@(#)README 1.1 94/10/31 21:05:02 Copyright (c) 1991 by Sun Microsystems, Inc. 03/31/91 Roger Pham Originated Usage: gtprobe [-v] If -v option is entered, there will be many verbose messages printed besides the basic messages. If a wrong option is entered, the program will abort. This program must run on SunOS Release 4.1 or higher in superuser mode. Previous releases may not have the system command "/usr/etc/devinfo" which is used in this program to probe the SBus slots for devices and what they are mapped into. The following is the general sequence of executions: - Use the system command devinfo to determine the SBus slots that are having hardware device on them. - Check if a 'gt' device is found upon executing. If so, proceed to the next step. If not, it would default to the first unoccupied SBus slot; unless, all three slots are occupied in which case the program will have to abort. - Open the device that user had selected (/dev/sbus1, /dev/sbus2, or /dev/sbus3) and map in the address. - Read the HSA Mode Register. If a timeout occurs which would result a bus error or the system would hang, the HSA is put or specified within the realm of this program the wrong SBus slot. Otherwise, the program proceeds to toggle mode bits inside this register by writting and reading back to verify. - Read the MIA Test Register. If a timeout occurs which would result a bus error or the system would hang, the GT is unconnected, not powered, or a bad cable. Assert a hold to the FE Hold Register. This is to prevent the FE from executing and might overwrite the content of the MIA Test Register. After that, write the test patterns to the Test Register and read each one back for verification. - Read the entire OpenBoot PROM, except for the last 4 bytes because this is the checksum of the PROM. Add all the bytes up to form a calculated checksum. Verify this calculated checksum with the checksum that is deposited in the last location of the Openboot PROM and see if they match. If there is a mismatch, the OpenBoot PROM is bad.