ARM7)
-    if (new_heap >= stack_ptr) {
-#elif defined(TARGET_CORTEX_A)
-    if (new_heap >= (unsigned char*)&__HeapLimit) {     /* __HeapLimit is end of heap section */
-#else
-    if (new_heap >= (unsigned char*)__get_MSP()) {
-#endif
-        errno = ENOMEM;
-        return (caddr_t)-1;
-    }
-
-    heap = new_heap;
-    return (caddr_t) prev_heap;
-}
-#endif
-
-
-#if defined TOOLCHAIN_GCC_ARM
-extern "C" void _exit(int return_code) {
-#else
-namespace std {
-extern "C" void exit(int return_code) {
-#endif
-
-#if DEVICE_STDIO_MESSAGES
-    fflush(stdout);
-    fflush(stderr);
-#endif
-
-#if DEVICE_SEMIHOST
-    if (mbed_interface_connected()) {
-        semihost_exit();
-    }
-#endif
-    if (return_code) {
-        mbed_die();
-    }
-
-    while (1);
-}
-
-#if !defined(TOOLCHAIN_GCC_ARM)
-} //namespace std
-#endif
-
-
-namespace mbed {
-
-void mbed_set_unbuffered_stream(FILE *_file) {
-#if defined (__ICCARM__)
-    char buf[2];
-    std::setvbuf(_file,buf,_IONBF,NULL);    
-#else
-    setbuf(_file, NULL);
-#endif
-}
-
-int mbed_getc(FILE *_file){
-#if defined (__ICCARM__)
-    /*This is only valid for unbuffered streams*/
-    int res = std::fgetc(_file);
-    if (res>=0){
-        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
-        _file->_Rend = _file->_Wend;
-        _file->_Next = _file->_Wend;
-    }    
-    return res;
-#else    
-    return std::fgetc(_file);
-#endif   
-}
-
-char* mbed_gets(char*s, int size, FILE *_file){
-#if defined (__ICCARM__)
-    /*This is only valid for unbuffered streams*/
-    char *str = fgets(s,size,_file);
-    if (str!=NULL){
-        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
-        _file->_Rend = _file->_Wend;
-        _file->_Next = _file->_Wend;
-    }
-    return str;
-#else    
-    return std::fgets(s,size,_file);
-#endif
-}
-
-} // namespace mbed
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2015 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "platform.h"
+#include "FileHandle.h"
+#include "FileSystemLike.h"
+#include "FilePath.h"
+#include "serial_api.h"
+#include "toolchain.h"
+#include "semihost_api.h"
+#include "mbed_interface.h"
+#include "SingletonPtr.h"
+#include "PlatformMutex.h"
+#include "mbed_error.h"
+#include <stdlib.h>
+#if DEVICE_STDIO_MESSAGES
+#include <stdio.h>
+#endif
+#include <errno.h>
+
+#if defined(__ARMCC_VERSION)
+#   include <rt_sys.h>
+#   define PREFIX(x)    _sys##x
+#   define OPEN_MAX     _SYS_OPEN
+#   ifdef __MICROLIB
+#       pragma import(__use_full_stdio)
+#   endif
+
+#elif defined(__ICCARM__)
+#   include <yfuns.h>
+#   define PREFIX(x)        _##x
+#   define OPEN_MAX         16
+
+#   define STDIN_FILENO     0
+#   define STDOUT_FILENO    1
+#   define STDERR_FILENO    2
+
+#else
+#   include <sys/stat.h>
+#   include <sys/unistd.h>
+#   include <sys/syslimits.h>
+#   define PREFIX(x)    x
+#endif
+
+#define FILE_HANDLE_RESERVED    0xFFFFFFFF
+
+using namespace mbed;
+
+#if defined(__MICROLIB) && (__ARMCC_VERSION>5030000)
+// Before version 5.03, we were using a patched version of microlib with proper names
+extern const char __stdin_name[]  = ":tt";
+extern const char __stdout_name[] = ":tt";
+extern const char __stderr_name[] = ":tt";
+
+#else
+extern const char __stdin_name[]  = "/stdin";
+extern const char __stdout_name[] = "/stdout";
+extern const char __stderr_name[] = "/stderr";
+#endif
+
+// Heap limits - only used if set
+unsigned char *mbed_heap_start = 0;
+uint32_t mbed_heap_size = 0;
+
+/* newlib has the filehandle field in the FILE struct as a short, so
+ * we can't just return a Filehandle* from _open and instead have to
+ * put it in a filehandles array and return the index into that array
+ * (or rather index+3, as filehandles 0-2 are stdin/out/err).
