Baslinux mailing list

[sindi keesan <keesan AT sdf.lonestar.org>]

On Thu, 17 Feb 2005, David Moberg wrote:

> ----- Original Message -----
> From: "sindi keesan" <keesan AT sdf.lonestar.org>
>
> > > > Do I need (in order to have sda4 as a block device):
> > > > CONFIG_BLK_DEV_SD=y
> >
> > Is this the equivalent of insmod scsi_mod and if not, what is?
>
> Nope, if you set this to M you get sd_mod.o. The equivalent of
> scsi_mod.o is CONFIG_SCSI.
>
> BTW, my previous posting neglected to mention that you can build
> the whole SCSI driver system as (a) module(s).


I just read the relevant parts of Configure.help and learned this.

For all scsi devices (including IDE CD-burners used with cdrecord):
scsi_mod.o or CONFIG_SCSI=y

For REAL scsi devices you need the module for the card (aic7xxx.o for
my adaptec 2940) or CONFIG_SCIS_AIC7XXX=y

For  scsi or pseudoscsi CD-ROM devices:  CONFIG_BLK_DEV_SR=y or sr_mod.o
(these show up as sr0 etc).

For CD-writers or SCSI scanners:  CONFIG_CHR_DEV_SG=6 or sg.o  (sg0)
So for a CD burner you need, as Christof suggested, scsi_mod, sr_mod, and 
sg, and also the ide-scsi module and the line in the boot.bat file for it.

I did not get my scsi scanner working with scsi_mod and sg

For block devices which includes parallel port zip drives or scsi hard 
drive (or apparently also scsi zip drives)
sd_mod.o or CONFIG_BLK_DEV_SD
I was missing this module.

I did
insmod scsi_mod
insmod sg
insmod aic7xxx

It found 1 host and I could then mount /dev/sda4 on /zip.

So I don't really need a scsi kernel, like you said, if I can figure
out what is missing to make the scanner work.  scsi_mod, sg, and aic7xxx 
ought to do it, but maybe the order is important?

There is something about Reset SCSI-devices at boot time, for 'scanners of 
older type that do not reset when switched on'.  Default is N because it 
can mess up the hard drives to do a reset.

As often as I expect to use the scanner I could stand to use the aic7xxx.s 
kernel instead, though it is twice as big.  It lets you use a lot of 
other scsi cards as modules, and includes many things I never heard of.

> > what else do I need to configure?
>
> Whatever drivers you need for the devices you want to use. Like Steven
> said, it's a good idea to read the Linux configuration documentation.
>
> > I found in the aic7xxx.s kerneL;
> > CONFIG_CHR_DEV_SR=y                     (instead of sr_mod.o?)
> > CONFIG_CHR_DEV_SG=y                     (instead of sg.o?)
>
> Uh-huh.
>
> > (I used these two for scsi emulation with the cd burner - do I also need
> > them for real scsi?  I have been using bare.i for scsi emulation so
> > that I can listen to the .wav files made with cdda2wav, but I think
> > the BL2 kernel also worked for it with three scsi modules plus
> > ide-scsi.)

> You only need SR if you want to use a CD/DVD drive/burner attached via
> SCSI, ATAPI/IDE-SCSI emulation, or USB. SG is for anything on those busses
> which are not a hard, floppy, flash, or tape drive. You need it for burning
> CDs (but you don't need it to read CDs or DVDs) and for scanners or
> synthesizers (!).

Is the zip drive treated as a hard drive?  Someone told me in DOS it is 
treated as a floppy drive (but assigned a letter following anything IDE).

I have never even seen a synthesizer.

> > CONFIG_SCSI_AIC7XXX=y           I probably need this instead of aic7xxx.o
> > CONFIG_AIC7XXX_CMOS_PER_DEVICE=8        these lines too?
> > CONFIG_AIC7XX_CMOS_RESET_DELAY=5
>
> The first line enables the AIC7XXX. It looks like you want that. The last
> two are configuration options for that driver. The defaults should work
> fine.
>
> > Do I need all of this?  Or anything else not in the BL2 kernel?
>
> See above.
>
> > Why are some scsi devices sga (scanner?), some sda4 (zip), some sr0
> > (cd burner, I think)?   I never used anything scsi until recently,
> > these three devices.
>
> Different devices have different interfaces (best explanation I could
> come up with).

Thanks.  At least I have the zip drive working with BL2 kernel and modules 
now and I will persist with the scanner.  It worked with SW81 adaptec.s 
kernel and with the scsi zip drive plugged into it (and terminated).

Presumably a parport zip drive will be used the same way but with ppa.o 
in addition to sd_mod.

Steven, thanks for steering me to the information.  I did not want to go 
through the configure routine to get at it with ?

If I have lots of RAM, is there any particular advantage to loading the 
five scsi modules rather than compiling into the kernel, for things I 
don't use often such as zip drive, scanner, and cd burner?

If I load the modules I can rmmod them in case I need to use that IRQ (for 
sb and aic7xxx).  Can I do something similar if they are in the kernel?

Any reason NOT to compile with slhc, ppp, parport, parport_pc, lp, the 
sound modules, and the scsi modules (other than sb and aic7xxx)?  They 
don't seem to require interrupts when not in use.  Nor does ethernet 
until I run ifconfig.

For 24MB RAM should I stick to modules for everything?  That computer is 
used mostly for writing scripts this year.

> David
> --

Sindi