[PATCH] arm: relocate: Introduce data-only relocation mode

[Marek Vasut]

On 3/16/26 3:50 PM, Tom Rini wrote:

Hello Tom,

>> +config SKIP_RELOCATE_CODE
>> +	bool "Skips relocation of U-Boot code to end of RAM"
>> +	help
>> +	  Skips relocation of U-Boot code to the end of RAM, but still does
>> +	  relocate data to the end of RAM. This is mainly meant to relocate
>> +	  data to read-write portion of the RAM, while the code remains in
>> +	  read-only portion of the RAM from which it is allowed to execute.
>> +	  This split configuration is present on various secure cores.
> 
> Is this really configurable, or is this determined by the SoC? This
> feels like something a board should be select'ing rather than
> configuring and I do worry about boards abusing this in the same of some
> possibly dubious speed-up rather than the intented and valid use case.

On R-Car X5H, the Cortex-M core U-Boot port selects this, the Cortex-A 
core U-Boot port does NOT select this. So, this is neither SoC level 
configuration nor board level configuration, this is SoC CPU core level 
configuration. I can definitely hide this symbol and conditionally 
select it on SoC level.

> [snip]
>> diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S
>> index 6ee58f4edfe..b6a648708f4 100644
>> --- a/arch/arm/lib/relocate.S
>> +++ b/arch/arm/lib/relocate.S
>> @@ -79,6 +79,15 @@ ENDPROC(relocate_vectors)
>>   ENTRY(relocate_code)
>>   relocate_base:
>>   	adr	r3, relocate_base
>> +
>> +#ifdef CONFIG_SKIP_RELOCATE_CODE
>> +	mov r4,	#CONFIG_SKIP_RELOCATE_CODE_DATA_OFFSET
> 
> Spacing. But if there's no other comments and propmting the user is
> correct, I can fix when applying.
Fixed in V2 .