+ */
+static FileHandle *filehandles[OPEN_MAX];
+static SingletonPtr<PlatformMutex> filehandle_mutex;
+
+FileHandle::~FileHandle() {
+    filehandle_mutex->lock();
+    /* Remove all open filehandles for this */
+    for (unsigned int fh_i = 0; fh_i < sizeof(filehandles)/sizeof(*filehandles); fh_i++) {
+        if (filehandles[fh_i] == this) {
+            filehandles[fh_i] = NULL;
+        }
+    }
+    filehandle_mutex->unlock();
+}
+
+#if DEVICE_SERIAL
+extern int stdio_uart_inited;
+extern serial_t stdio_uart;
+#if MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
+static char stdio_in_prev;
+static char stdio_out_prev;
+#endif
+#endif
+
+static void init_serial() {
+#if DEVICE_SERIAL
+    if (stdio_uart_inited) return;
+    serial_init(&stdio_uart, STDIO_UART_TX, STDIO_UART_RX);
+#if MBED_CONF_CORE_STDIO_BAUD_RATE
+    serial_baud(&stdio_uart, MBED_CONF_CORE_STDIO_BAUD_RATE);
+#endif
+#endif
+}
+
+static inline int openmode_to_posix(int openmode) {
+    int posix = openmode;
+#ifdef __ARMCC_VERSION
+    if (openmode & OPEN_PLUS) {
+        posix = O_RDWR;
+    } else if(openmode & OPEN_W) {
+        posix = O_WRONLY;
+    } else if(openmode & OPEN_A) {
+        posix = O_WRONLY|O_APPEND;
+    } else {
+        posix = O_RDONLY;
+    }
+    /* a, w, a+, w+ all create if file does not already exist */
+    if (openmode & (OPEN_A|OPEN_W)) {
+        posix |= O_CREAT;
+    }
+    /* w and w+ truncate */
+    if (openmode & OPEN_W) {
+        posix |= O_TRUNC;
+    }
+#elif defined(__ICCARM__)
+    switch (openmode & _LLIO_RDWRMASK) {
+        case _LLIO_RDONLY: posix = O_RDONLY; break;
+        case _LLIO_WRONLY: posix = O_WRONLY; break;
+        case _LLIO_RDWR  : posix = O_RDWR  ; break;
+    }
+    if (openmode & _LLIO_CREAT ) posix |= O_CREAT;
+    if (openmode & _LLIO_APPEND) posix |= O_APPEND;
+    if (openmode & _LLIO_TRUNC ) posix |= O_TRUNC;
+#elif defined(TOOLCHAIN_GCC)
+    posix &= ~O_BINARY;
+#endif
+    return posix;
+}
+
+extern "C" FILEHANDLE PREFIX(_open)(const char* name, int openmode) {
+    #if defined(__MICROLIB) && (__ARMCC_VERSION>5030000)
+    // Before version 5.03, we were using a patched version of microlib with proper names
+    // This is the workaround that the microlib author suggested us
+    static int n = 0;
+    if (!std::strcmp(name, ":tt")) return n++;
+
+    #else
+    /* Use the posix convention that stdin,out,err are filehandles 0,1,2.
