On Fri, Jul 05, 2013 at 11:30:01AM -0400, Jon Masters wrote:
On 07/05/2013 05:07 AM, Richard W.M. Jones wrote:
> On Wed, Jul 03, 2013 at 11:59:28AM -0500, Jon wrote:
>> I'm pleased to announce the availability of Fedora 19 for the 2012 Samsung
>> Chromebook featuring ARM Exynos dual core A15 processor.
>
> Sorry to slightly hijack this thread. I will try your remix later.
>
> Reading the comments on
https://lwn.net/Articles/557132/#Comments
> it seems as if the news on KVM on the Chromebook is not good. It
> doesn't boot into HYP mode, and there's no way to make it boot into
> HYP mode, so KVM won't be supported. Is that right?
That's roughly what I'd expect to be the case. There might be a signed
U-Boot someone has hacked that does enable HYP mode, but otherwise I
suspect you're out of luck. I'll ask around during Linaro Connect.
I asked about this on #kvm-arm earlier today and got this long reply:
11:58 < rwmjones> I'm reading a comment here:
11:58 < rwmjones>
https://lwn.net/Articles/557561/
11:58 < rwmjones> which suggests that KVM on the Samsung Chromebook 2012 (ARM A15
version) isn't possible because the
bootloader doesn't boot into HYP mode
11:58 < rwmjones> is this true? if so is there a way around it?
11:59 < pm215> IIRC the bootloader gets control in secure-SVC
11:59 < pm215> it is from there possible to get to NS-HYP
11:59 < pm215> it's just that the stock bootloader doesn't do this before
booting the kernel
11:59 < rwmjones> so what's involved in making it work?
11:59 < pm215> somebody needs to write some code and get it into the bootloader
12:00 < rwmjones> ok, and the bootloader can be replaced (next comment down suggests
this requires soldering)?
12:01 < pm215> I believe this to be true, though I don't have a chromebook
12:01 < pm215> I think you get the google bootloader to chain boot some other
bootloader which you do have control of, and then
that can actually boot your os
12:02 < suihkulokki> or maybe we could just prepend some code in front of the kernel
zimage that switches to HYP mode?
12:02 < pm215> nope
12:02 < suihkulokki> damn
12:02 < pm215> we spent quite a long time being very firm that the ABI here is
"bootloader's job to get this right"
12:03 < pm215> there are some u-boot patches currently going through code review to
do the go-to-hyp-mode thing properly for
arndale
12:03 < pm215> hopefully if they get upstream it will be more straightforward to say
"ok, I have $other-board and it needs to
do this too"
12:05 < apritzel> which would require that the Chromebook u-boot support is upstream
as well
12:05 < apritzel> AFAIK this is not the case currently
[There's more of this, but that seems to cover the main points]
Reading around this, it does seem as if it's possible to get from
secure SVC to HYP (although not easy).
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
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