include/os.h

   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 /**
 354  * os_read_file() - Read a file from the host filesystem
 355  *
 356  * This can be useful when reading test data into sandbox for use by test
 357  * routines. The data is allocated using os_malloc() and should be freed by
 358  * the caller.
 359  *
 360  * @name:       File path to read from
 361  * @bufp:       Returns buffer containing data read
 362  * @sizep:      Returns size of data
 363  * @return 0 if OK, -ve on error
 364  */
 365 int os_read_file(const char *name, void **bufp, int *sizep);
 366
 367 #endif