7.7 System Setup and Configuration

The previous discussions focused on the design of the management subsystem for an embedded communications device. This section details configuration and management issues related to system startup.

7.7.1 Boot Parameter Configuration

Chapter 2 discussed using flash images to download an upgrade from a remote host. The system needs the boot monitor to be configured with the IP addresses of the device host to download the image, user name and password for FTP access, interface to use for the boot, and other boot flags as listed below. In a VxWorks™ system, this is a stripped down version of the OS, often termed the bootrom, from the name of the image in the make file.

Typical boot parameters for a VxWorks™ boot are shown below, although this is not a complete list:

• Ethernet IP Address

• Boot File Name

• Remote Host IP Address

• Gateway (Router) IP Address

• FTP User Name

• FTP Password

• Startup Script

• Boot Flags

Additional parameters can be included by creating a new version of the boot ROM and modifying the processing logic. The user needs to configure parameters using a local (serial) terminal and then initiate the boot. The download is performed using a protocol such as FTP or TFTP, implemented in the bootrom. Boot parameter configuration is done using a simple command-line interface, which may have no resemblance to the final CLI used in the device.

It is not possible to use SNMP, HTTP, or any other interface to perform this configuration, as the system does not yet have an IP address to use for these types of communication. When the image is downloaded to flash, the boot parameters can be changed so that subsequent boots are performed from the image in flash, without having to reinitiate a download.

7.7.2 Post-Boot Configuration

Once the image is downloaded, boot parameters can still be changed using SNMP or other mechanisms. After a change, the user saves the changed parameters to EEPROM or flash using SNMP or a CLI. This helps avoid the need for local configuration on the next boot. When the system reboots, it picks up the new boot parameters and downloads the appropriate image.

The management subsystem can also provide a variable which can be set by a manager to initiate a system restart. This can be done for multiple reasons: a misbehaving process, use of a new image or new configuration parameters, restore to default configuration, and so on.