From mboxrd@z Thu Jan  1 00:00:00 1970
From: cw00.choi@samsung.com (Chanwoo Choi)
Date: Tue, 10 Mar 2015 10:31:03 +0900
Subject: [PATCH v5 1/9] arm64: dts: exynos: Add dts files for 64-bit
 Exynos5433 SoC
In-Reply-To: <54F99B1A.3080600@samsung.com>
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Message-ID: <54FE4957.7050904@samsung.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Mark,

On 03/06/2015 09:18 PM, Chanwoo Choi wrote:
> Hi,
> 
> On 03/06/2015 08:40 PM, Mark Rutland wrote:

[snip]

>>
>>>>>>>> I take it CPUs boot at EL2?
>>>>>>
>>>>>> Do the CPUs boot at EL1 or EL2?
>>>>>
>>>>> Unfortunately, I cannot check the secure firmware for Exynos5433 SoC.
>>>>> I think that a few SoC provider probably would know it.
>>>>
>>>> I guess I asked the wrong question.
>>>>
>>>> Do CPUs enter the kernel at EL2 or at EL1?
>>>
>>> Could you give me a tip how to check the kernel at EL2 or EL1?
>>
>> Hmm... I thought we logged this but it looks like we don't.
>>
>> You could hack in a check of is_hyp_mode_available() and
>> is_hyp_mode_mismatched(). That will tell you if EL2/hyp is available,
>> and whether all CPUs enter at the same mode (mandatory per the boot
>> protocol).
> 
> OK, I'll try it.

I check the return value of is_hyp_mode_available() to catch whether EL1 or EL2. 

The is_hyp_mode_available() returns 'false' during kernel booting.
- __boot_cpu_mode[0]: 0xe11 (BOOT_CPU_MODE_EL1)
- __boot_cpu_mode[1]: 0x0

Best Regards,
Chanwoo Choi