[prev in list] [next in list] [prev in thread] [next in thread] 

List:       osdl-fastboot
Subject:    [Fastboot] TODO
From:       ebiederm () xmission ! com (Eric W !  Biederman)
Date:       2004-09-19 22:18:41
Message-ID: m1wtyp7vi6.fsf () ebiederm ! dsl ! xmission ! com
[Download RAW message or body]

This is my todo list of what things I see needing to happen
with the current kexec code base.

To handle the kexec on panic case kexec-tools needs to do more.
And doing it all in assembly just to make the code PIC is a real
problem.  It appears the solution is to generate an ELF shared
library and relocate it before kexec_load is called.  This should
allows us to write checksum code generically in C, and
to handle other interesting cases..

After thinking through what it would take I can implement
32 bit compatibility on the 64 bit architectures that support it
without a lot of work.  I just need to refactor sys_kexec_load
a little bit, so I can load add an extra bit of kernel space
code.

Now that it has been shown that we can execute kernels at a
non-default memory location without a tremendous amount
of work I want to start including the kexec on panic code.
What executing code at the non-default address gives us
is the guarantee that the kernel that panic'd never used the memory
we are executing out of for DMA buffers.  Which means that
we don't have to stop on-going DMA transactions.

Hari and the rest of the folks at IBM have been doing a good
job keeping the idea of kexec on panic alive, and the code has
slowly been improving.  Unfortunately the code is not clean
enough or paranoid enough for me to feel comfortable with it
in it's current form.  So to include the functionality I believe I
will need to rewrite most of it :(  Most of what needs to happen has
already been discussed on this list and on lkml, so I won't repeat
that now.

I'm not quite certain when I will get to all of this but hopefully
I can start in the next week or so.

Since I'm not coding fast enough to show everyone what I was thinking
I figured a snapshot of my thoughts might help.

Eric


_______________________________________________
fastboot mailing list
fastboot@lists.osdl.org
http://lists.osdl.org/mailman/listinfo/fastboot


[prev in list] [next in list] [prev in thread] [next in thread]