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Re: [Xen-devel] [ARM:PATCH v2 1/1] Pass the timer clock-frequency to DOM0



Hello,

On 13/04/14 20:28, Suriyan Ramasami wrote:
On Fri, Apr 11, 2014 at 9:32 AM, Julien Grall <julien.grall@xxxxxxxxxx> wrote:
Hello,

On 04/11/2014 05:05 PM, Suriyan Ramasami wrote:
On Tue, Apr 1, 2014 at 4:12 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
On Fri, 2014-03-28 at 14:04 +0000, Julien Grall wrote:
That made me think that this is the only board with this issue. I would
definitely prefer to fix the clock frequency in U-boot. The bootloader
should respect the ARM ARM (see B.8.1.1):

"The CNTFRQ register is UNKNOWN at reset, and therefore the counter
frequency must written to CNTFRQ as part
of the system boot process."

Yes, Suriyan, please exhaust this avenue of attack (fixing u-boot on the
platform) first.

Thank you gentlemen for your comments.
The problem with this board is that the uboot is not entered in secure
mode, and hence the mcr indstruction to set the ARCH timer frequency
cannot be executed in u-boot.

If so, what is the state of the CPU when it jumps to U-boot?
The CPU has to be either in secure mode or hyp mode.
AFAIK, if it's NS you won't be able to go in hyp mode, unless crash the
CPU...

The CPU is in HYP mode when it jumps to U-boot.

I'm lost...

From my understanding (i.e what I read on the web). For your case you use a modified U-boot/SPL, right?

If so, without this modification, in which state U-boot is booting? What are the CPU states along the different bl (1,2)?

Did you try this u-boot: https://github.com/medicalwei/u-boot-odroidxu-hyp? FYI I don't have any odroid XU. I'm trying to understand

Regards,

--
Julien Grall

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