Subject: Re: [PATCH] Support for relocatable kdump kernel

From: Mohan Kumar M <[email-masked]>
Date: Tue, 21 Oct 2008 23:51:48 +0530

Michael Ellerman wrote:

> Does it? I see CONFIG_CRASH_DUMP depending on PPC64, so there is no
> 32-bit kdump possible. Or is someone working on it out-of-tree?
> 

IIUC Anton Vorontsov is working on the 32-bit kdump kernel support.

>> Do you expect a function to do the checking in iommu.c?
> 
> You'd use the function in iommu.c, but it should be defined in some
> header.
> 
Yeah, I will do that.

> OK. Does old purgatory ensure that the register is 0? Otherwise I think
> it's possible that a new kernel could get confused by cruft left in that
> register by an old purgatory - causing the 2nd kernel to think it's a
> kdump kernel when it shouldn't be.

__kdump_flag is by default is 0 and old purgatory code even won't know 
that it need to modify __kdump_flag. So unless __kdump_flag is 1, the 
kernel will behave as a normal one.

Regards,
Mohan.