+     */
+    if (std::strcmp(name, __stdin_name) == 0) {
+        init_serial();
+        return 0;
+    } else if (std::strcmp(name, __stdout_name) == 0) {
+        init_serial();
+        return 1;
+    } else if (std::strcmp(name, __stderr_name) == 0) {
+        init_serial();
+        return 2;
+    }
+    #endif
+
+    // find the first empty slot in filehandles
+    filehandle_mutex->lock();
+    unsigned int fh_i;
+    for (fh_i = 0; fh_i < sizeof(filehandles)/sizeof(*filehandles); fh_i++) {
+        if (filehandles[fh_i] == NULL) break;
+    }
+    if (fh_i >= sizeof(filehandles)/sizeof(*filehandles)) {
+        filehandle_mutex->unlock();
+        return -1;
+    }
+    filehandles[fh_i] = (FileHandle*)FILE_HANDLE_RESERVED;
+    filehandle_mutex->unlock();
+
+    FileHandle *res;
+
+    /* FILENAME: ":0x12345678" describes a FileLike* */
+    if (name[0] == ':') {
+        void *p;
+        sscanf(name, ":%p", &p);
+        res = (FileHandle*)p;
+
+    /* FILENAME: "/file_system/file_name" */
+    } else {
+        FilePath path(name);
+
+        if (!path.exists()) {
+            // Free file handle
+            filehandles[fh_i] = NULL;
+            return -1;
+        } else if (path.isFile()) {
+            res = path.file();
+        } else {
+            FileSystemLike *fs = path.fileSystem();
+            if (fs == NULL) {
+                // Free file handle
+                filehandles[fh_i] = NULL;
+                return -1;
+            }
+            int posix_mode = openmode_to_posix(openmode);
+            res = fs->open(path.fileName(), posix_mode); /* NULL if fails */
+        }
+    }
+
+    if (res == NULL) {
+        // Free file handle
+        filehandles[fh_i] = NULL;
+        return -1;
+    }
+    filehandles[fh_i] = res;
+
+    return fh_i + 3; // +3 as filehandles 0-2 are stdin/out/err
+}
+
+extern "C" int PREFIX(_close)(FILEHANDLE fh) {
+    if (fh < 3) return 0;
+
+    FileHandle* fhc = filehandles[fh-3];
+    filehandles[fh-3] = NULL;
+    if (fhc == NULL) return -1;
+
+    return fhc->close();
+}
+
+#if defined(__ICCARM__)
+extern "C" size_t    __write (int        fh, const unsigned char *buffer, size_t length) {
+#else
+extern "C" int PREFIX(_write)(FILEHANDLE fh, const unsigned char *buffer, unsigned int length, int mode) {
+#endif
+    int n; // n is the number of bytes written
+    if (fh < 3) {
+#if DEVICE_SERIAL
+        if (!stdio_uart_inited) init_serial();
+#if MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
+        for (unsigned int i = 0; i < length; i++) {
+            if (buffer[i] == '\n' && stdio_out_prev != '\r') {
+                 serial_putc(&stdio_uart, '\r');
+            }
+            serial_putc(&stdio_uart, buffer[i]);
+            stdio_out_prev = buffer[i];
+        }
+#else
+        for (unsigned int i = 0; i < length; i++) {
+            serial_putc(&stdio_uart, buffer[i]);
+        }
+#endif
+#endif
+        n = length;
+    } else {
+        FileHandle* fhc = filehandles[fh-3];
+        if (fhc == NULL) return -1;
+
+        n = fhc->write(buffer, length);
+    }
+#ifdef __ARMCC_VERSION
+    return length-n;
+#else
+    return n;
+#endif
+}
+
+#if defined(__ICCARM__)
+extern "C" size_t    __read (int        fh, unsigned char *buffer, size_t       length) {
+#else
+extern "C" int PREFIX(_read)(FILEHANDLE fh, unsigned char *buffer, unsigned int length, int mode) {
+#endif
+    int n; // n is the number of bytes read
+    if (fh < 3) {
+        // only read a character at a time from stdin
+#if DEVICE_SERIAL
+        if (!stdio_uart_inited) init_serial();
+#if MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
+        while (true) {
+            char c = serial_getc(&stdio_uart);
+            if ((c == '\r' && stdio_in_prev != '\n') ||
+                (c == '\n' && stdio_in_prev != '\r')) {
+                stdio_in_prev = c;
+                *buffer = '\n';
+                break;
+            } else if ((c == '\r' && stdio_in_prev == '\n') ||
+                       (c == '\n' && stdio_in_prev == '\r')) {
+                stdio_in_prev = c;
+                // onto next character
+                continue;
+            } else {
+                stdio_in_prev = c;
+                *buffer = c;
+                break;
+            }
+        }
+#else
+        *buffer = serial_getc(&stdio_uart);
+#endif
+#endif
+        n = 1;
+    } else {
+        FileHandle* fhc = filehandles[fh-3];
+        if (fhc == NULL) return -1;
+
+        n = fhc->read(buffer, length);
