Hi Paul,

I can't boot zImage with your patches. I'm getting the following error 
message from prom_init.c

Error: You can't boot a kdump kernel from OF!

This is due to the check:
if (PHYSICAL_START > 0)
             prom_panic("Error: You can't boot a kdump kernel from OF!\n");

where PHYSICAL_START is kernstart_addr, and this variable needs to be 
referred through RELOC macro

But even after commenting the above check, I am not able to boot zImage.

<snip boot message>

Building dt structure...
Device tree strings 0x0000000002ce4000 -> 0×0000000002ce5034
Device tree struct 0×0000000002ce6000 -> 0×0000000002cf0000
Calling quiesce …
returning from prom_init

<snip>

and the system hangs

It has CONFIG_RELOCATABLE set, (CONFIG_CRASH_DUMP is not set).

I even tried booting zImage through netboot, it also fails at the same 
place.

If you need, I can give the .config I use.

Regards,
Mohan.

Paul Mackerras wrote:

The following series of patches implement support for a relocatable
kernel by building it as a position-independent executable (PIE).
When the linker is given the -pie flag, it creates an executable that
contains dynamic relocations which can be used to relocate the image
at boot time for any desired base address.  This patch series adds a
CONFIG_RELOCATABLE config option for 64-bit which links the kernel
with -pie and arranges to process the relocations in early boot.

With the first 4 patches applied, a relocatable kernel will still copy
itself down to real address 0.  The last patch changes things so that
a relocatable kernel will run wherever it was loaded.  This last patch
is pretty much just a proof of concept since it doesn't do anything to
ensure appropriate alignment of the base address (the base address
needs to be 16kB aligned).  We probably want to work out whether we
are a kdump kernel and run in-place if so, or copy down to 0 if not.

Paul.
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