Subject: Re: NetBSD is running now -- questions...
To: None <port-atari@NetBSD.ORG>
From: Volker A. Brandt <firstname.lastname@example.org>
Date: 10/22/1995 12:11:17
In article <m0t6m4T-00007uC@waux11.wau.mis.ah.nl> email@example.com writes:
>> The only thing TOS does, is to read the root sector (sector 0),
>> calculate a checksum, and (if the checksum matches some magic
>> number) execute the root setor code at offset 0. Everything
>> else is left to this root sector code.
This is true on every Atari system. But there is a rule for deciding
from which device the boot sector is chosen. I think it's like this:
1. If it's a reboot, test the device that the last boot was from
2. If 1 fails, try the floppy on A:
3. If 2 fails, try the first SCSI device [TT/Falcon]
4. If 3 fails, try the first ACSI device
>I understood that also the partition id played a role in this.
>I assumed this true because volker said there were bit's in the
>NV ram that determined wich id was chosen
> - first bootable
> - first bootable GEM/XGM
> - first bootable UNX
I guess this is only valid on TTs, I don't know about the Falcon.
>auto-boot. The problem is that people who want to run both NetBSD
>and ASV or Linux (when they create a bootloader), will have a problem.
I think this is a little too much worry!
>Or one could say that they should stick to TOS-boot.
That's what I'd suggest.
>> (The boot code in ROM can only handle harddisks with a 512 bytes
>> sector size, so we don't have to worry about different sector
>> sizes and can happily use the DMAread() XBIOS function.)
We can also use keyboard input and text display output, for example to
prompt for bootflags [-s, kernel name, etc].
>> The secondary loader must then load the kernel from /netbsd.
>> I think it's reasonable to require that the root fylesystem
>> is of type ffs, so that would be the only filesystem type
>> the loader must understand.
>At this point the ufsboot code for one of the other systems might
>be of interest.
>> > The loader should also checkout the hardware config.
The loader should check out as little as possible, to allow for
maximum flexibility. The kernel should do as much as possible.
>> I hope so. Basically we need a very much stripped down ffs
>> driver, allowing us to read a file in the root directory.
>Subdirectories are quite handy too. I don want too much stuff in my
Hmmm ... I believe that we shouldn't make it too complicated there. A
simple working boot loader that pulls in /netbsd would be a great step
forward. Decorations can come later 8-)
Cheers -- Volker
Chirac -- Le fossoyeur de la Grande Nation Volker A. Brandt
Internet: firstname.lastname@example.org Angewandte Mathematik
Phone/FAX number available upon request (Bonn, Germany)