+ * @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);
+
+/**
+ * os_setjmp() - Call setjmp()
+ *
+ * Call the host system's setjmp() function.
+ *
+ * @jmp: Buffer to store current execution state
+ * @size: Size of buffer
+ * @return normal setjmp() value if OK, -ENOSPC if @size is too small
+ */
+int os_setjmp(ulong *jmp, int size);
+
+/**
+ * os_longjmp() - Call longjmp()
+ *
+ * Call the host system's longjmp() function.
+ *
+ * @jmp: Buffer where previous execution state was stored
+ * @ret: Value to pass to longjmp()