[U-Boot] [PATCH] arm64: Juno/FVP: adjust kernel load address

[Ryan Harkin]

On 5 January 2016 at 09:48, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Mon, Jan 4, 2016 at 4:43 PM, Andre Przywara <andre.przywara at arm.com> wrote:
>
>> The default kernel load offset for an arm64 kernel is 0x80000, so
>> U-Boot takes cares of moving the loaded kernel to a matching memory
>> location just before booting it.
>> Since we run with caches off, this takes a while for any decently
>> sized kernel - with no output explaining the reason for the delay
>> (unless one uses a DEBUG build).
>> By adjusting the default load offset for Juno and VFP to be 512K
>> aligned in the first place we can skip this copying and boot much
>> faster.
>> Tested on Juno.
>>
>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>
> Pretty cool. Almost deserves a comment directly in the config
> file so people don't screw up the geniusness :)
>

And I tested it on Juno.  At first I didn't notice much difference,
but then I actually timed it and it ~halves the time to get the kernel
started from 9 secs to about 4 or 5 secs on my R0 board (after hitting
enter on "run bootcmd").

I didn't test the FVP change because I always use the DRAM config and
I'm not set up to test semihosting.  However, the DRAM config already
has this change, so I'm confident it's the right thing to do.

> Reviewed-by: Linus Walleij <linus.walleij at linaro.org>
Tested-by: Ryan Harkin <ryan.harkin at linaro.org>

>
> Yours,
> Linus Walleij