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  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #ifndef __OS_H__
  28 #define __OS_H__
  29
  30 struct sandbox_state;
  31
  32 /**
  33  * Access to the OS read() system call
  34  *
  35  * \param fd    File descriptor as returned by os_open()
  36  * \param buf   Buffer to place data
  37  * \param count Number of bytes to read
  38  * \return number of bytes read, or -1 on error
  39  */
  40 ssize_t os_read(int fd, void *buf, size_t count);
  41
  42 /**
  43  * Access to the OS read() system call with non-blocking access
  44  *
  45  * \param fd    File descriptor as returned by os_open()
  46  * \param buf   Buffer to place data
  47  * \param count Number of bytes to read
  48  * \return number of bytes read, or -1 on error
  49  */
  50 ssize_t os_read_no_block(int fd, void *buf, size_t count);
  51
  52 /**
  53  * Access to the OS write() system call
  54  *
  55  * \param fd    File descriptor as returned by os_open()
  56  * \param buf   Buffer containing data to write
  57  * \param count Number of bytes to write
  58  * \return number of bytes written, or -1 on error
  59  */
  60 ssize_t os_write(int fd, const void *buf, size_t count);
  61
  62 /**
  63  * Access to the OS lseek() system call
  64  *
  65  * \param fd    File descriptor as returned by os_open()
  66  * \param offset        File offset (based on whence)
  67  * \param whence        Position offset is relative to (see below)
  68  * \return new file offset
  69  */
  70 off_t os_lseek(int fd, off_t offset, int whence);
  71
  72 /* Defines for "whence" in os_lseek() */
  73 #define OS_SEEK_SET     0
  74 #define OS_SEEK_CUR     1
  75 #define OS_SEEK_END     2
  76
  77 /**
  78  * Access to the OS open() system call
  79  *
  80  * \param pathname      Pathname of file to open
  81  * \param flags         Flags, like O_RDONLY, O_RDWR
  82  * \return file descriptor, or -1 on error
  83  */
  84 int os_open(const char *pathname, int flags);
  85
  86 #define OS_O_RDONLY     0
  87 #define OS_O_WRONLY     1
  88 #define OS_O_RDWR       2
  89 #define OS_O_MASK       3       /* Mask for read/write flags */
  90 #define OS_O_CREAT      0100
  91
  92 /**
  93  * Access to the OS close() system call
  94  *
  95  * \param fd    File descriptor to close
  96  * \return 0 on success, -1 on error
  97  */
  98 int os_close(int fd);
  99
 100 /**
 101  * Access to the OS exit() system call
 102  *
 103  * This exits with the supplied return code, which should be 0 to indicate
 104  * success.
 105  *
 106  * @param exit_code     exit code for U-Boot
 107  */
 108 void os_exit(int exit_code) __attribute__((noreturn));
 109
 110 /**
 111  * Put tty into raw mode to mimic serial console better
 112  */
 113 void os_tty_raw(int fd);
 114
 115 /**
 116  * Acquires some memory from the underlying os.
 117  *
 118  * \param length        Number of bytes to be allocated
 119  * \return Pointer to length bytes or NULL on error
 120  */
 121 void *os_malloc(size_t length);
 122
 123 /**
 124  * Access to the usleep function of the os
 125  *
 126  * \param usec Time to sleep in micro seconds
 127  */
 128 void os_usleep(unsigned long usec);
 129
 130 /**
 131  * Gets a monotonic increasing number of nano seconds from the OS
 132  *
 133  * \return A monotonic increasing time scaled in nano seconds
 134  */
 135 u64 os_get_nsec(void);
 136
 137 /**
 138  * Parse arguments and update sandbox state.
 139  *
 140  * @param state         Sandbox state to update
 141  * @param argc          Argument count
 142  * @param argv          Argument vector
 143  * @return 0 if ok, and program should continue;
 144  *      1 if ok, but program should stop;
 145  *      -1 on error: program should terminate.
 146  */
 147 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
 148
 149 /*
 150  * Types of directory entry that we support. See also os_dirent_typename in
 151  * the C file.
 152  */
 153 enum os_dirent_t {
 154         OS_FILET_REG,           /* Regular file */
 155         OS_FILET_LNK,           /* Symbolic link */
 156         OS_FILET_DIR,           /* Directory */
 157         OS_FILET_UNKNOWN,       /* Something else */
 158
 159         OS_FILET_COUNT,
 160 };
 161
 162 /** A directory entry node, containing information about a single dirent */
 163 struct os_dirent_node {
 164         struct os_dirent_node *next;    /* Pointer to next node, or NULL */
 165         ulong size;                     /* Size of file in bytes */
 166         enum os_dirent_t type;          /* Type of entry */
 167         char name[0];                   /* Name of entry */
 168 };
 169
 170 /**
 171  * Get a directionry listing
 172  *
 173  * This allocates and returns a linked list containing the directory listing.
 174  *
 175  * @param dirname       Directory to examine
 176  * @param headp         Returns pointer to head of linked list, or NULL if none
 177  * @return 0 if ok, -ve on error
 178  */
 179 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
 180
 181 /**
 182  * Get the name of a directory entry type
 183  *
 184  * @param type          Type to cehck
 185  * @return string containing the name of that type, or "???" if none/invalid
 186  */
 187 const char *os_dirent_get_typename(enum os_dirent_t type);
 188
 189 /**
 190  * Get the size of a file
 191  *
 192  * @param fname         Filename to check
 193  * @return size of file, or -1 if an error ocurred
 194  */
 195 ssize_t os_get_filesize(const char *fname);
 196
 197 #endif