Re: bootloader & head.S weirdness (patch)

Re: bootloader & head.S weirdness (patch)

[Benjamin Herrenschmidt]

Ok, I posted the very first version of this bootloader. I'd appreciate
any comment, suggestion, etc... It's called "yaboot" and is on my test page

<http://calvaweb.calvacom.fr/bh40/test.html>

It's targeted for newworld machines only (machines with a working OF that
can load ELF binaries). It has a quik-like interface.

The config file must be named "yaboot.conf and located next to yaboot
itself, currently I put both on the first HFS volume of my disk, this
way, I can launch it with the simple OF command "boot hd:yaboot".

(Note that it's better to type boot hd:p,yaboot where "p" is the
partition number. If you don't do so, the bootloader will have to look at
all partitions it can read on device "hd" 
until it finds yaboot.conf since I didn't manage to find out the
partition number I was loaded from).

It supports loading files (both kernel and initrd) from any supported OF
disklabel/filesystem, and is had built-in ext2 support (only on Apple
partition maps for now). I'll add a built-in ISO (OF one doesn't seem to
work correctly) soon and also support for ext2 on PC disklabel partition
maps when I find some time>
Note also that currently, loading files from ext2 can be very slow, this
will be fixed in a future version. (The first time I tested, I thought it
was crashed, there is no spinning thing nor progress bar yet).

The kernel is loaded at 0x1000000 (16Mb). Currently, I've not been able
to boot successfully unless I apply the patch I posted earlier (that
disables the MMU after prom_init). I'll probably add an option for
specifying the load base on a per-kernel image basis. The bootloader
itself uses the range 0x200000->0x400000 (2Mb->4Mb) for now.

The syntax for a kernel image path (or initrd path) is a normal OF
syntax, for example:

hd:8,/boot/vmlinux

means the file "/boot/vmlinux" on partition 8 of device "hd". (hd is an
alias to the internal IDE disk of most macs). The parsing is a little bit
different than what quik used to do, so be careful.

I'll add a README and a sample config file with the next version.

Ultimately, this will allow bootable CDs for Macs (with the help of
miBoot for oldworld machines), and with a bit more GUI and the help of an
installer, we'll be, I hope, the primary bootloader for newworld Macs. I
plan to slowly abandon BootX support for those machines since it involves
too many hacks to work around various issues related to getting rid of
MacOS and problems with devices MacOS put in a non-reset state).


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Re: bootloader & head.S weirdness (patch)

[Cort Dougan]

Have you tried the rs6000 quik on the g3's?  I've heard people have had
success with the modifications I made but haven't been able to get ahold of
a g3 for long-term tests.  I'd like to combine the two if we could.

} Ok, I posted the very first version of this bootloader. I'd appreciate
} any comment, suggestion, etc... It's called "yaboot" and is on my test page
} 
} <http://calvaweb.calvacom.fr/bh40/test.html>
} 
} It's targeted for newworld machines only (machines with a working OF that
} can load ELF binaries). It has a quik-like interface.

I think Yellowdog already has their cd bootable from macs.

} Ultimately, this will allow bootable CDs for Macs (with the help of
} miBoot for oldworld machines), and with a bit more GUI and the help of an
} installer, we'll be, I hope, the primary bootloader for newworld Macs. I
} plan to slowly abandon BootX support for those machines since it involves
} too many hacks to work around various issues related to getting rid of
} MacOS and problems with devices MacOS put in a non-reset state).

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Re: bootloader & head.S weirdness (patch)

[Benjamin Herrenschmidt]

On Tue, Nov 23, 1999, Cort Dougan <cort@fsmlabs.com> wrote:

>Have you tried the rs6000 quik on the g3's?  I've heard people have had
>success with the modifications I made but haven't been able to get ahold of
>a g3 for long-term tests.  I'd like to combine the two if we could.

rs6000 quik is quik2.0 in ELF package ? I think I tried it but i failed
finding the boot device. I'll look at it again tomorrow.

When I tried to do what quik does in my bootloader (memmove'ing the
kernel to 0 before booting it), I ended up in a default catch. On the new
Macs, OF doesn't seem to map all the memory by default and won't let you
claim low-memory vectors so easily. I managed to map them without doing a
claim, but I had then problems instanciating RTAS from the kernel then.
Also, quik lacks support for the initrd. Since BootX doesn't work on the
new iMac DV (and I may not find a fix soon, it's a weird problem with
MacOS shutdown), there is need for an OF bootloader with initrd support
for installing on those machines.
(kernel with piggyback initrd may work too, but I heard of several people
who failed building them, so I added an option to load it from a separate
file).

Basically, my bootloader contains bits of quik, bits of poof, and a
simple abstract mecanism for ading file systems to it (currently, only
ext2 is built-in, iso will come soon and I'm thinking about UFS for
netbsd for example). Once it works, I plan to make it graphical with some
way to "detect" the possible boot devices (I already have an almost
working algorithm for that).

>I think Yellowdog already has their cd bootable from macs.

I discussed with them about this and they didn't manage to make this
work. The mini-ISO filesystem I'll add to yaboot comes from them. I'll do
more tests with CDs later, when we have a definitive solution to those
kenrel entry problems.

>} Ultimately, this will allow bootable CDs for Macs (with the help of
>} miBoot for oldworld machines), and with a bit more GUI and the help of an
>} installer, we'll be, I hope, the primary bootloader for newworld Macs. I
>} plan to slowly abandon BootX support for those machines since it involves
>} too many hacks to work around various issues related to getting rid of
>} MacOS and problems with devices MacOS put in a non-reset state).

Did you had a chance to test my new head.S/prom.c patch ? 


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bootable CD's (Re: bootloader & head.S weirdness (patch))

[Hollis R Blanchard]

On Tue, 23 Nov 1999, Cort Dougan wrote:
> 
> } Ultimately, this will allow bootable CDs for Macs (with the help of
> } miBoot for oldworld machines), and with a bit more GUI and the help of an
> } installer, we'll be, I hope, the primary bootloader for newworld Macs. I
> } plan to slowly abandon BootX support for those machines since it involves
> } too many hacks to work around various issues related to getting rid of
> } MacOS and problems with devices MacOS put in a non-reset state).
> 
> I think Yellowdog already has their cd bootable from macs.

That's TurboLinux. And they use miBoot.

-Hollis


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Re: bootable CD's (Re: bootloader & head.S weirdness (patch))

[Benjamin Herrenschmidt]

On Tue, Nov 23, 1999, Hollis R Blanchard <hollis+@andrew.cmu.edu> wrote:

>That's TurboLinux. And they use miBoot.

Yes, but miBoot is a BootX derivative and works only on old-world macs
(with MacOS ROM in real ROM). 


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Re: bootable CD's (Re: bootloader & head.S weirdness (patch))

[Dan Burcaw]

Hollis,

> That's TurboLinux. And they use miBoot.

We have new world rom bootable cds in-house and have for some time.
Not using miBoot, but our own mods to quik. Note: there were issues with
the bootable cds we tried and that info has been passed to Ben in hopes
that the new bootloader solves them.

Dan

Terra Soft Solutions, Inc.
   Yellow Dog Linux
   "The Ultimate Companion for a Dedicated Server"
   http://www.yellowdoglinux.com/


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