+void os_exit(int exit_code) __attribute__((noreturn));
+
+/**
+ * Put tty into raw mode to mimic serial console better
+ *
+ * @param fd File descriptor of stdin (normally 0)
+ * @param allow_sigs Allow Ctrl-C, Ctrl-Z to generate signals rather than
+ * be handled by U-Boot
+ */
+void os_tty_raw(int fd, bool allow_sigs);
+
+/**
+ * Restore the tty to its original mode
+ *
+ * Call this to restore the original terminal mode, after it has been changed
+ * by os_tty_raw(). This is an internal function.
+ */
+void os_fd_restore(void);
+
+/**
+ * Acquires some memory from the underlying os.
+ *
+ * \param length Number of bytes to be allocated
+ * \return Pointer to length bytes or NULL on error
+ */
+void *os_malloc(size_t length);
+
+/**
+ * Free memory previous allocated with os_malloc()/os_realloc()
+ *
+ * This returns the memory to the OS.
+ *
+ * \param ptr Pointer to memory block to free
+ */
+void os_free(void *ptr);
+
+/**
+ * Reallocate previously-allocated memory to increase/decrease space
+ *
+ * This works in a similar way to the C library realloc() function. If
+ * length is 0, then ptr is freed. Otherwise the space used by ptr is
+ * expanded or reduced depending on whether length is larger or smaller
+ * than before.
+ *
+ * If ptr is NULL, then this is similar to calling os_malloc().
+ *
+ * This function may need to move the memory block to make room for any
+ * extra space, in which case the new pointer is returned.
+ *
+ * \param ptr Pointer to memory block to reallocate
+ * \param length New length for memory block
+ * \return pointer to new memory block, or NULL on failure or if length
+ * is 0.
+ */
+void *os_realloc(void *ptr, size_t length);
+
+/**
+ * Access to the usleep function of the os
+ *
+ * \param usec Time to sleep in micro seconds
+ */
+void os_usleep(unsigned long usec);
+
+/**
+ * Gets a monotonic increasing number of nano seconds from the OS
+ *
+ * \return A monotonic increasing time scaled in nano seconds
+ */
+uint64_t os_get_nsec(void);
+
+/**
+ * Parse arguments and update sandbox state.
+ *
+ * @param state Sandbox state to update
+ * @param argc Argument count
+ * @param argv Argument vector
+ * @return 0 if ok, and program should continue;
+ * 1 if ok, but program should stop;
+ * -1 on error: program should terminate.
+ */
+int os_parse_args(struct sandbox_state *state, int argc, char *argv[]);
+
+/*
+ * Types of directory entry that we support. See also os_dirent_typename in
+ * the C file.
+ */
+enum os_dirent_t {
+ OS_FILET_REG, /* Regular file */
+ OS_FILET_LNK, /* Symbolic link */
+ OS_FILET_DIR, /* Directory */
+ OS_FILET_UNKNOWN, /* Something else */
+
+ OS_FILET_COUNT,
+};
+
+/** A directory entry node, containing information about a single dirent */
+struct os_dirent_node {
+ struct os_dirent_node *next; /* Pointer to next node, or NULL */
+ ulong size; /* Size of file in bytes */
+ enum os_dirent_t type; /* Type of entry */
+ char name[0]; /* Name of entry */
+};
+
+/**
+ * Get a directionry listing
+ *
+ * This allocates and returns a linked list containing the directory listing.
+ *
+ * @param dirname Directory to examine
+ * @param headp Returns pointer to head of linked list, or NULL if none
+ * @return 0 if ok, -ve on error
+ */
+int os_dirent_ls(const char *dirname, struct os_dirent_node **headp);
+
+/**
+ * Free directory list
+ *
+ * This frees a linked list containing a directory listing.
+ *
+ * @param node Pointer to head of linked list
+ */
+void os_dirent_free(struct os_dirent_node *node);
+
+/**
+ * Get the name of a directory entry type
+ *
+ * @param type Type to check
+ * @return string containing the name of that type, or "???" if none/invalid
+ */
+const char *os_dirent_get_typename(enum os_dirent_t type);
+
+/**
+ * Get the size of a file
+ *
+ * @param fname Filename to check
+ * @param size size of file is returned if no error
+ * @return 0 on success or -1 if an error ocurred
+ */
+int os_get_filesize(const char *fname, loff_t *size);
+
+/**
+ * Write a character to the controlling OS terminal
+ *
+ * This bypasses the U-Boot console support and writes directly to the OS
+ * stdout file descriptor.
+ *
+ * @param ch Character to write
+ */
+void os_putc(int ch);
+
+/**
+ * Write a string to the controlling OS terminal
+ *
+ * This bypasses the U-Boot console support and writes directly to the OS
+ * stdout file descriptor.
+ *
+ * @param str String to write (note that \n is not appended)
+ */
+void os_puts(const char *str);
+
+/**
+ * Write the sandbox RAM buffer to a existing file
+ *
+ * @param fname Filename to write memory to (simple binary format)
+ * @return 0 if OK, -ve on error
+ */
+int os_write_ram_buf(const char *fname);
+
+/**
+ * Read the sandbox RAM buffer from an existing file
+ *
+ * @param fname Filename containing memory (simple binary format)
+ * @return 0 if OK, -ve on error
+ */
+int os_read_ram_buf(const char *fname);
+
+/**
+ * Jump to a new executable image
+ *
+ * This uses exec() to run a new executable image, after putting it in a
+ * temporary file. The same arguments and environment are passed to this
+ * new image, with the addition of:
+ *
+ * -j <filename> Specifies the filename the image was written to. The
+ * calling image may want to delete this at some point.
+ * -m <filename> Specifies the file containing the sandbox memory
+ * (ram_buf) from this image, so that the new image can
+ * have access to this. It also means that the original
+ * memory filename passed to U-Boot will be left intact.
+ *
+ * @param dest Buffer containing executable image
+ * @param size Size of buffer
+ */
+int os_jump_to_image(const void *dest, int size);
+
+/**
+ * os_find_u_boot() - Determine the path to U-Boot proper
+ *
+ * This function is intended to be called from within sandbox SPL. It uses
+ * a few heuristics to find U-Boot proper. Normally it is either in the same
+ * directory, or the directory above (since u-boot-spl is normally in an
+ * spl/ subdirectory when built).
+ *
+ * @fname: Place to put full path to U-Boot
+ * @maxlen: Maximum size of @fname
+ * @return 0 if OK, -NOSPC if the filename is too large, -ENOENT if not found
+ */
+int os_find_u_boot(char *fname, int maxlen);
+
+/**
+ * os_spl_to_uboot() - Run U-Boot proper
+ *
+ * When called from SPL, this runs U-Boot proper. The filename is obtained by
+ * calling os_find_u_boot().
+ *
+ * @fname: Full pathname to U-Boot executable
+ * @return 0 if OK, -ve on error
+ */
+int os_spl_to_uboot(const char *fname);
+
+/**
+ * Read the current system time
+ *
+ * This reads the current Local Time and places it into the provided
+ * structure.
+ *
+ * @param rt Place to put system time
+ */
+void os_localtime(struct rtc_time *rt);
+
+#endif