Re: GRUB2 Sparc

[Marco Gerards <metgerards@student.han.nl>]

Bart Grantham <bart-grubdevel@bartgrantham.com> writes:

>>>Is this to say that an f-code bootsector is underway (or maybe even
>>>complete)?
>> At the moment only Vincent is working on the sparc specific part of
>> GRUB 2.  I think making GRUB 2 actually useful on the sparc is of
>> higher priority to him (for example writing a linux loader).  Would
>> you like to help us writing a f-code bootsector?
>
> Well, I did halfway learn Forth a couple years ago in an attempt to
> port my hobby OS over to sparc, and I have both an Ultra 5 and a
> Blue&White Mac G3, so I can do some cross-platform testing.  Desite
> this, I find it hard to believe I'm the most qualified of this crowd
> to do this. ;)

This crowd is not really a crowd.  There are not that many GRUB2
developers and only Vincent (AFAIK) has a sparc.  For the PPC port we
can just load an ELF binary.

> Let me think about it some.  I'd be in WAY over my head, as I haven't
> really thought through how the f-code<->grub2 interface would be
> structured.  Are there any docs or thoughts on this from the group?
> How is the direct stage1 -> stage2 process being handled on x86
> without the stage1.5 middleman?  Specifically, how are you handling
> different filesystem structures in the boot sector?

On the PC the bootblock (512 bytes) load the GRUB kernel.  This is a
binary image with a maximum size of 32KB (IIRC).  This is loaded from
a fixed location and no filesystem specific code is involved.

After this GRUB2 is loaded.  The rest of the modules are loaded from
the filesystem.

So basically you need to load some blocks to memory and jump to it.
For open firmware that means you need to pass the OF entry point to
GRUB.

--
Marco