[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH v1 2/2] target-arm: Enable EL2 for the A53s and

From: Alistair Francis
Subject: Re: [Qemu-devel] [PATCH v1 2/2] target-arm: Enable EL2 for the A53s and A57s
Date: Mon, 9 May 2016 17:16:51 -0700

On Mon, May 9, 2016 at 10:01 AM, Peter Maydell <address@hidden> wrote:
> On 9 May 2016 at 17:58, Alistair Francis <address@hidden> wrote:
>> I might have to look at disabling EL3 support for the ZynqMP machine
>> form the command line, as I can't boot Linux with EL3 but not EL2.
> I think it's worth trying to find out why this doesn't work:
> I'd hope that Linux can cope with a no-EL2 setup.

It is actually a u-boot problem. I originally just assumed it was a
Linux problem, but it happens before u-boot hands off to Linux.

It appears that u-boot won't work at all with EL3 enabled but EL2
disabled. It always moves to EL2 before moving to EL1 and there is no
code prepared to handle going from EL3 directly to EL1.

Just for the record, I'm specifically talking about what happens in
the do_nonsec_virt_switch() function.

It looks like there are three options:
 1. Add support to u-boot to drop from EL3 to EL1 (I'm assuming this
is possible, as not all implementations have EL2)
 2. Just wait until QEMU adds EL2 support
 3. Allow a QEMU command line option to start in EL1 instead of EL3



> thanks
> -- PMM

reply via email to

[Prev in Thread] Current Thread [Next in Thread]