[PATCH RFC 0/3] arm64: disable/enable d-cache support for

[Pratyush Anand]

On Thursday 07 May 2015 09:55 AM, AKASHI Takahiro wrote:
> Geoff, Pratyush
>
> On 05/07/2015 02:37 AM, Pratyush Anand wrote:
>> Hi Geoff,
>>
>> On Wednesday 06 May 2015 10:35 PM, Geoff Levand wrote:
>>> Your 2 minutes seems like a long time.  Is this seen on other platforms?
>>
>> At least it is seen on two different HW platforms I had tested with. I
>> do not know about other.
>>
>> It would be nice if somebody else who is using kexec on HW platform
>> can report their execution time.
>
> On my HW, it took about 42secs before showing extra boot messages after
> "I'm in purgatory."
>

It would also depend on the size of different segments (mainly kernel 
and initrd) on which sha256 is calculated. What are the size of binaries 
in your case?

In my case:

segment[0].memsz = 0x10e0000 // kernel
segment[1].memsz = 0x1910000 // initrd
segment[2].memsz = 0x10000   // dtb
segment[3].memsz = 0x40000   // purgatory, not included in sha256
segment[4].memsz = 0x10000   // elf core hdr

@Geoff: Do you see any specific side effect for enabling D-cache in 
purgatory, other than the fact that it increases size of purgatory? May 
be we can keep an user option to select/not select d-cache enabling.