1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Operating System Interface 4 * 5 * This provides access to useful OS routines for the sandbox architecture. 6 * They are kept in a separate file so we can include system headers. 7 * 8 * Copyright (c) 2011 The Chromium OS Authors. 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 write() system call 31 * 32 * \param fd File descriptor as returned by os_open() 33 * \param buf Buffer containing data to write 34 * \param count Number of bytes to write 35 * \return number of bytes written, or -1 on error 36 */ 37 ssize_t os_write(int fd, const void *buf, size_t count); 38 39 /** 40 * Access to the OS lseek() system call 41 * 42 * \param fd File descriptor as returned by os_open() 43 * \param offset File offset (based on whence) 44 * \param whence Position offset is relative to (see below) 45 * \return new file offset 46 */ 47 off_t os_lseek(int fd, off_t offset, int whence); 48 49 /* Defines for "whence" in os_lseek() */ 50 #define OS_SEEK_SET 0 51 #define OS_SEEK_CUR 1 52 #define OS_SEEK_END 2 53 54 /** 55 * Access to the OS open() system call 56 * 57 * \param pathname Pathname of file to open 58 * \param flags Flags, like OS_O_RDONLY, OS_O_RDWR 59 * \return file descriptor, or -1 on error 60 */ 61 int os_open(const char *pathname, int flags); 62 63 #define OS_O_RDONLY 0 64 #define OS_O_WRONLY 1 65 #define OS_O_RDWR 2 66 #define OS_O_MASK 3 /* Mask for read/write flags */ 67 #define OS_O_CREAT 0100 68 #define OS_O_TRUNC 01000 69 70 /** 71 * Access to the OS close() system call 72 * 73 * \param fd File descriptor to close 74 * \return 0 on success, -1 on error 75 */ 76 int os_close(int fd); 77 78 /** 79 * Access to the OS unlink() system call 80 * 81 * \param pathname Path of file to delete 82 * \return 0 for success, other for error 83 */ 84 int os_unlink(const char *pathname); 85 86 /** 87 * Access to the OS exit() system call 88 * 89 * This exits with the supplied return code, which should be 0 to indicate 90 * success. 91 * 92 * @param exit_code exit code for U-Boot 93 */ 94 void os_exit(int exit_code) __attribute__((noreturn)); 95 96 /** 97 * Put tty into raw mode to mimic serial console better 98 * 99 * @param fd File descriptor of stdin (normally 0) 100 * @param allow_sigs Allow Ctrl-C, Ctrl-Z to generate signals rather than 101 * be handled by U-Boot 102 */ 103 void os_tty_raw(int fd, bool allow_sigs); 104 105 /** 106 * Restore the tty to its original mode 107 * 108 * Call this to restore the original terminal mode, after it has been changed 109 * by os_tty_raw(). This is an internal function. 110 */ 111 void os_fd_restore(void); 112 113 /** 114 * Acquires some memory from the underlying os. 115 * 116 * \param length Number of bytes to be allocated 117 * \return Pointer to length bytes or NULL on error 118 */ 119 void *os_malloc(size_t length); 120 121 /** 122 * Free memory previous allocated with os_malloc()/os_realloc() 123 * 124 * This returns the memory to the OS. 125 * 126 * \param ptr Pointer to memory block to free 127 */ 128 void os_free(void *ptr); 129 130 /** 131 * Reallocate previously-allocated memory to increase/decrease space 132 * 133 * This works in a similar way to the C library realloc() function. If 134 * length is 0, then ptr is freed. Otherwise the space used by ptr is 135 * expanded or reduced depending on whether length is larger or smaller 136 * than before. 137 * 138 * If ptr is NULL, then this is similar to calling os_malloc(). 139 * 140 * This function may need to move the memory block to make room for any 141 * extra space, in which case the new pointer is returned. 142 * 143 * \param ptr Pointer to memory block to reallocate 144 * \param length New length for memory block 145 * \return pointer to new memory block, or NULL on failure or if length 146 * is 0. 