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ZEUS Embedded Linux Development Kit Quickstart RedBoot

RedBoot

What is RedBoot?

RedBoot is a complete bootstrap environment for embedded systems. Based on the

eCos Hardware Abstraction Layer, RedBoot inherits the eCos qualities of reliability,

compactness, configurability, and portability.

RedBoot enables download and execution of embedded applications via serial or

Ethernet, including embedded Linux and eCos applications. It can be used for both

product development (debug support) and in deployed products in the field (Flash

update and network booting).

Ethernet download support is included. This means RedBoot can retrieve its IP

parameters via BOOTP or DHCP, and program images can be downloaded using

TFTP or HTTP. Images can also be downloaded over serial (using X- or Y-modem) or

loaded from a JFFS2 file system on the on-board Flash.

An interactive command-line interface is accessible via serial or Ethernet and allows

management of Flash images, image download, RedBoot configuration, etc. For

unattended or automated startup, boot scripts can be stored in Flash. This allows, for

example, loading of images from Flash or a TFTP server.

You cannot use the command-line interface via Ethernet if you have an

automatic boot script enabled which launches an application or another

operating system, since RedBoot does not stop to listen for TCP/IP activity.

The AEL Embedded Linux Technical Manual contains details of many of the RedBoot

commands that are useful when using RedBoot as a boot loader for another operating

system (such as Linux) or to launch an application. Full RedBoot documentation is

available in the eCos Reference Manual, which is in the /manuals/ folder on the

Development Kit CD.

Default boot script

The default boot script on the ZEUS loads a Linux kernel from the JFFS2 file system

and executes it:

clock –L 16 –N 5

mount -t jffs2 -f filesystem

load -r -b %{FREEMEMLO} %{kernel}

exec -c %{cmdline}

%{FREEMEMLO}

is a predefined alias for the lowest address of available memory.

%{kernel} is an alias for the full path name of the Linux kernel to boot.

%{cmdline} is an alias for the kernel command line to use.

Refer to the AEL Embedded Linux Technical Manual for further details.