phb@dcdwest.UUCP (Peter H. Berens) (02/24/88)
We have a device driver for a memory mapped device that crashes the system when the board is not installed in the system and someone opens the device node. We would like to be able to use peek or poke in the open routine to determine if the memory addresses the board responds to are present, however xenix does not appear to support any such functions as peek or poke to carry this out. Does anyone know how this should be handled under xenix? All the example device drivers do not appear to deal with this problem. Thanks in advance.
terry@wsccs.UUCP (terry) (03/04/88)
In article <284@dcdwest.UUCP>, phb@dcdwest.UUCP (Peter H. Berens) writes: > We have a device driver for a memory mapped device that crashes the > system when the board is not installed in the system and someone opens > the device node. We would like to be able to use peek or poke in the > open routine to determine if the memory addresses the board responds > to are present Use a setuid(geteuid()) root program (chmod 4755) to open /dev/mem and lseek() to your offset location. Then just read. :-) PS: This is a nifty way to put one of thos damn clocks in the upper-right hand corner of your screen... just write to the upper right-hand corner. | Terry Lambert UUCP: ...!decvax!utah-cs!century!terry | | @ Century Software or : ...utah-cs!uplherc!sp7040!obie!wsccs!terry | | SLC, Utah | | These opinions are not my companies, but if you find them | | useful, send a $20.00 donation to Brisbane Australia... | | 'There are monkey boys in the facility. Do not be alarmed; you are secure' |