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 O_RDONLY, 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 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 void os_tty_raw(int fd);
 100
 101 /**
 102  * Acquires some memory from the underlying os.
 103  *
 104  * \param length        Number of bytes to be allocated
 105  * \return Pointer to length bytes or NULL on error
 106  */
 107 void *os_malloc(size_t length);
 108
 109 /**
 110  * Free memory previous allocated with os_malloc()/os_realloc()
 111  *
 112  * This returns the memory to the OS.
 113  *
 114  * \param ptr           Pointer to memory block to free
 115  */
 116 void *os_free(void *ptr);
 117
 118 /**
 119  * Reallocate previously-allocated memory to increase/decrease space
 120  *
 121  * This works in a similar way to the C library realloc() function. If
 122  * length is 0, then ptr is freed. Otherwise the space used by ptr is
 123  * expanded or reduced depending on whether length is larger or smaller
 124  * than before.
 125  *
 126  * If ptr is NULL, then this is similar to calling os_malloc().
 127  *
 128  * This function may need to move the memory block to make room for any
 129  * extra space, in which case the new pointer is returned.
 130  *
 131  * \param ptr           Pointer to memory block to reallocate
 132  * \param length        New length for memory block
 133  * \return pointer to new memory block, or NULL on failure or if length
 134  *      is 0.
 135  */
 136 void *os_realloc(void *ptr, size_t length);
 137
 138 /**
 139  * Access to the usleep function of the os
 140  *
 141  * \param usec Time to sleep in micro seconds
 142  */
 143 void os_usleep(unsigned long usec);
 144
 145 /**
 146  * Gets a monotonic increasing number of nano seconds from the OS
 147  *
 148  * \return A monotonic increasing time scaled in nano seconds
 149  */
 150 uint64_t os_get_nsec(void);
 151
 152 /**
 153  * Parse arguments and update sandbox state.
 154  *
 155  * @param state         Sandbox state to update
 156  * @param argc          Argument count
 157  * @param argv          Argument vector
 158  * @return 0 if ok, and program should continue;
 159  *      1 if ok, but program should stop;
 160  *      -1 on error: program should terminate.
 161  */
 162 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
 163
 164 /*
 165  * Types of directory entry that we support. See also os_dirent_typename in
 166  * the C file.
 167  */
 168 enum os_dirent_t {
 169         OS_FILET_REG,           /* Regular file */
 170         OS_FILET_LNK,           /* Symbolic link */
 171         OS_FILET_DIR,           /* Directory */
 172         OS_FILET_UNKNOWN,       /* Something else */
 173
 174         OS_FILET_COUNT,
 175 };
 176
 177 /** A directory entry node, containing information about a single dirent */
 178 struct os_dirent_node {
 179         struct os_dirent_node *next;    /* Pointer to next node, or NULL */
 180         ulong size;                     /* Size of file in bytes */
 181         enum os_dirent_t type;          /* Type of entry */
 182         char name[0];                   /* Name of entry */
 183 };
 184
 185 /**
 186  * Get a directionry listing
 187  *
 188  * This allocates and returns a linked list containing the directory listing.
 189  *
 190  * @param dirname       Directory to examine
 191  * @param headp         Returns pointer to head of linked list, or NULL if none
 192  * @return 0 if ok, -ve on error
 193  */
 194 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
 195
 196 /**
 197  * Get the name of a directory entry type
 198  *
 199  * @param type          Type to cehck
 200  * @return string containing the name of that type, or "???" if none/invalid
 201  */
 202 const char *os_dirent_get_typename(enum os_dirent_t type);
 203
 204 /**
 205  * Get the size of a file
 206  *
 207  * @param fname         Filename to check
 208  * @return size of file, or -1 if an error ocurred
 209  */
 210 ssize_t os_get_filesize(const char *fname);
 211
 212 /**
 213  * Write a character to the controlling OS terminal
 214  *
 215  * This bypasses the U-Boot console support and writes directly to the OS
 216  * stdout file descriptor.
 217  *
 218  * @param ch    Character to write
 219  */
 220 void os_putc(int ch);
 221
 222 /**
 223  * Write a string to the controlling OS terminal
 224  *
 225  * This bypasses the U-Boot console support and writes directly to the OS
 226  * stdout file descriptor.
 227  *
 228  * @param str   String to write (note that \n is not appended)
 229  */
 230 void os_puts(const char *str);
 231
 232 /**
 233  * Write the sandbox RAM buffer to a existing file
 234  *
 235  * @param fname         Filename to write memory to (simple binary format)
 236  * @return 0 if OK, -ve on error
 237  */
 238 int os_write_ram_buf(const char *fname);
 239
 240 /**
 241  * Read the sandbox RAM buffer from an existing file
 242  *
 243  * @param fname         Filename containing memory (simple binary format)
 244  * @return 0 if OK, -ve on error
 245  */
 246 int os_read_ram_buf(const char *fname);
 247
 248 #endif