RedBoot is built as an application on top of eCos. The makefile rules for building RedBoot are part of the eCos CDL package, so it's possible to build eCos from the Configuration Tool, as well as from the command line using ecosconfig.
Building RedBoot requires only a few steps: selecting the platform and the RedBoot template, importing a platform specific configuration file, and finally starting the build.
The platform specific configuration file makes sure the settings are correct for building RedBoot on the given platform. Each platform should provide at least two of these configuration files: redboot_RAM.ecm for a RAM mode RedBoot configuration and redboot_ROM.ecm or redboot_ROMRAM.ecm for a ROM or ROMRAM mode RedBoot configuration. There may be additional configuration files according to the requirements of the particular platform. These files are placed into the install/etc directory of the build tree, or may be found in the misc sub-directory of the platform HAL directory for older releases of eCos.
The RedBoot build process results in a number of files in the install bin directory. The ELF file redboot.elf is the pricipal result. Depending on the platform CDL, there will also be generated versions of RedBoot in other file formats, such as redboot.bin (binary format, good when doing an update of a primary RedBoot image, see the Section called Update the primary RedBoot flash image in Chapter 195), redboot.srec (Motorola S-record format, good when downloading a RAM mode image for execution), and redboot.img (stripped ELF format, good when downloading a RAM mode image for execution, smaller than the .srec file). Some platforms may provide additional file formats and also relocate some of these files to a particular address making them more suitable for downloading using a different boot monitor or flash programming tools.
The platform specific information in the relevant platform's HAL documentation must be consulted as there may be other special instructions required to build RedBoot.