+    }
+#ifdef __ARMCC_VERSION
+    return length-n;
+#else
+    return n;
+#endif
+}
+
+#ifdef __ARMCC_VERSION
+extern "C" int PREFIX(_istty)(FILEHANDLE fh)
+#else
+extern "C" int _isatty(FILEHANDLE fh)
+#endif
+{
+    /* stdin, stdout and stderr should be tty */
+    if (fh < 3) return 1;
+
+    FileHandle* fhc = filehandles[fh-3];
+    if (fhc == NULL) return -1;
+
+    return fhc->isatty();
+}
+
+extern "C"
+#if defined(__ARMCC_VERSION)
+int _sys_seek(FILEHANDLE fh, long position)
+#elif defined(__ICCARM__)
+long __lseek(int fh, long offset, int whence)
+#else
+int _lseek(FILEHANDLE fh, int offset, int whence)
+#endif
+{
+    if (fh < 3) return 0;
+
+    FileHandle* fhc = filehandles[fh-3];
+    if (fhc == NULL) return -1;
+
+#if defined(__ARMCC_VERSION)
+    return fhc->lseek(position, SEEK_SET);
+#else
+    return fhc->lseek(offset, whence);
+#endif
+}
+
+#ifdef __ARMCC_VERSION
+extern "C" int PREFIX(_ensure)(FILEHANDLE fh) {
+    if (fh < 3) return 0;
+
+    FileHandle* fhc = filehandles[fh-3];
+    if (fhc == NULL) return -1;
+
+    return fhc->fsync();
+}
+
+extern "C" long PREFIX(_flen)(FILEHANDLE fh) {
+    if (fh < 3) return 0;
+
+    FileHandle* fhc = filehandles[fh-3];
+    if (fhc == NULL) return -1;
+
+    return fhc->flen();
+}
+#endif
+
+
+#if !defined(__ARMCC_VERSION) && !defined(__ICCARM__)
+extern "C" int _fstat(int fd, struct stat *st) {
+    if ((STDOUT_FILENO == fd) || (STDERR_FILENO == fd) || (STDIN_FILENO == fd)) {
+        st->st_mode = S_IFCHR;
+        return  0;
+    }
+
+    errno = EBADF;
+    return -1;
+}
+#endif
+
+namespace std {
+extern "C" int remove(const char *path) {
+    FilePath fp(path);
+    FileSystemLike *fs = fp.fileSystem();
+    if (fs == NULL) return -1;
+
+    return fs->remove(fp.fileName());
+}
+
+extern "C" int rename(const char *oldname, const char *newname) {
+    FilePath fpOld(oldname);
+    FilePath fpNew(newname);
+    FileSystemLike *fsOld = fpOld.fileSystem();
+    FileSystemLike *fsNew = fpNew.fileSystem();
+
+    /* rename only if both files are on the same FS */
+    if (fsOld != fsNew || fsOld == NULL) return -1;
+
+    return fsOld->rename(fpOld.fileName(), fpNew.fileName());
+}
+
+extern "C" char *tmpnam(char *s) {
+    return NULL;
+}
+
+extern "C" FILE *tmpfile() {
+    return NULL;
+}
+} // namespace std
+
+#ifdef __ARMCC_VERSION
+extern "C" char *_sys_command_string(char *cmd, int len) {
+    return NULL;
+}
+#endif
+
+extern "C" DIR *opendir(const char *path) {
+    /* root dir is FileSystemLike */
+    if (path[0] == '/' && path[1] == 0) {
+        return FileSystemLike::opendir();
+    }
+
+    FilePath fp(path);
+    FileSystemLike* fs = fp.fileSystem();
+    if (fs == NULL) return NULL;
+
+    return fs->opendir(fp.fileName());
+}
+
+extern "C" struct dirent *readdir(DIR *dir) {
+    return dir->readdir();
+}
+
+extern "C" int closedir(DIR *dir) {
+    return dir->closedir();
+}
+
+extern "C" void rewinddir(DIR *dir) {
+    dir->rewinddir();
+}
+
+extern "C" off_t telldir(DIR *dir) {
+    return dir->telldir();
+}
+
+extern "C" void seekdir(DIR *dir, off_t off) {
+    dir->seekdir(off);
+}
+
+extern "C" int mkdir(const char *path, mode_t mode) {
+    FilePath fp(path);
+    FileSystemLike *fs = fp.fileSystem();
+    if (fs == NULL) return -1;
+
+    return fs->mkdir(fp.fileName(), mode);
+}
+
+#if defined(TOOLCHAIN_GCC)
+/* prevents the exception handling name demangling code getting pulled in */
+#include "mbed_error.h"
+namespace __gnu_cxx {
+    void __verbose_terminate_handler() {
+        error("Exception");
+    }
+}
+extern "C" WEAK void __cxa_pure_virtual(void);
+extern "C" WEAK void __cxa_pure_virtual(void) {
+    exit(1);
+}
+
+#endif
+
+#if defined(TOOLCHAIN_GCC)
+#ifdef   FEATURE_UVISOR
+#include "uvisor-lib/uvisor-lib.h"
+#endif/* FEATURE_UVISOR */
+
+#ifndef  FEATURE_UVISOR
+extern "C" {
+void * __wrap__malloc_r(struct _reent * r, size_t size) {
+    extern void * __real__malloc_r(struct _reent * r, size_t size);
+    return __real__malloc_r(r, size);
+}
+void * __wrap__realloc_r(struct _reent * r, void * ptr, size_t size) {
+    extern void * __real__realloc_r(struct _reent * r, void * ptr, size_t size);
+    return __real__realloc_r(r, ptr, size);
+}
+void __wrap__free_r(struct _reent * r, void * ptr) {
+    extern void __real__free_r(struct _reent * r, void * ptr);
+    __real__free_r(r, ptr);
+}
+}
+#endif/* FEATURE_UVISOR */
+
+extern "C" WEAK void software_init_hook_rtos(void)
+{
+    // Do nothing by default.
