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 sandbox_state;
  17
  18 /**
  19  * Access to the OS read() system call
  20  *
  21  * \param fd    File descriptor as returned by os_open()
  22  * \param buf   Buffer to place data
  23  * \param count Number of bytes to read
  24  * \return number of bytes read, or -1 on error
  25  */
  26 ssize_t os_read(int fd, void *buf, size_t count);
  27
  28 /**
  29  * Access to the OS read() system call with non-blocking access
  30  *
  31  * \param fd    File descriptor as returned by os_open()
  32  * \param buf   Buffer to place data
  33  * \param count Number of bytes to read
  34  * \return number of bytes read, or -1 on error
  35  */
  36 ssize_t os_read_no_block(int fd, void *buf, size_t count);
  37
  38 /**
  39  * Access to the OS write() system call
  40  *
  41  * \param fd    File descriptor as returned by os_open()
  42  * \param buf   Buffer containing data to write
  43  * \param count Number of bytes to write
  44  * \return number of bytes written, or -1 on error
  45  */
  46 ssize_t os_write(int fd, const void *buf, size_t count);
  47
  48 /**
  49  * Access to the OS lseek() system call
  50  *
  51  * \param fd    File descriptor as returned by os_open()
  52  * \param offset        File offset (based on whence)
  53  * \param whence        Position offset is relative to (see below)
  54  * \return new file offset
  55  */
  56 off_t os_lseek(int fd, off_t offset, int whence);
  57
  58 /* Defines for "whence" in os_lseek() */
  59 #define OS_SEEK_SET     0
  60 #define OS_SEEK_CUR     1
  61 #define OS_SEEK_END     2
  62
  63 /**
  64  * Access to the OS open() system call
  65  *
  66  * \param pathname      Pathname of file to open
  67  * \param flags         Flags, like OS_O_RDONLY, OS_O_RDWR
  68  * \return file descriptor, or -1 on error
  69  */
  70 int os_open(const char *pathname, int flags);
  71
  72 #define OS_O_RDONLY     0
  73 #define OS_O_WRONLY     1
  74 #define OS_O_RDWR       2
  75 #define OS_O_MASK       3       /* Mask for read/write flags */
  76 #define OS_O_CREAT      0100
  77
  78 /**
  79  * Access to the OS close() system call
  80  *
  81  * \param fd    File descriptor to close
  82  * \return 0 on success, -1 on error
  83  */
  84 int os_close(int fd);
  85
  86 /**
  87  * Access to the OS unlink() system call
  88  *
  89  * \param pathname Path of file to delete
  90  * \return 0 for success, other for error
  91  */
  92 int os_unlink(const char *pathname);
  93
  94 /**
  95  * Access to the OS exit() system call
  96  *
  97  * This exits with the supplied return code, which should be 0 to indicate
  98  * success.
  99  *
 100  * @param exit_code     exit code for U-Boot
 101  */
 102 void os_exit(int exit_code) __attribute__((noreturn));
 103
 104 /**
 105  * Put tty into raw mode to mimic serial console better
 106  *
 107  * @param fd            File descriptor of stdin (normally 0)
 108  * @param allow_sigs    Allow Ctrl-C, Ctrl-Z to generate signals rather than
 109  *                      be handled by U-Boot
 110  */
 111 void os_tty_raw(int fd, bool allow_sigs);
 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  * Get the name of a directory entry type
 210  *
 211  * @param type          Type to cehck
 212  * @return string containing the name of that type, or "???" if none/invalid
 213  */
 214 const char *os_dirent_get_typename(enum os_dirent_t type);
 215
 216 /**
 217  * Get the size of a file
 218  *
 219  * @param fname         Filename to check
 220  * @param size          size of file is returned if no error
 221  * @return 0 on success or -1 if an error ocurred
 222  */
 223 int os_get_filesize(const char *fname, loff_t *size);
 224
 225 /**
 226  * Write a character to the controlling OS terminal
 227  *
 228  * This bypasses the U-Boot console support and writes directly to the OS
 229  * stdout file descriptor.
 230  *
 231  * @param ch    Character to write
 232  */
 233 void os_putc(int ch);
 234
 235 /**
 236  * Write a string to the controlling OS terminal
 237  *
 238  * This bypasses the U-Boot console support and writes directly to the OS
 239  * stdout file descriptor.
 240  *
 241  * @param str   String to write (note that \n is not appended)
 242  */
 243 void os_puts(const char *str);
 244
 245 /**
 246  * Write the sandbox RAM buffer to a existing file
 247  *
 248  * @param fname         Filename to write memory to (simple binary format)
 249  * @return 0 if OK, -ve on error
 250  */
 251 int os_write_ram_buf(const char *fname);
 252
 253 /**
 254  * Read the sandbox RAM buffer from an existing file
 255  *
 256  * @param fname         Filename containing memory (simple binary format)
 257  * @return 0 if OK, -ve on error
 258  */
 259 int os_read_ram_buf(const char *fname);
 260
 261 /**
 262  * Jump to a new executable image
 263  *
 264  * This uses exec() to run a new executable image, after putting it in a
 265  * temporary file. The same arguments and environment are passed to this
 266  * new image, with the addition of:
 267  *
 268  *      -j <filename>   Specifies the filename the image was written to. The
 269  *                      calling image may want to delete this at some point.
 270  *      -m <filename>   Specifies the file containing the sandbox memory
 271  *                      (ram_buf) from this image, so that the new image can
 272  *                      have access to this. It also means that the original
 273  *                      memory filename passed to U-Boot will be left intact.
 274  *
 275  * @param dest          Buffer containing executable image
 276  * @param size          Size of buffer
 277  */
 278 int os_jump_to_image(const void *dest, int size);
 279
 280 #endif