[LinuxBIOS] ELF loader in v3

Jordan Crouse jordan.crouse at amd.com
Fri Jun 29 21:25:42 CEST 2007

On 29/06/07 20:56 +0200, Stefan Reinauer wrote:
> Jordan's talk here at the OLS described how LinuxBIOS relocates itself
> from the very low space to TOM during the boot process. I think we
> should think carefully about this stuff. Will any OS ever claim to be
> copied into the low 1M?

Eric can correct me, but from what I can tell, the intent of the extra
copy is to allow any arbitrary application to run - even those that are less
then responsible about where they go in memory.  We generalized a little
bit in our talk - what happens in reality in the elf loader is that parts of
the payload that would interfere with the loader are copied into a temporary
buffer, and later, LB copies itself out of the way, and replaces the 
missing chunks back into their rightful place.  I don't believe this code
runs all the time - just in those situations where LB code is at danger.

Its a little hackish, but I would prefer to have that rather then put
restrictions on the payload - we can hope that most payloads are friendly,
but we shouldn't restrict the ones that aren't.

Jordan Crouse
Senior Linux Engineer
Advanced Micro Devices, Inc.

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