Path: utzoo!utgpu!watmath!iuvax!mailrus!ames!attctc!wnp From: wnp@attctc.Dallas.TX.US (Wolf Paul) Newsgroups: comp.unix.microport Subject: Re: minor dev nums, bootable disks Keywords: minor device number boot disk Message-ID: <9332@attctc.Dallas.TX.US> Date: 12 Sep 89 02:42:29 GMT References: <774@n3dmc.UU.NET> Reply-To: wnp@attctc.Dallas.TX.US (Wolf Paul) Organization: The Unix(R) Connection BBS, Dallas, Tx Lines: 75 In article <774@n3dmc.UU.NET> brian@n3dmc.UU.NET (Brian Lloyd) writes: > >For uPort SysV/AT 2.4 (286). > >1. What are the minor device numbers for floppy devices? I need numbers >for 1.44Mb mini-floppy and 1.2Mb 5" floppy as the second floppy drives on >a generic AT clone. I also need the minor dev number for 0s25 (that strange >bootable device) for a 1.44Mb mini floppy. Please see the table enclosed at the end for a fairly complete list of Microport 2.4 Floppy minor numbers. >2. How do I create a bootable floppy disk for SysV/AT v2.4? > >I have the v2.4 distribution on 1.2Mb 5" floppies but I want to convert to >1.44 Mb mini floppies. It is my understanding that you need to use "dd" to copy /etc/boot.fd (or similar name, don't have a 286 UNIX handy) to the first block(s) of the floppy, using the "complete disk" device. Then you need to make a file system on the corresponding "all-but-first-track" device (bit 7 set in the minor number), and create a minimal directory hierarchy on it (/etc, /bin, /tmp, maybe more). Then you need to copy reqired files, such as a kernel, /bin/sh, /etc/passwd, and any other commands you need and can fit, to the appropriate directories on that floppy fs. Here is the table for minor number coding: 7 6 5 4 3 2 1 0 | | | | | | | | | | | | | | | +-- if set, drive has 9 sectors/track | | | | | | +---- if set, drive is double-sided | | | | | +------ if set, drive has 80 cylinders | | | | +-------- Drive number ( 0 or 1 ) | | | +---------- if NOT set, drive is high density (1.2 or 1.44) | | +------------ if set, drive is 3.5" | +-------------- if NOT set, read 40-cyl disk on 80-cyl drive (doublestep) +---------------- if set, skip cylinder #0 (INSTALL floppies, 0s25) From this then, result the following minor numbers: For Drive 0: Standard AT 1.2M : 01000110 70 (fd096ds15, 0s24) Bootable AT 1.2M 11000110 198 (0s25) Standard XT 360K : 00010111 23 (fd048ds9) Old XT 320K : 00010110 22 (fd048ds8) Old XT 160 : 00010100 20 (fd048ss8) Quad Density 720K 5.25" : 01010111 87 (fd096ds9) Double Density 720K 3.5" : 01110111 119 (fd0mf2dd) High Density 1.4M 3.5" : 01100110 102 (fd0mf2hd) Bootable HD 1.4M 3.5": 11100110 230 (??? Make up a name!) And for Drive 1: (Add 1000 binary, or 8 decimal to the numbers for Drive 0) Standard AT 1.2M : 01001110 78 (fd096ds15, 0s24) Standard XT 360K : 00011111 31 (fd048ds9) Old XT 320K : 00011110 30 (fd048ds8) Old XT 160 : 00011100 28 (fd048ss8) Quad Density 720K 5.25" : 01011111 95 (fd096ds9) Double Density 720K 3.5" : 01111111 127 (fd0mf2dd) High Density 1.4M 3.5" : 01101110 110 (fd0mf2hd) I have used these minor numbers successfully on my Uport 286 system until I sold it late last year. -- Wolf N. Paul -------------------- ------------------ Until Sept 25, 1989: As of Oct 2, 1989: -------------------- ------------------ 3387 Sam Rayburn Run Kirschenallee 113 Carrollton, TX 75007 A-1220 Vienna, Austria (Europe) wnp@attctc.dallas.tx.us uunet!mcvax!iiasa2!wolfp