Re: [RFC] x86 ELF bootable kernels/Linux booting Linux/LinuxBIOS

H. Peter Anvin
2002-02-03T19:49:10Z

Eric W. Biederman wrote:

>
> O.k. I have been thinking about this some more, and I have come up with a couple
> alternate of solutions.
>
> The simplest is the observation that right now 10MB is about what it
> takes to hold every Linux driver out there. So all you really need is
> a 16MB system, to avoid a device probing loader. And probably
> noticeably less than that. The only systems I see having real
> problems are old systems where device enumeration is not reliable, and
> require human intervention anyway.
>
> A second is to just make certain there is some kind of fallback path
> so if the image is too large have a way to load a smaller one. When
> you consider that older systems had less memory it has a reasonable
> chance of working properly.
>
> My final and favorite is to take an ELF image, define a couple of ELF
> note types, and add a bunch those notes saying which pieces are
> hardware dependent. So a smart ELF loader can prune the image as it
> is loaded, and a stupid one will just attempt to load everything. And
> with the setup for this not being bootloader specific it will probably
> encourage device pruning loaders.
>
> Am I being optimistic or are there any pressing cases for callbacks to
> the firmware?
>

Ok, now let me ask the question that hopefully should be obvious to
everyone now...

WHAT'S THE POINT?

All you're doing is an awfully complex song and dance to *avoid*
implementing a solution that, while imperfect, is thoroughly established
and has worked for 20 years.

-hpa