+}
+
+extern "C" void software_init_hook(void)
+{
+#ifdef   FEATURE_UVISOR
+    int return_code;
+
+    return_code = uvisor_lib_init();
+    if (return_code) {
+        mbed_die();
+    }
+#endif/* FEATURE_UVISOR */
+
+    software_init_hook_rtos();
+}
+#endif
+
+// ****************************************************************************
+// mbed_main is a function that is called before main()
+// mbed_sdk_init() is also a function that is called before main(), but unlike
+// mbed_main(), it is not meant for user code, but for the SDK itself to perform
+// initializations before main() is called.
+
+extern "C" WEAK void mbed_main(void);
+extern "C" WEAK void mbed_main(void) {
+}
+
+extern "C" WEAK void mbed_sdk_init(void);
+extern "C" WEAK void mbed_sdk_init(void) {
+}
+
+#if defined(TOOLCHAIN_ARM)
+extern "C" int $Super$$main(void);
+
+extern "C" int $Sub$$main(void) {
+    mbed_sdk_init();
+    mbed_main();
+    return $Super$$main();
+}
+#elif defined(TOOLCHAIN_GCC)
+extern "C" int __real_main(void);
+
+extern "C" int __wrap_main(void) {
+    mbed_sdk_init();
+    mbed_main();
+    return __real_main();
+}
+#elif defined(TOOLCHAIN_IAR)
+// IAR doesn't have the $Super/$Sub mechanism of armcc, nor something equivalent
+// to ld's --wrap. It does have a --redirect, but that doesn't help, since redirecting
+// 'main' to another symbol looses the original 'main' symbol. However, its startup
+// code will call a function to setup argc and argv (__iar_argc_argv) if it is defined.
+// Since mbed doesn't use argc/argv, we use this function to call our mbed_main.
+extern "C" void __iar_argc_argv() {
+    mbed_main();
+}
+#endif
+
+// Provide implementation of _sbrk (low-level dynamic memory allocation
+// routine) for GCC_ARM which compares new heap pointer with MSP instead of
+// SP.  This make it compatible with RTX RTOS thread stacks.
+#if defined(TOOLCHAIN_GCC_ARM) || defined(TOOLCHAIN_GCC_CR)
+// Linker defined symbol used by _sbrk to indicate where heap should start.
+extern "C" int __end__;
+
+#if defined(TARGET_CORTEX_A)
+extern "C" uint32_t  __HeapLimit;
+#endif
+
+// Turn off the errno macro and use actual global variable instead.
+#undef errno
+extern "C" int errno;
+
+// For ARM7 only
+register unsigned char * stack_ptr __asm ("sp");
+
+// Dynamic memory allocation related syscall.
+#if defined(TARGET_NUMAKER_PFM_NUC472)
+// Overwrite _sbrk() to support two region model.
