Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!umd5!mimsy!chris From: chris@mimsy.UUCP (Chris Torek) Newsgroups: comp.unix.wizards Subject: Re: How do I boot off of a 2nd controller? Message-ID: <10627@mimsy.UUCP> Date: 11 Mar 88 21:54:04 GMT References: <3661@bloom-beacon.MIT.EDU> Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742 Lines: 59 Summary: may be impossible In article <3661@bloom-beacon.MIT.EDU> nessus@athena.mit.edu (Doug Alan) writes: >... boot a VAXstation-II from a disk drive on a second disk controller. Ultrix may support several uda50 controllers on one bus. 4.2 and 4.3 BSD do not. In 4.xBSD, one does >... I get the Unix boot prompt: > > Boot > : ra(4,0)vmunix or more generally, xx(y,z)pathname where `xx' is one of `hp' `ra' `up' and a few others. `z' is just the partition (on disks at least). `y' is computed as 8 * bus_adapter_index + slave (note 1) Hence ra(4,0) is adapter 0 (uba0) unit 4 (slave 4). Note that there is no room for a controller index! ----- [1] `bus adapter index' is actually `SBI TR - 3' for UBAs on SBI Vaxen, and `UBA nexus - 3' on 750s and 730s. Hence the built-in uda50-unibus in an 8600 is ra(16,z) through ra(23,z), since this UBA is at TR 5. For MBAs, it is `TR - 8' (or nexus minus 8 on 750s). The second SBI on an 8600 is indicated by an MBA index >= 4 (this may not be in 4.3BSD). ----- Under 4.3-tahoe the format will be xx(a,b,c,d)pathname where `a' is the adapter index, b is the controller, c is the drive, and d is the partition. (Multiple SBIs on 8600s will still be kludged with mod-4 or perhaps mod-8 values for `a'.) 8200 BI adapter indicies will not be node numbers (unless we change this), but rather determined by the actual index, such that the first BUA (counting up from node 0) is uba0 and the second is uba1. (Example: two BUAs, one at node 6 and one at node E; the one at node 6 is uba0 and the one at E is uba1.) >Also, how does the boot program know where different >partitions begin? I can configure the kernal so partitions begin >wherever I want them to. How does the boot program know where I've >configured the various partitions to begin? It does not. The partition offsets are compiled into the various standalone drivers. In 4.3-tahoe the partition offset in the label overrides, assuming there is a label. Most of the standalone drivers support labels, although as yet only the hp and uda/ra Unix drivers use them. (The 8200 KDB50 driver does not; it needs to be re-merged with the UDA50 driver. Sigh.) -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris