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Newsgroups: comp.os.386bsd.misc Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!usc!sol.ctr.columbia.edu!hamblin.math.byu.edu!news.byu.edu!cwis.isu.edu!fcom.cc.utah.edu!cs.weber.edu!terry From: terry@cs.weber.edu (A Wizard of Earth C) Subject: Re: Will this work (two IDE drives, DOS and *BSD)? Message-ID: <1993Aug24.200723.26095@fcom.cc.utah.edu> Sender: news@fcom.cc.utah.edu Organization: Weber State University, Ogden, UT References: <CC73xF.8n0@rex.uokhsc.edu> <1993Aug23.164125.1497@fcom.cc.utah.edu> <MYCROFT.93Aug23224109@trinity.gnu.ai.mit.edu> Date: Tue, 24 Aug 93 20:07:23 GMT Lines: 56 In article <MYCROFT.93Aug23224109@trinity.gnu.ai.mit.edu> mycroft@trinity.gnu.ai.mit.edu (Charles Hannum) writes: > >In article <1993Aug23.164125.1497@fcom.cc.utah.edu> terry@cs.weber.edu >(A Wizard of Earth C) writes: > > DOS boot works like: > > DOS MBR(C:) --> DOS BOOT (C:<DOS PARTITION>) --> LOAD FROM DISK(C:<DOS>) > > What you would need is a modified piece of code for all three > places. For NetBSD to boot off the second drive, you'd need a > modified MBR on the first drive, then: > > --> BSD BOOT (C:<BSD PARTITION>) --> LOAD FROM DISK(C:<BSD>) > > Both of these would have to be changed for BSD to boot from a drive > other than the primary drive. > >I don't understand this last bit. NetBSD's boot blocks know quite >well how to load the kernel from a second disk. Type `wd(1,0)/netbsd' >at the prompt. The kernel should do the right thing. If it doesn't, >it's a bug, and we'll be glad to fix it. > >I don't know whether boot managers like OS-BS and BootEasy deal with >booting from a second drive; I've never had occasion to try any of >them. They [OS-BS and BootEasy] don't deal with it. So how are you going to load Julian's boot blocks from another drive so you can tell it to load BSD from another drive? The answer is an assembler an a knowledge of the DOS MBR and more than a bit of patience. As to the load from another, drive, yes, Julian's boot blocks support you typing in the drive and partition (if you already know it and enjoy typing in that syntax) -- but you'd have to be the best typist in the world to get it typed in on my machine in the timeout period before autoboot. My machine gives almost 0 delay (50MHz EISA, 0 wait state, 9ms drive on 1742 SCSI). Even if I were to hack the code to increase the delay, it would be better if the code knew where it was being loaded from so I didn't have to type in something each time (a general pain in anyones book). The secondary boot still needs to know where to get the kernel, but this can be passed with the geometry information from the first stage boot. Of course, I altered my boot blocks (not in any of the areas that would impact your suggested workaround) for > 1M loading and for passing of the BIOS [potentially translated] drive geometry to the disklabel program and for use in a protected mode second stage boot to get around the bad tracking issues when the bad track table is past BIOS [translated] cylinder 1023, so your mileage may vary. Terry Lambert terry@icarus.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.