On 10/31/14 at 04:25pm, Geoff Levand wrote:

Hi Dave,

Thanks for testing.

On Fri, 2014-10-31 at 15:52 +0800, Dave Young wrote:

quoted

I tested your patches. The macihne is using spin-table cpu enable method
so I tried maxcpus=1 as you suggested.

There's below issues for me, thoughts?

1. For acpi booting there's no /proc/device-tree so kexec can not find dtb
to use.

You can supply a DTB with the kexec --dtb option, then kexec will not need
/proc/device-tree.  Please try if you can and let me know what happens.

I remember I tried but kexec load fails due to kexec-tools is still trying to
access proc flattened dtb. I have little time last few days, will test it again
to confirm. 

quoted

2. adding "acpi=off" to 1st kernel boot cmdline, kexec load fails with error
like below:
machine_apply_elf_rel: ERROR Unknown type: 261

I did below hack then kexec load works fine, 

OK, thanks, I'll add support for R_AARCH64_PREL32 in.

quoted

but `kexec -e` still does not work
there's nothing more than "Disableing non-boot CPUS ...\n Bye!":

It is really tough to say what happened.  The 'Bye!' message is printed
just before the 1st stage kernel exits and the 2nd stage kernel is
entered.  If you have a debugger you can put some breakpoints in
there to see how far it gets.  That is generally how I figure out
what went wrong.

You could try the kexec --lite option, it will do a non-purgatory
boot.

You could also try my master branch that has more debugging output.
Some of it is through the VE's serial port, so you may need to
change that to what your platform has.

I think I have will have to check if I can find a way to debug as you
have done in your master branch.

Thanks a lot
Dave