Marco Zecchini
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Example_RTOS
Rtos API example
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LocalFileSystem.cpp
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2006-2013 ARM Limited 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http://www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 #include "platform/LocalFileSystem.h" 00017 00018 #if DEVICE_LOCALFILESYSTEM 00019 00020 #include "platform/mbed_semihost_api.h" 00021 #include <string.h> 00022 #include <stdio.h> 00023 #include <errno.h> 00024 00025 namespace mbed { 00026 00027 /* Extension to FINFO type defined in RTL.h (in Keil RL) - adds 'create time'. */ 00028 typedef struct { 00029 unsigned char hr; /* Hours [0..23] */ 00030 unsigned char min; /* Minutes [0..59] */ 00031 unsigned char sec; /* Seconds [0..59] */ 00032 unsigned char day; /* Day [1..31] */ 00033 unsigned char mon; /* Month [1..12] */ 00034 unsigned short year; /* Year [1980..2107] */ 00035 } FTIME; 00036 00037 typedef struct { /* File Search info record */ 00038 char name[32]; /* File name */ 00039 long size; /* File size in bytes */ 00040 int fileID; /* System File Identification */ 00041 FTIME create_time; /* Date & time file was created */ 00042 FTIME write_time; /* Date & time of last write */ 00043 } XFINFO; 00044 00045 #define RESERVED_FOR_USER_APPLICATIONS (0x100) /* 0x100 - 0x1ff */ 00046 #define USR_XFFIND (RESERVED_FOR_USER_APPLICATIONS + 0) 00047 00048 static int xffind (const char *pattern, XFINFO *info) { 00049 unsigned param[4]; 00050 00051 param[0] = (unsigned long)pattern; 00052 param[1] = (unsigned long)strlen(pattern); 00053 param[2] = (unsigned long)info; 00054 param[3] = (unsigned long)sizeof(XFINFO); 00055 00056 return __semihost(USR_XFFIND, param); 00057 } 00058 00059 #define OPEN_R 0 00060 #define OPEN_B 1 00061 #define OPEN_PLUS 2 00062 #define OPEN_W 4 00063 #define OPEN_A 8 00064 #define OPEN_INVALID -1 00065 00066 int posix_to_semihost_open_flags(int flags) { 00067 /* POSIX flags -> semihosting open mode */ 00068 int openmode; 00069 if (flags & O_RDWR) { 00070 /* a plus mode */ 00071 openmode = OPEN_PLUS; 00072 if (flags & O_APPEND) { 00073 openmode |= OPEN_A; 00074 } else if (flags & O_TRUNC) { 00075 openmode |= OPEN_W; 00076 } else { 00077 openmode |= OPEN_R; 00078 } 00079 } else if (flags & O_WRONLY) { 00080 /* write or append */ 00081 if (flags & O_APPEND) { 00082 openmode = OPEN_A; 00083 } else { 00084 openmode = OPEN_W; 00085 } 00086 } else if (flags == O_RDONLY) { 00087 /* read mode */ 00088 openmode = OPEN_R; 00089 } else { 00090 /* invalid flags */ 00091 openmode = OPEN_INVALID; 00092 } 00093 00094 return openmode; 00095 } 00096 00097 FILEHANDLE local_file_open(const char* name, int flags) { 00098 int openmode = posix_to_semihost_open_flags(flags); 00099 if (openmode == OPEN_INVALID) { 00100 return (FILEHANDLE)NULL; 00101 } 00102 00103 FILEHANDLE fh = semihost_open(name, openmode); 00104 if (fh == -1) { 00105 return (FILEHANDLE)NULL; 00106 } 00107 00108 return fh; 00109 } 00110 00111 LocalFileHandle::LocalFileHandle(FILEHANDLE fh) : _fh(fh), pos(0) { 00112 // No lock needed in constructor 00113 } 00114 00115 int LocalFileHandle::close() { 00116 int retval = semihost_close(_fh); 00117 delete this; 00118 return retval; 00119 } 00120 00121 ssize_t LocalFileHandle::write(const void *buffer, size_t length) { 00122 lock(); 00123 ssize_t n = semihost_write(_fh, (const unsigned char*)buffer, length, 0); // number of characters not written 00124 n = length - n; // number of characters written 00125 pos += n; 00126 unlock(); 00127 return n; 00128 } 00129 00130 ssize_t LocalFileHandle::read(void *buffer, size_t length) { 00131 lock(); 00132 ssize_t n = semihost_read(_fh, (unsigned char*)buffer, length, 0); // number of characters not read 00133 n = length - n; // number of characters read 00134 pos += n; 00135 unlock(); 00136 return n; 00137 } 00138 00139 int LocalFileHandle::isatty() { 00140 lock(); 00141 int ret = semihost_istty(_fh); 00142 unlock(); 00143 return ret; 00144 } 00145 00146 off_t LocalFileHandle::seek(off_t position, int whence) { 00147 lock(); 00148 if (whence == SEEK_CUR) { 00149 position += pos; 00150 } else if (whence == SEEK_END) { 00151 position += semihost_flen(_fh); 00152 } /* otherwise SEEK_SET, so position is fine */ 00153 00154 /* Always seems to return -1, so just ignore for now. */ 00155 semihost_seek(_fh, position); 00156 pos = position; 00157 unlock(); 00158 return position; 00159 } 00160 00161 int LocalFileHandle::sync() { 00162 lock(); 00163 int ret = semihost_ensure(_fh); 00164 unlock(); 00165 return ret; 00166 } 00167 00168 off_t LocalFileHandle::size() { 00169 lock(); 00170 off_t off = semihost_flen(_fh); 00171 unlock(); 00172 return off; 00173 } 00174 00175 void LocalFileHandle::lock() { 00176 _mutex.lock(); 00177 } 00178 00179 void LocalFileHandle::unlock() { 00180 _mutex.unlock(); 00181 } 00182 00183 class LocalDirHandle : public DirHandle { 00184 00185 public: 00186 XFINFO info; 00187 00188 LocalDirHandle() : info() { 00189 } 00190 00191 virtual int close() { 00192 // No lock can be used in destructor 00193 delete this; 00194 return 0; 00195 } 00196 00197 virtual int read(struct dirent *ent) { 00198 lock(); 00199 if (xffind("*", &info)!=0) { 00200 unlock(); 00201 return 0; 00202 } 00203 memcpy(ent->d_name, info.name, sizeof(info.name)); 00204 unlock(); 00205 return 1; 00206 } 00207 00208 virtual void rewind() { 00209 lock(); 00210 info.fileID = 0; 00211 unlock(); 00212 } 00213 00214 virtual off_t tell() { 00215 lock(); 00216 int fileId = info.fileID; 00217 unlock(); 00218 return fileId; 00219 } 00220 00221 virtual void seek(off_t offset) { 00222 lock(); 00223 info.fileID = offset; 00224 unlock(); 00225 } 00226 00227 protected: 00228 PlatformMutex _mutex; 00229 00230 virtual void lock() { 00231 _mutex.lock(); 00232 } 00233 00234 virtual void unlock() { 00235 _mutex.unlock(); 00236 } 00237 }; 00238 00239 int LocalFileSystem::open(FileHandle **file, const char* name, int flags) { 00240 // No global state modified so function is thread safe 00241 00242 /* reject filenames with / in them */ 00243 for (const char *tmp = name; *tmp; tmp++) { 00244 if (*tmp == '/') { 00245 return -EINVAL; 00246 } 00247 } 00248 00249 int openmode = posix_to_semihost_open_flags(flags); 00250 if (openmode == OPEN_INVALID) { 00251 return -EINVAL; 00252 } 00253 00254 FILEHANDLE fh = semihost_open(name, openmode); 00255 if (fh == -1) { 00256 return -EIO; 00257 } 00258 00259 *file = new LocalFileHandle(fh); 00260 return 0; 00261 } 00262 00263 int LocalFileSystem::remove(const char *filename) { 00264 // No global state modified so function is thread safe 00265 00266 return semihost_remove(filename); 00267 } 00268 00269 int LocalFileSystem::open(DirHandle **dir, const char *name) { 00270 // No global state modified so function is thread safe 00271 00272 *dir = new LocalDirHandle(); 00273 return 0; 00274 } 00275 00276 } // namespace mbed 00277 00278 #endif
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