[PATCH 1/6] arm: mach-k3: Add default ATF location for AM62/AM62a

[Andrew Davis]

On 6/19/24 1:20 PM, Nishanth Menon wrote:
> On 17:19-20240619, Dhruva Gole wrote:
>> Hi,
>>
>> On Feb 14, 2024 at 10:30:04 -0600, Andrew Davis wrote:
>>> There is a default ATF load address that is used for devices that have
>>> ATF running in SRAM. For AM62 and AM62a, ATF runs from DRAM. Instead
>>> of having to override the address in every defconfig, make add a
>>> default for these ATF in DRAM devices.
>>>
>>> Signed-off-by: Andrew Davis <afd at ti.com>
>>> ---
>>>   arch/arm/mach-k3/Kconfig               | 5 +++--
>>>   configs/am62ax_evm_a53_defconfig       | 1 -
>>>   configs/am62x_beagleplay_a53_defconfig | 1 -
>>>   configs/am62x_evm_a53_defconfig        | 1 -
>>>   configs/phycore_am62x_a53_defconfig    | 1 -
>>>   configs/verdin-am62_a53_defconfig      | 1 -
>>>   6 files changed, 3 insertions(+), 7 deletions(-)
>>>
>>
>> Beagleplay stops booting completely with latest U-boot so I did a little
>> bisect and it seems like reverting this patch helps.
>>
>> I am not sure what other implications there are of reverting this so I
>> don't suggest immediately dropping it, however some hints around what's
>> missing on beagleplay vs other platforms would be helpful.
>>
>> Because other platforms based off the same SoC don't seem to be
>> affected.
> 
> Grumble... I had to rediscover this in parallel as well - Thanks Dhruva.
> mkimage -l tispl.bin and comparing with kernel log of reserved mem
> had me completely confused.
> 
> a) Memory maps are already notorious to manage on complex heterogenous
>    systems. From beagle perspective, we have no need to go and monkey
>    with DT defined memory map and DT should be the default and modifying

Your DT source file is wrong, ATF is at 0x8000_0000 (or any address one
wants to put in K3_ATF_LOAD_ADDR). DT doesn't "define" hardware, it "describes"
it. ATF's location is dynamic and configurable, it doesn't belong in DT.

You have two options, either go update your DT, then update it again every
time ATF moves. *OR* simply turn on OF_SYSTEM_SETUP and let U-Boot add the
correct location reserved memory node for you.

Then you can also drop out the reserved-node from the DT template file.
Only U-Boot knows where ATF is really placed in RAM, so U-Boot must add
this info to DT.

>    DT should be explicitly called out with a log (instead of done
>    "transparently") - so instead of CONFIG_K3_OPTEE_LOAD_ADDR default
>    being forced from u-boot, it should be made optional, where when
>    defined, it can overide the dt definition or some variant of that.
> 
> b) Looks like
>     https://lore.kernel.org/u-boot/20240214163009.983034-4-afd@ti.com/
>     missed beagleplay? and we were in for a surprise there - i dont want

This was the only miss, OF_SYSTEM_SETUP didn't get added to the beagleplay
config. Bryan just sent the fix for that now. I'll go look for a way to
make this common across the whole SoC family so we don't again miss any
new boards.

Andrew

>     to switch from default dts for beagleplay to something different just
>     because of simplicity for users to know exactly the carveouts and
>     with other s/w starting up on uC, dts is our "canonical truth".
>