Re: [PATCH 0/2] Kexec jump: The first step to kexec base hibernation

david
2007-07-17T08:22:04Z

Ying, as the kexec guru in this thread I have a question for you about how
kexec works (and possibly where you are going with this)

for the power-off hibernate with ACPI disabled the hibernation seems
fairly straightforward (although there are still some missing pieces)

however, since the resume designed for ACPI won't work would the following
approach work

1. boot one kernel
2. setup a kexec the same way you would for hibernate
3. kexec to the new kernel
4. overwrite the memory of the first kernel
5. kexec 'back' to the main kernel that has now been overwritten by what was saved?

as part of this question, when you do a kexec, how does the kernel that
you are doing the kexec to know what to run next?

it needs to do some initialization first before it starts running normal
things, and at that point it the move back doesn't look for init like a
normal kernel boot (or the system would effectivly boot instead of picking
up where it left off)

is this 'restart point' flexible enough that either the pre-hibernate
kerenl or the small hibernate kernel could tell the pre-hibernate kernel
to go into suspend-to-ram mode before doing anything else?

Rafael,
if ACPI is disabled and not used, is there any memory in the origional
kernel that _must not_ be saved in the hibernate image? I recognise that
for efficancy it would save time to not save free memory, but if I'm
willing to waste some resources would it hurt to save everything?

David Lang