[PATCH 02/88] treewide: Correct invalid Kconfig syntax and warnings

[Alexey Brodkin]

Hi Tom, Daniel, all,

> On 1/27/23 14:45, Tom Rini wrote:
> > On Mon, Jan 23, 2023 at 02:59:05PM -0700, Simon Glass wrote:
> >
> >> In several places a 'select' is used to select a choice, which is not
> >> supported by Kconfig. In other places, the filename for the 'source'
> >> command is not in quites.
> >>
> >> Fix these two problems throughout the tree, so that kconfiglib does not
> >> show any more warnings.
> >>
> >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >
> > OK, to summarize what I just said in another email and clarify future
> > work. Please first split this patch in to its own series that corrects
> > each type of problem, per commit. The missing quotes for example, and
> > then the extra whitespace ones. Next, commenting out a select is wrong,
> > and each case needs to be better understood / fixed. I'm honestly not
> > sure if asking endianness for MIPS is right and if we should select that
> > from boards too, like ARC, but probably. The ARC_MMU one also should
> > just not be asked, I suspect, but as a separate patch where you cc
> > Alexey, we'll find out :)  And so on, for each.  Thanks.
> >

Sorry for not chiming-in sooner, but I'm here now ;)

> For MIPS the endianess (and also architecture/ISA level) needs to be able to be set
> by the user via menuconfig as most MIPS cores or SoCs can support multiple variants.
> The idea is that the specific SoC or machine just sets the supported options to
> restrict the options the user can choose. The board's defconfig should set the
> required default value for each option but must not *select* it.
> 
> See the Boston board for example:
> 
> config TARGET_BOSTON
>         bool "Support Boston"
>         ...
>         select SUPPORTS_BIG_ENDIAN
>         select SUPPORTS_CPU_MIPS32_R1
>         select SUPPORTS_CPU_MIPS32_R2
>         select SUPPORTS_CPU_MIPS32_R6
>         select SUPPORTS_CPU_MIPS64_R1
>         select SUPPORTS_CPU_MIPS64_R2
>         select SUPPORTS_CPU_MIPS64_R6
>         select SUPPORTS_LITTLE_ENDIAN
> 
> 
> 
> A possible fix for ARC could be:

To be honest I don't quite understand what's a problem which we try to fix here
and so it's not clear what to advise.

ARC cores as opposed to MIPS are configured in IP design process and so
if a particular chip is designed as little-endian and already produced in
silicon, it cannot be turned into big-endian.

Still ARCompact (AKA ARCv1) & ARCv2 processors could be configured as either
little- or big-endian, thus we used to support both variants in U-Boot.
And it's still there, so hopefully we may keep it.

> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -53,8 +53,6 @@ config ARC
>          select SUPPORT_OF_CONTROL
>          select SYS_CACHE_SHIFT_7
>          select TIMER
> -       select SYS_BIG_ENDIAN if CPU_BIG_ENDIAN
> -       select SYS_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
>  
>   config ARM
>          bool "ARM architecture"
> @@ -490,7 +488,7 @@ endif
>  
>   source "board/keymile/Kconfig"
>  
> -if MIPS || MICROBLAZE
> +if MIPS || MICROBLAZE || ARC
>  
>   choice
>          prompt "Endianness selection"
> @@ -502,11 +500,11 @@ choice
>  
>   config SYS_BIG_ENDIAN
>          bool "Big endian"
> -       depends on (SUPPORTS_BIG_ENDIAN && MIPS) || MICROBLAZE
> +       depends on (SUPPORTS_BIG_ENDIAN && MIPS) || MICROBLAZE || (CPU_BIG_ENDIAN && ARC)
>  
>   config SYS_LITTLE_ENDIAN
>          bool "Little endian"
> -       depends on (SUPPORTS_LITTLE_ENDIAN && MIPS) || MICROBLAZE
> +       depends on (SUPPORTS_LITTLE_ENDIAN && MIPS) || MICROBLAZE || (CPU_LITTLE_ENDIAN && ARC)
>  
>   endchoice
> 
> 
> 
> A *make savedefconfig* should than automatically add *CONFIG_SYS_LITTLE_ENDIAN=y* or
> *CONFIG_SYS_BIG_ENDIAN=y* to the ARC board defconfig's.

That proposal looks reasonable and allows to keep existing code as it is,
but can we just have only 1 config option which is used for endianess selection?
I.e. why having both "SYS_BIG_ENDIAN" & "CPU_BIG_ENDIAN"?

-Alexey