From: Peter Maydell <peter.maydell@linaro.org>
To: Alistair Francis <alistair.francis@xilinx.com>
Cc: Edgar Iglesias <edgar.iglesias@xilinx.com>,
"Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
qemu-arm <qemu-arm@nongnu.org>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH v1 2/2] target-arm: Enable EL2 for the A53s and A57s
Date: Tue, 10 May 2016 09:09:55 +0100 [thread overview]
Message-ID: <CAFEAcA84aHCj2ADGkuxEbdx1qy7scu+nXSTU5K70ZPXR2PL1Ng@mail.gmail.com> (raw)
In-Reply-To: <CAKmqyKOjOwWOp-6kzOunxf0F8c8r+ua62gxFJ6x2vJR2Yaz_Nw@mail.gmail.com>
On 10 May 2016 at 01:16, Alistair Francis <alistair.francis@xilinx.com> wrote:
> 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.
OK, that makes sense. u-boot tends to be a bit lower level and less
hardware-agnostic. I just wanted to check it wasn't caused by some
problem in QEMU's EL3 support we could easily fix.
> 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
I would be OK with any of these three from a QEMU perspective.
Fixing u-boot is probably conceptually the nicest but I've never
looked at u-boot internals so it could be simple or painful...
Edgar, do you have the list of what we're still missing before we
can turn on EL2?
thanks
-- PMM
next prev parent reply other threads:[~2016-05-10 8:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-06 18:10 [Qemu-devel] [PATCH v1 0/2] target-arm: Add support for HSTR_EL2 Alistair Francis
2016-05-06 18:11 ` [Qemu-devel] [PATCH v1 1/2] target-arm: Add the HSTR_EL2 register Alistair Francis
2016-05-13 17:46 ` Peter Maydell
2016-05-13 20:39 ` Alistair Francis
2016-05-06 18:11 ` [Qemu-devel] [PATCH v1 2/2] target-arm: Enable EL2 for the A53s and A57s Alistair Francis
2016-05-06 22:25 ` Peter Maydell
2016-05-07 1:51 ` Edgar E. Iglesias
2016-05-09 16:58 ` Alistair Francis
2016-05-09 17:01 ` Peter Maydell
2016-05-10 0:16 ` Alistair Francis
2016-05-10 8:09 ` Peter Maydell [this message]
2016-05-10 10:36 ` Edgar E. Iglesias
2016-05-10 13:22 ` Peter Maydell
2016-05-10 18:18 ` Alistair Francis
2016-05-10 18:13 ` Alistair Francis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAFEAcA84aHCj2ADGkuxEbdx1qy7scu+nXSTU5K70ZPXR2PL1Ng@mail.gmail.com \
--to=peter.maydell@linaro.org \
--cc=alistair.francis@xilinx.com \
--cc=edgar.iglesias@gmail.com \
--cc=edgar.iglesias@xilinx.com \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.