AT&T 3B2/300 Technical Reference Manual page 390

- - - - - - - - - - - - - - - - - - - - - - - - - - - FUNCTIONAL DESCRIPTION
System Board Firmware
The system board firmware is programmed instructions stored in ROM which form the basic
operating system when the system is not running the UNIX operating system. The purpose of this
firmware is to initialize the system and provide the means to load and run other programs such as the
UNIX operating system, filledt, and dgmon. The firmware level built-in programs are listed below:
baud Change the firmware baud rate. Valid firmware baud rates are 50, 75, 110, 134,
150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, and 38400. The default baud
rate is 9600.
edt
errorinfo
Display the Equipped Device Table (EDT) data.
Display expanded firmware error message information. This capability is provided
with firmware PF3 and later versions.
express
newkey
passwd
sysdump
version
Enable/disable diagnostics execution during reboot.
Make a new floppy key.
Change the firmware password.
Copy the system image (RAM) to floppy disks.
Display firmware version information.
When the system is RESET or first powered on, the system board firmware controls the
initialization of the system. The sequence of events is as follows:
• Test processor sanity.
• Check ROM.
• Check NVRAM.
• Check RAM.
• Check DUART.
• Check Disk Sanity.
• Self-configuration (build the EDT).
• Run normal diagnostics on all equipped boards/cards listed in the EDT. (If not disabled via the
express command.)
• Boot the UNIX operating system.
FUNCTIONAL DESCRIPTION 3-137