[comp.unix.microport] minor dev nums, bootable disks

brian@n3dmc.UU.NET (Brian Lloyd) (09/12/89)

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.

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.

Thanks in advance.

Brian Lloyd
uunet!n3dmc!brian
brian@n3dmc.uucp
(301) 881-2580

wnp@attctc.Dallas.TX.US (Wolf Paul) (09/12/89)

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

laurie@ucscb.UCSC.EDU (60648000) (09/12/89)

In article <774@n3dmc.UU.NET> brian@n3dmc.UU.NET (Brian Lloyd) writes:
>
>For uPort SysV/AT 2.4 (286).
>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.

You won't be able to do this unless you want to write your own boot code. The
boot code that uport uses has 5.25" geometry hard wired into it. There is also
code in the kernel startup routine that looks at the primary 5.25" high density
floppy only if there is no hard disk to boot from. Both of these would have to
be changed to make a 3.5" boot disk. I did it for the uport 3.0e.1 386 
distribution.

-Ken Chapin
-

plocher%sally@Sun.COM (John Plocher) (09/13/89)

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

I don't have that info anymore, but Wolf Paul (Belated Congradulations, Dad!)
posted a list a while back that might help.

>2.  How do I create a bootable floppy disk for SysV/AT v2.4?

You make a copy of the provided one (dd or diskcopy)

>I have the v2.4 distribution on 1.2Mb 5" floppies but I want to convert to
>1.44 Mb mini floppies.

You can't make a bootable 3" disk.  The boot sequence expects to find specific
things at specific sectors on the disk, and the 5" disks have a different layout
than the 3" ones.

   -John Plocher

PS. Ken Chapin did make a 3" boot disk for 3.0e (386), so he might have more info
    on this - Ken?...

brian@n3dmc.UU.NET (Brian Lloyd) (09/14/89)

In article <9087@saturn.ucsc.edu> laurie@ucscb.UCSC.EDU Ken Chapin writes:
>In article <774@n3dmc.UU.NET> brian@n3dmc.UU.NET (Brian Lloyd) writes:
>>
>>For uPort SysV/AT 2.4 (286).
>>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.
>
>You won't be able to do this unless you want to write your own boot code. The
>boot code that uport uses has 5.25" geometry hard wired into it. There is also
>code in the kernel startup routine that looks at the primary 5.25" high density
>floppy only if there is no hard disk to boot from. Both of these would have to
>be changed to make a 3.5" boot disk. I did it for the uport 3.0e.1 386 
>distribution.
>
>-Ken Chapin
>-

Could you describe the "geometry" that uPort has hard wired?  I was planning
to make the 3.5" drive the primary floppy.

How about another trick: formatting the 3.5" floppy with only 15
sectors/track? Then the 3.5" floppy should be indistinguishable from a
5.25" HD floppy.  I just don't want to put a 5.25" drive in my new
luggable system. 

Perhaps I should look at this another way.  Is there some way to put
both a 5.25" HD drive and a 3.5" HD drive in one of these
lunch-box-with-an-LCD-display cabinets and still have room for at least
1 half-height hard disk.  The key is that the 3.5" floppy is mandatory
but I would take the 5.25" HD drive along for the ride if there is room.

Brian Lloyd
uunet!n3dmc!brian
(301) 881-2580