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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!msunews!agate!howland.reston.ans.net!Germany.EU.net!ruhr.de!robkaos!robsch From: robsch@robkaos.ruhr.de (Robert Schien) Subject: Re: FreeBSD install - suggestions needed X-Newsreader: TIN [version 1.2 PL2] Organization: Private System, Essen, Germany Message-ID: <1995Jan22.132924.2650@robkaos.ruhr.de> References: <3fsjk6$otr@wolfe.wimsey.com> Date: Sun, 22 Jan 1995 13:29:24 GMT Lines: 82 John Henders (jhenders@vanbc.wimsey.com) wrote: : I have a rather crowded setup on my computer, and I want to : complicate it more by installing FreeeBSD. I have 2 IDE drives, one with : DOS and one with OS/2. I also have a 1542b with 2 scsi drives, one of : which has linux on it. I want to put FreeBSD on the other. : Because the 1542b bios doesn't work with 2 IDE drives in place, : I have a 15 meg partition on one of the IDE drives that I use to put : linux kernels on, and the DOS, OS/2 and 15meg linux partition are all : active and selectable from the OS/2 boot manager. I am planning, if it's : possible, to split the 15 meg partition and use a similar method to boot : FreeBSD if posssible. : However, after reading the INSTALL txt and the FAQ, a few things : aren't clear and I was hoping someone could suggest the most elegant way : to get FreeBSD onto this setup. Feel free to point me to any other : install documentation I may have missed. : I tried to install from the boot floppys from ftp.cdrom.com. I : partitioned the disk, but when it came time to roboot, there was, of : course, no way to to boot from the scsi drive. Is there a way to tell : the boot kernel on the floppy to mount the scsi file system? Also, I : didn't see it written down anywhere, but can I put the bindist/* files : on a dos partition and install them from there? : The alternatives I see are a) Disconnect my OS/2 ide drive and : re jumper the dos drive, so the boot loader can boot the kernel from the : scsi drive, or b) Attempt to do a minimal install on the 15 meg ide : partition and mount the scsi as /usr until I can get enough FreeBSD : installed to change things around to boot the way I want. If no one can : suggest a more elegant way, option b would be my preference, if : possible. : Suggestions? Yeah, creative people have a crowded setup :-) The problem you are suffering from is the fact that you can boot only from the first two 'BIOS drives'. Let me explain this a litte further: When you boot a PC, the BIOS issues an interrupt and reads the first sector of the first drive into memeory and the bootstrap process begins. When you have only IDE drives in your system, you have entries selected for them in the standard PC BIOS. When you have only SCSI drives in your system, the BIOS support comes from the host SCSI host adapter. Nevertheless, the boot process is the same. What differs is that in the case of SCSI the host adapter BIOS translates the boot interrupt into SCSI commands which are sent to the SCSI drive to read the first sector. This means when you have both IDE and SCSI drives in your system and you disable the IDE drives in the PC-BIOS, you boot from the (first) SCSI drive. However, you get problems when you have more than two drives (irrespective of SCSI and/or IDE) and want to boot from the third drive, for example . Because of the archaic PC architecture BIOS knows only about two drives (usually known as C: and D:). Of course, as soon as you have an real OS (like Linux or FreeBSD) running, you can access all the drives, because these OSs have their own drivers and don't rely on BIOS. Therefore, you can install FreeBSD on any SCSI drive (provided there are enough minor devices enabled in the kernel), but you're stuck when you want to BOOT from, let's say, the fifth drive :-) To summarize, when it comes to booting you rely on the PC BIOS (various boot managers do, too). What you need, would be a boot manager which can access all drives. But this would mean that the boot manager would know about SCSI :-( What can you do? One solution is: disable your IDE drives in the standard CMOS setup. You will now have only 2 drives for the BIOS and you can boot from the first or (via a boot manager) from the second SCSI drive. But always enabling and disabling in the BIOS is annoying :-( Another solution would be: boot from the first IDE drive as usual and execute a program which accesses the boot blocks of the SCSI drives via ASPI or so. Unfortunately, such a program doesn't seem to exist. A further solution: To run various OSs, simply create small root partitions of all the OSs on the first IDE drive. Robert