147 */ 148 void *os_realloc(void *ptr, size_t length); 149 150 /** 151 * Access to the usleep function of the os 152 * 153 * \param usec Time to sleep in micro seconds 154 */ 155 void os_usleep(unsigned long usec); 156 157 /** 158 * Gets a monotonic increasing number of nano seconds from the OS 159 * 160 * \return A monotonic increasing time scaled in nano seconds 161 */ 162 uint64_t os_get_nsec(void); 163 164 /** 165 * Parse arguments and update sandbox state. 166 * 167 * @param state Sandbox state to update 168 * @param argc Argument count 169 * @param argv Argument vector 170 * @return 0 if ok, and program should continue; 171 * 1 if ok, but program should stop; 172 * -1 on error: program should terminate. 173 */ 174 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]); 175 176 /* 177 * Types of directory entry that we support. See also os_dirent_typename in 178 * the C file. 179 */ 180 enum os_dirent_t { 181 OS_FILET_REG, /* Regular file */ 182 OS_FILET_LNK, /* Symbolic link */ 183 OS_FILET_DIR, /* Directory */ 184 OS_FILET_UNKNOWN, /* Something else */ 185 186 OS_FILET_COUNT, 187 }; 188 189 /** A directory entry node, containing information about a single dirent */ 190 struct os_dirent_node { 191 struct os_dirent_node *next; /* Pointer to next node, or NULL */ 192 ulong size; /* Size of file in bytes */ 193 enum os_dirent_t type; /* Type of entry */ 194 char name[0]; /* Name of entry */ 195 }; 196 197 /** 198 * Get a directionry listing 199 * 200 * This allocates and returns a linked list containing the directory listing. 201 * 202 * @param dirname Directory to examine 203 * @param headp Returns pointer to head of linked list, or NULL if none 204 * @return 0 if ok, -ve on error 205 */ 206 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp); 207 208 /** 209 * Free directory list 210 * 211 * This frees a linked list containing a directory listing. 212 * 213 * @param node Pointer to head of linked list 214 */ 215 void os_dirent_free(struct os_dirent_node *node); 216 217 /** 218 * Get the name of a directory entry type 219 * 220 * @param type Type to check 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 * os_find_u_boot() - Determine the path to U-Boot proper 291 * 292 * This function is intended to be called from within sandbox SPL. It uses 293 * a few heuristics to find U-Boot proper. Normally it is either in the same 294 * directory, or the directory above (since u-boot-spl is normally in an 295 * spl/ subdirectory when built). 296 * 297 * @fname: Place to put full path to U-Boot 298 * @maxlen: Maximum size of @fname 299 * @return 0 if OK, -NOSPC if the filename is too large, -ENOENT if not found 300 */ 301 int os_find_u_boot(char *fname, int maxlen); 302 303 /** 304 * os_spl_to_uboot() - Run U-Boot proper 305 * 306 * When called from SPL, this runs U-Boot proper. The filename is obtained by 307 * calling os_find_u_boot(). 308 * 309 * @fname: Full pathname to U-Boot executable 310 * @return 0 if OK, -ve on error 311 */ 312 int os_spl_to_uboot(const char *fname); 313 314 /** 315 * Read the current system time 316 * 317 * This reads the current Local Time and places it into the provided 318 * structure. 319 * 320 * @param rt Place to put system time 321 */ 322 void os_localtime(struct rtc_time *rt); 323 324 /** 325 * os_abort() - Raise SIGABRT to exit sandbox (e.g. to debugger) 326 */ 327 void os_abort(void); 328 329 /** 330 * os_mprotect_allow() - Remove write-protection on a region of memory 331 * 332 * The start and length will be page-aligned before use. 333 * 334 * @start: Region start 335 * @len: Region length in bytes 336 * @return 0 if OK, -1 on error from mprotect() 337 */ 338 int os_mprotect_allow(void *start, size_t len); 339 340 /** 341 * os_write_file() - Write a file to the host filesystem 342 * 343 * This can be useful when debugging for writing data out of sandbox for 344 * inspection by external tools. 345 * 346 * @name: File path to write to 347 * @buf: Data to write 348 * @size: Size of data to write 349 * @return 0 if OK, -ve on error 350 */ 351 int os_write_file(const char *name, const void *buf, int size); 352 353 #endif 354