+extern "C" void *__wrap__sbrk(int incr);
+extern "C" caddr_t _sbrk(int incr) {
+    return (caddr_t) __wrap__sbrk(incr);
+}
+#else
+extern "C" caddr_t _sbrk(int incr) {
+    static unsigned char* heap = (unsigned char*)&__end__;
+    unsigned char*        prev_heap = heap;
+    unsigned char*        new_heap = heap + incr;
+
+#if defined(TARGET_ARM7)
+    if (new_heap >= stack_ptr) {
+#elif defined(TARGET_CORTEX_A)
+    if (new_heap >= (unsigned char*)&__HeapLimit) {     /* __HeapLimit is end of heap section */
+#else
+    if (new_heap >= (unsigned char*)__get_MSP()) {
+#endif
+        errno = ENOMEM;
+        return (caddr_t)-1;
+    }
+
+    // Additional heap checking if set
+    if (mbed_heap_size && (new_heap >= mbed_heap_start + mbed_heap_size)) {
+        errno = ENOMEM;
+        return (caddr_t)-1;
+    }
+
+    heap = new_heap;
+    return (caddr_t) prev_heap;
+}
+#endif
+#endif
+
+#if defined(TOOLCHAIN_GCC_ARM) || defined(TOOLCHAIN_GCC_CR)
+extern "C" void _exit(int return_code) {
+#else
+namespace std {
+extern "C" void exit(int return_code) {
+#endif
+
+#if DEVICE_STDIO_MESSAGES
+    fflush(stdout);
+    fflush(stderr);
+#endif
+
+#if DEVICE_SEMIHOST
+    if (mbed_interface_connected()) {
+        semihost_exit();
+    }
+#endif
+    if (return_code) {
+        mbed_die();
+    }
+
+    while (1);
+}
+
+#if !defined(TOOLCHAIN_GCC_ARM) && !defined(TOOLCHAIN_GCC_CR)
+} //namespace std
+#endif
+
+
+namespace mbed {
+
+void mbed_set_unbuffered_stream(FILE *_file) {
+#if defined (__ICCARM__)
+    char buf[2];
+    std::setvbuf(_file,buf,_IONBF,NULL);    
+#else
+    setbuf(_file, NULL);
+#endif
+}
+
+int mbed_getc(FILE *_file){
+#if defined (__ICCARM__)
+    /*This is only valid for unbuffered streams*/
+    int res = std::fgetc(_file);
+    if (res>=0){
+        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
+        _file->_Rend = _file->_Wend;
+        _file->_Next = _file->_Wend;
+    }    
+    return res;
+#else    
+    return std::fgetc(_file);
+#endif   
+}
+
+char* mbed_gets(char*s, int size, FILE *_file){
+#if defined (__ICCARM__)
+    /*This is only valid for unbuffered streams*/
+    char *str = fgets(s,size,_file);
+    if (str!=NULL){
+        _file->_Mode = (unsigned short)(_file->_Mode & ~ 0x1000);/* Unset read mode */
+        _file->_Rend = _file->_Wend;
+        _file->_Next = _file->_Wend;
+    }
+    return str;
+#else    
+    return std::fgets(s,size,_file);
+#endif
+}
+
+#if defined (__ICCARM__)
+// Stub out locks when an rtos is not present
+extern "C" WEAK void __iar_system_Mtxinit(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_system_Mtxdst(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_system_Mtxlock(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_system_Mtxunlock(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_file_Mtxinit(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_file_Mtxdst(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_file_Mtxlock(__iar_Rmtx *mutex) {}
+extern "C" WEAK void __iar_file_Mtxunlock(__iar_Rmtx *mutex) {}
+#elif defined(__CC_ARM)
+// Do nothing
+#elif defined (__GNUC__)
+struct _reent;
+// Stub out locks when an rtos is not present
+extern "C" WEAK void __rtos_malloc_lock( struct _reent *_r ) {}
+extern "C" WEAK void __rtos_malloc_unlock( struct _reent *_r ) {}
+extern "C" WEAK void __rtos_env_lock( struct _reent *_r ) {}
+extern "C" WEAK void __rtos_env_unlock( struct _reent *_r ) {}
+
+extern "C" void __malloc_lock( struct _reent *_r )
+{
+    __rtos_malloc_lock(_r);
+}
+
+extern "C" void __malloc_unlock( struct _reent *_r )
+{
+    __rtos_malloc_unlock(_r);
+}
+
+extern "C" void __env_lock( struct _reent *_r )
+{
+    __rtos_env_lock(_r);
+}
+
+extern "C" void __env_unlock( struct _reent *_r )
+{
+    __rtos_env_unlock(_r);
+}
+#endif
+
+} // namespace mbed
+
+void *operator new(std::size_t count)
+{
+    void *buffer = malloc(count);
+    if (NULL == buffer) {
+        error("Operator new out of memory\r\n");
+    }
+    return buffer;
+}
+
+void *operator new[](std::size_t count)
+{
+    void *buffer = malloc(count);
+    if (NULL == buffer) {
+        error("Operator new[] out of memory\r\n");
+    }
+    return buffer;
+}
+
+void operator delete(void *ptr)
+{
+    if (ptr != NULL) {
+        free(ptr);
+    }
+}
+void operator delete[](void *ptr)
+{
+    if (ptr != NULL) {
+        free(ptr);
+    }
+}