[PATCH] arm64: renesas: Add Cortex-M33 build option to R-Car Gen5

[Marek Vasut]

On 4/23/26 10:37 AM, Quentin Schulz wrote:

Hello Quentin,

>> U-Boot can run on either the CA720 (64bit) or CM33 (32bit) core, hence 
>> this duality here. RCAR_64_CM covers the CM33 core tunables, ! 
>> RCAR_64_CM the CA720 ones.
>>
> 
> I've never seen anyone prefix the Cortex core denomination with C before 
> so it's somehow confusing me :)

C stands for Cortex, right .

>>> The main issue I have with this is that RCAR_64 doesn't mean a 64b 
>>> machine anymore, and the naming doesn't help with that.
>>
>> It covers the machines which have 64bit ARM cores in them, Gen3/4/5 
>> and RZ/G2 . Sure, those SoCs also have 32bit cores in them ...
>>
> 
> Meh, I find this unnecessarily confusing. At the very least, update the 
> comment above RCAR_64 to highlight the 64b part applies to the main 
> Cortex cores in the SoC?

The Cortex cores are equivalent, there is no real "main" core, but I did 
include the 32bit CM/CR in the code comment.

>>> I'm pretty sure in the future someone's going to make the mistake of 
>>> doing a simple CONFIG_IS_ENABLED(RCAR_64) to check if it's a 64b 
>>> machine or not.
>>
>> IS_ENABLED(CONFIG_ARM64) is what they should use .
>>
> 
> No, they'll need to do
> 
> IS_ENABLED(CONFIG_RCAR_64) && IS_ENABLED(CONFIG_ARM64)

IS_ENABLED(CONFIG_ARM64) is enough to determine whether this is arm64 
build, why wouldn't it be ?

[...]

>>> Should that be a symbol instead? Then you can have
>> No, this is not user configurable, this is hardware IP address.
>>
> 
> The symbols don't need to be visible to the user.
They are not configuration symbols, they are hardware addresses, they 
have no place in Kconfig.