1 /* 2 * Operating System Interface 3 * 4 * This provides access to useful OS routines for the sandbox architecture. 5 * They are kept in a separate file so we can include system headers. 6 * 7 * Copyright (c) 2011 The Chromium OS Authors. 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #ifndef __OS_H__ 12 #define __OS_H__ 13 14 #include <linux/types.h> 15 16 struct rtc_time; 17 struct sandbox_state; 18 19 /** 20 * Access to the OS read() system call 21 * 22 * \param fd File descriptor as returned by os_open() 23 * \param buf Buffer to place data 24 * \param count Number of bytes to read 25 * \return number of bytes read, or -1 on error 26 */ 27 ssize_t os_read(int fd, void *buf, size_t count); 28 29 /** 30 * Access to the OS read() system call with non-blocking access 31 * 32 * \param fd File descriptor as returned by os_open() 33 * \param buf Buffer to place data 34 * \param count Number of bytes to read 35 * \return number of bytes read, or -1 on error 36 */ 37 ssize_t os_read_no_block(int fd, void *buf, size_t count); 38 39 /** 40 * Access to the OS write() system call 41 * 42 * \param fd File descriptor as returned by os_open() 43 * \param buf Buffer containing data to write 44 * \param count Number of bytes to write 45 * \return number of bytes written, or -1 on error 46 */ 47 ssize_t os_write(int fd, const void *buf, size_t count); 48 49 /** 50 * Access to the OS lseek() system call 51 * 52 * \param fd File descriptor as returned by os_open() 53 * \param offset File offset (based on whence) 54 * \param whence Position offset is relative to (see below) 55 * \return new file offset 56 */ 57 off_t os_lseek(int fd, off_t offset, int whence); 58 59 /* Defines for "whence" in os_lseek() */ 60 #define OS_SEEK_SET 0 61 #define OS_SEEK_CUR 1 62 #define OS_SEEK_END 2 63 64 /** 65 * Access to the OS open() system call 66 * 67 * \param pathname Pathname of file to open 68 * \param flags Flags, like OS_O_RDONLY, OS_O_RDWR 69 * \return file descriptor, or -1 on error 70 */ 71 int os_open(const char *pathname, int flags); 72 73 #define OS_O_RDONLY 0 74 #define OS_O_WRONLY 1 75 #define OS_O_RDWR 2 76 #define OS_O_MASK 3 /* Mask for read/write flags */ 77 #define OS_O_CREAT 0100 78 79 /** 80 * Access to the OS close() system call 81 * 82 * \param fd File descriptor to close 83 * \return 0 on success, -1 on error 84 */ 85 int os_close(int fd); 86 87 /** 88 * Access to the OS unlink() system call 89 * 90 * \param pathname Path of file to delete 91 * \return 0 for success, other for error 92 */ 93 int os_unlink(const char *pathname); 94 95 /** 96 * Access to the OS exit() system call 97 * 98 * This exits with the supplied return code, which should be 0 to indicate 99 * success. 100 * 101 * @param exit_code exit code for U-Boot 102 */ 103 void os_exit(int exit_code) __attribute__((noreturn)); 104 105 /** 106 * Put tty into raw mode to mimic serial console better 107 * 108 * @param fd File descriptor of stdin (normally 0) 109 * @param allow_sigs Allow Ctrl-C, Ctrl-Z to generate signals rather than 110 * be handled by U-Boot 111 */ 112 void os_tty_raw(int fd, bool allow_sigs); 113 114 /** 115 * Restore the tty to its original mode 116 * 117 * Call this to restore the original terminal mode, after it has been changed 118 * by os_tty_raw(). This is an internal function. 119 */ 120 void os_fd_restore(void); 121 122 /** 123 * Acquires some memory from the underlying os. 124 * 125 * \param length Number of bytes to be allocated 126 * \return Pointer to length bytes or NULL on error 127 */ 128 void *os_malloc(size_t length); 129 130 /** 131 * Free memory previous allocated with os_malloc()/os_realloc() 132 * 133 * This returns the memory to the OS. 134 * 135 * \param ptr Pointer to memory block to free 136 */ 137 void os_free(void *ptr); 138 139 /** 140 * Reallocate previously-allocated memory to increase/decrease space 141 * 142 * This works in a similar way to the C library realloc() function. If 143 * length is 0, then ptr is freed. Otherwise the space used by ptr is 144 * expanded or reduced depending on whether length is larger or smaller 145 * than before. 146 * 147 * If ptr is NULL, then this is similar to calling os_malloc(). 148 * 149 * This function may need to move the memory block to make room for any 150 * extra space, in which case the new pointer is returned. 151 * 152 * \param ptr Pointer to memory block to reallocate 153 * \param length New length for memory block 154 * \return pointer to new memory block, or NULL on failure or if length 155 * is 0. 156 */ 157 void *os_realloc(void *ptr, size_t length); 158 159 /** 160 * Access to the usleep function of the os 161 * 162 * \param usec Time to sleep in micro seconds 163 */ 164 void os_usleep(unsigned long usec); 165 166 /** 167 * Gets a monotonic increasing number of nano seconds from the OS 168 * 169 * \return A monotonic increasing time scaled in nano seconds 170 */ 171 uint64_t os_get_nsec(void); 172 173 /** 174 * Parse arguments and update sandbox state. 175 * 176 * @param state Sandbox state to update 177 * @param argc Argument count 178 * @param argv Argument vector 179 * @return 0 if ok, and program should continue; 180 * 1 if ok, but program should stop; 181 * -1 on error: program should terminate. 182 */ 183 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]); 184 185 /* 186 * Types of directory entry that we support. See also os_dirent_typename in 187 * the C file. 188 */ 189 enum os_dirent_t { 190 OS_FILET_REG, /* Regular file */ 191 OS_FILET_LNK, /* Symbolic link */ 192 OS_FILET_DIR, /* Directory */ 193 OS_FILET_UNKNOWN, /* Something else */ 194 195 OS_FILET_COUNT, 196 }; 197 198 /** A directory entry node, containing information about a single dirent */ 199 struct os_dirent_node { 200 struct os_dirent_node *next; /* Pointer to next node, or NULL */ 201 ulong size; /* Size of file in bytes */ 202 enum os_dirent_t type; /* Type of entry */ 203 char name[0]; /* Name of entry */ 204 }; 205 206 /** 207 * Get a directionry listing 208 * 209 * This allocates and returns a linked list containing the directory listing. 210 * 211 * @param dirname Directory to examine 212 * @param headp Returns pointer to head of linked list, or NULL if none 213 * @return 0 if ok, -ve on error 214 */ 215 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp); 216 217 /** 218 * Get the name of a directory entry type 219 * 220 * @param type Type to cehck 221 * @return string containing the name of that type, or "???" if none/invalid 222 */ 223 const char *os_dirent_get_typename(enum os_dirent_t type); 224 225 /** 226 * Get the size of a file 227 * 228 * @param fname Filename to check 229 * @param size size of file is returned if no error 230 * @return 0 on success or -1 if an error ocurred 231 */ 232 int os_get_filesize(const char *fname, loff_t *size); 233 234 /** 235 * Write a character to the controlling OS terminal 236 * 237 * This bypasses the U-Boot console support and writes directly to the OS 238 * stdout file descriptor. 239 * 240 * @param ch Character to write 241 */ 242 void os_putc(int ch); 243 244 /** 245 * Write a string to the controlling OS terminal 246 * 247 * This bypasses the U-Boot console support and writes directly to the OS 248 * stdout file descriptor. 249 * 250 * @param str String to write (note that \n is not appended) 251 */ 252 void os_puts(const char *str); 253 254 /** 255 * Write the sandbox RAM buffer to a existing file 256 * 257 * @param fname Filename to write memory to (simple binary format) 258 * @return 0 if OK, -ve on error 259 */ 260 int os_write_ram_buf(const char *fname); 261 262 /** 263 * Read the sandbox RAM buffer from an existing file 264 * 265 * @param fname Filename containing memory (simple binary format) 266 * @return 0 if OK, -ve on error 267 */ 268 int os_read_ram_buf(const char *fname); 269 270 /** 271 * Jump to a new executable image 272 * 273 * This uses exec() to run a new executable image, after putting it in a 274 * temporary file. The same arguments and environment are passed to this 275 * new image, with the addition of: 276 * 277 * -j <filename> Specifies the filename the image was written to. The 278 * calling image may want to delete this at some point. 279 * -m <filename> Specifies the file containing the sandbox memory 280 * (ram_buf) from this image, so that the new image can 281 * have access to this. It also means that the original 282 * memory filename passed to U-Boot will be left intact. 283 * 284 * @param dest Buffer containing executable image 285 * @param size Size of buffer 286 */ 287 int os_jump_to_image(const void *dest, int size); 288 289 /** 290 * Read the current system time 291 * 292 * This reads the current Local Time and places it into the provided 293 * structure. 294 * 295 * @param rt Place to put system time 296 */ 297 void os_localtime(struct rtc_time *rt); 298 299 #endif 300