RedBoot is a feature rich boot-ROM monitor, that allows manipulation of the on-board flash, JFFS and YAFFS images, loading and execution of a kernel or executable from either tftp (trivial ftp), http or flash, and gdb debugging stubs. From RedBoot, one can load and execute any standalone binary. Most commonly, a Linux kernel binary is used. One can also write applications within the eCos environment and load them with RedBoot. Please refer to Sourceware for more information on programming for eCos.
By default, a pre-existing RedBoot script is executed on initialization time, if not interrupted by the user within one second. The default script instructs RedBoot to load the Linux kernel from the flash, and instructs the Linux kernel to use the JFFS/YAFFS image on the flash chip for its root file system. One can view the RedBoot defaults for the board, as well as the default script, by entering “fconfig -l” at the RedBoot command prompt (Ctrl+C within one second after power up).
The defaults can be changed by simply entering “fconfig” at the RedBoot prompt and answering the prompts. A final chance to write or discard the changes to the board will be given by RedBoot. Also, the main RedBoot commands can be viewed by entering “help” at the prompt, and further information about a single command can be viewed by typing “help <command name>”.