Re: [PATCH] x86/intel/quark: Remove lock bit around kernel IMR
From: Andy Shevchenko
Date: Fri Jan 22 2016 - 07:11:41 EST
On Fri, Jan 22, 2016 at 1:08 PM, Bryan O'Donoghue
> On Thu, 2016-01-21 at 20:44 +0200, Andy Shevchenko wrote:
>> On Thu, Jan 21, 2016 at 4:05 PM, Bryan O'Donoghue
>> <pure.logic@xxxxxxxxxxxxxxxxx> wrote:
>> > The solution to this situation is to keep the kernel .text section
>> > IMR lock
>> > bit false. This means that a subsequent kernel will boot and can
>> > tear-down
>> > an existing IMR, while still setting up an IMR around its own .text
>> > section.
>> Like I said you privately it would be nice to have a knob how to
> Ok - that can work. The default ought to be !locked and we can
> parametrize a different behaviour.
>> My idea is to provide kernel command line imr= and supply imr=lock
>> when user wants to boot kernel locked.
>> Optionally: add a warning if imr=lock and kernel build with kexec
>> might bring issues
> This makes sense.
>> Optionally: add a kernel config option to boot always in locked mode
>> (should depend on !KEXEC)
> Meh. You can still force the state you want with the parameter though.
> I reckon we should skip this change for now.
P.S. Please, use my @linux.intel.com address in the tags.
With Best Regards,