Re: [PATCH] ia64, kexec: allow base of crashkernel to be auto-discovered

From: Zou Nan hai <>
Date: 2006-06-29 08:38:22
On Wed, 2006-06-28 at 19:00, Horms wrote:
> The crashkernel command line parameter accepts a size and base address for
> the memory region that is reserved to be used as the memory space for a
> crash kernel. At this time, on some architectures, notably i386 and x86_64,
> the base address of the crash kernel needs to be modified at compile time
> to match the base address passed to crashkernel. However, on ia64 the
> crash kernel does not need to be relocated at compile time, thus
> there the base address of the crashkernel region does not need to be fixed.
> This patch allows the base address of crashkernel to be determined at boot
> time if the base address passed on the command line is 0. Otherwise
> the specified base address will be used, as is currently the case.
> The advantage is that the region layout may vary from machine to machine,
> and finding a place for the crashkernel is a manual process. This eliminates
> that manual work, and I expect will make life slightly easier for distros.
> I would like to note that currently it will try and place the crashkernel
> region inside the first "System RAM" region that has space. I am not
> sure if there should be a lower or upper bond on the crashkernel base address,
> but it will be trivial to add to the arguments passed to allocate_region()
> if necessary.
  I think there is no upper and lower limit of crash kernel base
address, but the base address should be aligned to 64M.

which is max(max possible IA64_GRANULE_SIZE, KERNEL_TR_PAGE_SIZE)

> Signed-Off-By: Horms <>
>  arch/ia64/kernel/efi.c |   37 +++++++++++++++++++++++++++++++++----
>  1 file changed, 33 insertions(+), 4 deletions(-)
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Received on Thu Jun 29 10:24:50 2006

This archive was generated by hypermail 2.1.8 : 2006-06-29 10:25:03 EST