include/os.h

   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  * Free directory list
 219  *
 220  * This frees a linked list containing a directory listing.
 221  *
 222  * @param node          Pointer to head of linked list
 223  */
 224 void os_dirent_free(struct os_dirent_node *node);
 225
 226 /**
 227  * Get the name of a directory entry type
 228  *
 229  * @param type          Type to check
 230  * @return string containing the name of that type, or "???" if none/invalid
 231  */
 232 const char *os_dirent_get_typename(enum os_dirent_t type);
 233
 234 /**
 235  * Get the size of a file
 236  *
 237  * @param fname         Filename to check
 238  * @param size          size of file is returned if no error
 239  * @return 0 on success or -1 if an error ocurred
 240  */
 241 int os_get_filesize(const char *fname, loff_t *size);
 242
 243 /**
 244  * Write a character to the controlling OS terminal
 245  *
 246  * This bypasses the U-Boot console support and writes directly to the OS
 247  * stdout file descriptor.
 248  *
 249  * @param ch    Character to write
 250  */
 251 void os_putc(int ch);
 252
 253 /**
 254  * Write a string to the controlling OS terminal
 255  *
 256  * This bypasses the U-Boot console support and writes directly to the OS
 257  * stdout file descriptor.
 258  *
 259  * @param str   String to write (note that \n is not appended)
 260  */
 261 void os_puts(const char *str);
 262
 263 /**
 264  * Write the sandbox RAM buffer to a existing file
 265  *
 266  * @param fname         Filename to write memory to (simple binary format)
 267  * @return 0 if OK, -ve on error
 268  */
 269 int os_write_ram_buf(const char *fname);
 270
 271 /**
 272  * Read the sandbox RAM buffer from an existing file
 273  *
 274  * @param fname         Filename containing memory (simple binary format)
 275  * @return 0 if OK, -ve on error
 276  */
 277 int os_read_ram_buf(const char *fname);
 278
 279 /**
 280  * Jump to a new executable image
 281  *
 282  * This uses exec() to run a new executable image, after putting it in a
 283  * temporary file. The same arguments and environment are passed to this
 284  * new image, with the addition of:
 285  *
 286  *      -j <filename>   Specifies the filename the image was written to. The
 287  *                      calling image may want to delete this at some point.
 288  *      -m <filename>   Specifies the file containing the sandbox memory
 289  *                      (ram_buf) from this image, so that the new image can
 290  *                      have access to this. It also means that the original
 291  *                      memory filename passed to U-Boot will be left intact.
 292  *
 293  * @param dest          Buffer containing executable image
 294  * @param size          Size of buffer
 295  */
 296 int os_jump_to_image(const void *dest, int size);
 297
 298 /**
 299  * os_find_u_boot() - Determine the path to U-Boot proper
 300  *
 301  * This function is intended to be called from within sandbox SPL. It uses
 302  * a few heuristics to find U-Boot proper. Normally it is either in the same
 303  * directory, or the directory above (since u-boot-spl is normally in an
 304  * spl/ subdirectory when built).
 305  *
 306  * @fname:      Place to put full path to U-Boot
 307  * @maxlen:     Maximum size of @fname
 308  * @return 0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
 309  */
 310 int os_find_u_boot(char *fname, int maxlen);
 311
 312 /**
 313  * os_spl_to_uboot() - Run U-Boot proper
 314  *
 315  * When called from SPL, this runs U-Boot proper. The filename is obtained by
 316  * calling os_find_u_boot().
 317  *
 318  * @fname:      Full pathname to U-Boot executable
 319  * @return 0 if OK, -ve on error
 320  */
 321 int os_spl_to_uboot(const char *fname);
 322
 323 /**
 324  * Read the current system time
 325  *
 326  * This reads the current Local Time and places it into the provided
 327  * structure.
 328  *
 329  * @param rt            Place to put system time
 330  */
 331 void os_localtime(struct rtc_time *rt);
 332
 333 #endif