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 struct sandbox_state;
  15
  16 /**
  17  * Access to the OS read() system call
  18  *
  19  * \param fd    File descriptor as returned by os_open()
  20  * \param buf   Buffer to place data
  21  * \param count Number of bytes to read
  22  * \return number of bytes read, or -1 on error
  23  */
  24 ssize_t os_read(int fd, void *buf, size_t count);
  25
  26 /**
  27  * Access to the OS read() system call with non-blocking access
  28  *
  29  * \param fd    File descriptor as returned by os_open()
  30  * \param buf   Buffer to place data
  31  * \param count Number of bytes to read
  32  * \return number of bytes read, or -1 on error
  33  */
  34 ssize_t os_read_no_block(int fd, void *buf, size_t count);
  35
  36 /**
  37  * Access to the OS write() system call
  38  *
  39  * \param fd    File descriptor as returned by os_open()
  40  * \param buf   Buffer containing data to write
  41  * \param count Number of bytes to write
  42  * \return number of bytes written, or -1 on error
  43  */
  44 ssize_t os_write(int fd, const void *buf, size_t count);
  45
  46 /**
  47  * Access to the OS lseek() system call
  48  *
  49  * \param fd    File descriptor as returned by os_open()
  50  * \param offset        File offset (based on whence)
  51  * \param whence        Position offset is relative to (see below)
  52  * \return new file offset
  53  */
  54 off_t os_lseek(int fd, off_t offset, int whence);
  55
  56 /* Defines for "whence" in os_lseek() */
  57 #define OS_SEEK_SET     0
  58 #define OS_SEEK_CUR     1
  59 #define OS_SEEK_END     2
  60
  61 /**
  62  * Access to the OS open() system call
  63  *
  64  * \param pathname      Pathname of file to open
  65  * \param flags         Flags, like O_RDONLY, O_RDWR
  66  * \return file descriptor, or -1 on error
  67  */
  68 int os_open(const char *pathname, int flags);
  69
  70 #define OS_O_RDONLY     0
  71 #define OS_O_WRONLY     1
  72 #define OS_O_RDWR       2
  73 #define OS_O_MASK       3       /* Mask for read/write flags */
  74 #define OS_O_CREAT      0100
  75
  76 /**
  77  * Access to the OS close() system call
  78  *
  79  * \param fd    File descriptor to close
  80  * \return 0 on success, -1 on error
  81  */
  82 int os_close(int fd);
  83
  84 /**
  85  * Access to the OS exit() system call
  86  *
  87  * This exits with the supplied return code, which should be 0 to indicate
  88  * success.
  89  *
  90  * @param exit_code     exit code for U-Boot
  91  */
  92 void os_exit(int exit_code) __attribute__((noreturn));
  93
  94 /**
  95  * Put tty into raw mode to mimic serial console better
  96  */
  97 void os_tty_raw(int fd);
  98
  99 /**
 100  * Acquires some memory from the underlying os.
 101  *
 102  * \param length        Number of bytes to be allocated
 103  * \return Pointer to length bytes or NULL on error
 104  */
 105 void *os_malloc(size_t length);
 106
 107 /**
 108  * Access to the usleep function of the os
 109  *
 110  * \param usec Time to sleep in micro seconds
 111  */
 112 void os_usleep(unsigned long usec);
 113
 114 /**
 115  * Gets a monotonic increasing number of nano seconds from the OS
 116  *
 117  * \return A monotonic increasing time scaled in nano seconds
 118  */
 119 u64 os_get_nsec(void);
 120
 121 /**
 122  * Parse arguments and update sandbox state.
 123  *
 124  * @param state         Sandbox state to update
 125  * @param argc          Argument count
 126  * @param argv          Argument vector
 127  * @return 0 if ok, and program should continue;
 128  *      1 if ok, but program should stop;
 129  *      -1 on error: program should terminate.
 130  */
 131 int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
 132
 133 /*
 134  * Types of directory entry that we support. See also os_dirent_typename in
 135  * the C file.
 136  */
 137 enum os_dirent_t {
 138         OS_FILET_REG,           /* Regular file */
 139         OS_FILET_LNK,           /* Symbolic link */
 140         OS_FILET_DIR,           /* Directory */
 141         OS_FILET_UNKNOWN,       /* Something else */
 142
 143         OS_FILET_COUNT,
 144 };
 145
 146 /** A directory entry node, containing information about a single dirent */
 147 struct os_dirent_node {
 148         struct os_dirent_node *next;    /* Pointer to next node, or NULL */
 149         ulong size;                     /* Size of file in bytes */
 150         enum os_dirent_t type;          /* Type of entry */
 151         char name[0];                   /* Name of entry */
 152 };
 153
 154 /**
 155  * Get a directionry listing
 156  *
 157  * This allocates and returns a linked list containing the directory listing.
 158  *
 159  * @param dirname       Directory to examine
 160  * @param headp         Returns pointer to head of linked list, or NULL if none
 161  * @return 0 if ok, -ve on error
 162  */
 163 int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
 164
 165 /**
 166  * Get the name of a directory entry type
 167  *
 168  * @param type          Type to cehck
 169  * @return string containing the name of that type, or "???" if none/invalid
 170  */
 171 const char *os_dirent_get_typename(enum os_dirent_t type);
 172
 173 /**
 174  * Get the size of a file
 175  *
 176  * @param fname         Filename to check
 177  * @return size of file, or -1 if an error ocurred
 178  */
 179 ssize_t os_get_filesize(const char *fname);
 180
 181 #endif