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()
 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  * Access to the usleep function of the os
 132  *
 133  * \param usec Time to sleep in micro seconds
 134  */
 135 void os_usleep(unsigned long usec);
 136
 137 /**
 138  * Gets a monotonic increasing number of nano seconds from the OS
 139  *
 140  * \return A monotonic increasing time scaled in nano seconds
 141  */
 142 uint64_t os_get_nsec(void);
 143
 144 /**
 145  * Parse arguments and update sandbox state.
 146  *
 147  * @param state         Sandbox state to update
 148  * @param argc          Argument count
 149  * @param argv          Argument vector
 150  * @return 0 if ok, and program should continue;
 151  *      1 if ok, but program should stop;
 152  *      -1 on error: program should terminate.
 153  */
 154 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
 155
 156 /*
 157  * Types of directory entry that we support. See also os_dirent_typename in
 158  * the C file.
 159  */
 160 enum os_dirent_t {
 161         OS_FILET_REG,           /* Regular file */
 162         OS_FILET_LNK,           /* Symbolic link */
 163         OS_FILET_DIR,           /* Directory */
 164         OS_FILET_UNKNOWN,       /* Something else */
 165
 166         OS_FILET_COUNT,
 167 };
 168
 169 /** A directory entry node, containing information about a single dirent */
 170 struct os_dirent_node {
 171         struct os_dirent_node *next;    /* Pointer to next node, or NULL */
 172         ulong size;                     /* Size of file in bytes */
 173         enum os_dirent_t type;          /* Type of entry */
 174         char name[0];                   /* Name of entry */
 175 };
 176
 177 /**
 178  * Get a directionry listing
 179  *
 180  * This allocates and returns a linked list containing the directory listing.
 181  *
 182  * @param dirname       Directory to examine
 183  * @param headp         Returns pointer to head of linked list, or NULL if none
 184  * @return 0 if ok, -ve on error
 185  */
 186 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
 187
 188 /**
 189  * Free directory list
 190  *
 191  * This frees a linked list containing a directory listing.
 192  *
 193  * @param node          Pointer to head of linked list
 194  */
 195 void os_dirent_free(struct os_dirent_node *node);
 196
 197 /**
 198  * Get the name of a directory entry type
 199  *
 200  * @param type          Type to check
 201  * @return string containing the name of that type, or "???" if none/invalid
 202  */
 203 const char *os_dirent_get_typename(enum os_dirent_t type);
 204
 205 /**
 206  * Get the size of a file
 207  *
 208  * @param fname         Filename to check
 209  * @param size          size of file is returned if no error
 210  * @return 0 on success or -1 if an error ocurred
 211  */
 212 int os_get_filesize(const char *fname, loff_t *size);
 213
 214 /**
 215  * Write a character to the controlling OS terminal
 216  *
 217  * This bypasses the U-Boot console support and writes directly to the OS
 218  * stdout file descriptor.
 219  *
 220  * @param ch    Character to write
 221  */
 222 void os_putc(int ch);
 223
 224 /**
 225  * Write a string to the controlling OS terminal
 226  *
 227  * This bypasses the U-Boot console support and writes directly to the OS
 228  * stdout file descriptor.
 229  *
 230  * @param str   String to write (note that \n is not appended)
 231  */
 232 void os_puts(const char *str);
 233
 234 /**
 235  * Write the sandbox RAM buffer to a existing file
 236  *
 237  * @param fname         Filename to write memory to (simple binary format)
 238  * @return 0 if OK, -ve on error
 239  */
 240 int os_write_ram_buf(const char *fname);
 241
 242 /**
 243  * Read the sandbox RAM buffer from an existing file
 244  *
 245  * @param fname         Filename containing memory (simple binary format)
 246  * @return 0 if OK, -ve on error
 247  */
 248 int os_read_ram_buf(const char *fname);
 249
 250 /**
 251  * Jump to a new executable image
 252  *
 253  * This uses exec() to run a new executable image, after putting it in a
 254  * temporary file. The same arguments and environment are passed to this
 255  * new image, with the addition of:
 256  *
 257  *      -j <filename>   Specifies the filename the image was written to. The
 258  *                      calling image may want to delete this at some point.
 259  *      -m <filename>   Specifies the file containing the sandbox memory
 260  *                      (ram_buf) from this image, so that the new image can
 261  *                      have access to this. It also means that the original
 262  *                      memory filename passed to U-Boot will be left intact.
 263  *
 264  * @param dest          Buffer containing executable image
 265  * @param size          Size of buffer
 266  */
 267 int os_jump_to_image(const void *dest, int size);
 268
 269 /**
 270  * os_find_u_boot() - Determine the path to U-Boot proper
 271  *
 272  * This function is intended to be called from within sandbox SPL. It uses
 273  * a few heuristics to find U-Boot proper. Normally it is either in the same
 274  * directory, or the directory above (since u-boot-spl is normally in an
 275  * spl/ subdirectory when built).
 276  *
 277  * @fname:      Place to put full path to U-Boot
 278  * @maxlen:     Maximum size of @fname
 279  * @return 0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
 280  */
 281 int os_find_u_boot(char *fname, int maxlen);
 282
 283 /**
 284  * os_spl_to_uboot() - Run U-Boot proper
 285  *
 286  * When called from SPL, this runs U-Boot proper. The filename is obtained by
 287  * calling os_find_u_boot().
 288  *
 289  * @fname:      Full pathname to U-Boot executable
 290  * @return 0 if OK, -ve on error
 291  */
 292 int os_spl_to_uboot(const char *fname);
 293
 294 /**
 295  * Read the current system time
 296  *
 297  * This reads the current Local Time and places it into the provided
 298  * structure.
 299  *
 300  * @param rt            Place to put system time
 301  */
 302 void os_localtime(struct rtc_time *rt);
 303
 304 /**
 305  * os_abort() - Raise SIGABRT to exit sandbox (e.g. to debugger)
 306  */
 307 void os_abort(void);
 308
 309 /**
 310  * os_mprotect_allow() - Remove write-protection on a region of memory
 311  *
 312  * The start and length will be page-aligned before use.
 313  *
 314  * @start:      Region start
 315  * @len:        Region length in bytes
 316  * @return 0 if OK, -1 on error from mprotect()
 317  */
 318 int os_mprotect_allow(void *start, size_t len);
 319
 320 /**
 321  * os_write_file() - Write a file to the host filesystem
 322  *
 323  * This can be useful when debugging for writing data out of sandbox for
 324  * inspection by external tools.
 325  *
 326  * @name:       File path to write to
 327  * @buf:        Data to write
 328  * @size:       Size of data to write
 329  * @return 0 if OK, -ve on error
 330  */
 331 int os_write_file(const char *name, const void *buf, int size);
 332
 333 /**
 334  * os_read_file() - Read a file from the host filesystem
 335  *
 336  * This can be useful when reading test data into sandbox for use by test
 337  * routines. The data is allocated using os_malloc() and should be freed by
 338  * the caller.
 339  *
 340  * @name:       File path to read from
 341  * @bufp:       Returns buffer containing data read
 342  * @sizep:      Returns size of data
 343  * @return 0 if OK, -ve on error
 344  */
 345 int os_read_file(const char *name, void **bufp, int *sizep);
 346
 347 /*
 348  * os_find_text_base() - Find the text section in this running process
 349  *
 350  * This tries to find the address of the text section in this running process.
 351  * It can be useful to map the address of functions to the address listed in
 352  * the u-boot.map file.
 353  *
 354  * @return address if found, else NULL
 355  */
 356 void *os_find_text_base(void);
 357
 358 #endif