[U-Boot] When to create a SoC directory for ARM

[Scott Wood]

On Thu, 2013-09-26 at 12:57 -0700, York Sun wrote:
> On 09/26/2013 12:55 PM, Scott Wood wrote:
> > On Thu, 2013-09-26 at 12:48 -0700, York Sun wrote:
> >> On 09/26/2013 12:46 PM, Sharma Bhupesh-B45370 wrote:
> >>>
> >>>> -----Original Message-----
> >>>> From: u-boot-bounces at lists.denx.de [mailto:u-boot-bounces at lists.denx.de]
> >>>> On Behalf Of Scott Wood
> >>>> Sent: Friday, September 27, 2013 12:53 AM
> >>>> To: FengHua
> >>>> Cc: trini; sun york-R58495; u-boot
> >>>> Subject: Re: [U-Boot] When to create a SoC directory for ARM
> >>>>
> >>>> On Thu, 2013-09-26 at 13:23 +0800, FengHua wrote:
> >>>>> all SOC specific include file should be in
> >>>>> arch/arm/include/asm/arch-SOC/ or some common directory(like
> >>>>> include/asm/imx-common). Currently, u-boot only link SOC
> >>>>> specific(arch-SOC) include directory.
> >>>>> You could touch a mmu.h file in arch/arm/include/asm/arch-ls2/ and
> >>>>> include arch/arm/include/asm/arch-armv8/mmu.h.
> >>>>> or move arch-armv8/mmu.h to arch/arm/include/asm/ to make it as a
> >>>>> generic file.
> >>>>> Maybe we should distinguish architecture specific include directory
> >>>>> and SOC  specific include directory.
> >>>>
> >>>> Is the XXX arch-XXX supposed to be an SoC family or a CPU
> >>>> family/architectutre?
> >>>>
> >>>
> >>> Usually in 'arch/arm/include/asm' we have both:
> >>> - arch-armv7 (Arch specific. Houses stuff common to ARMv7 CPU, e.g. Global timer, SP805 WDT..)
> >>> - arch-mx6 (SoC family specific. Houses stuff like SoC specific IOMUX pads..)
> > 
> > Which one does "#inculde <asm/arch/foo.h>" refer to?
> > 
> 
> arm/arch is a symbolic link created at compiling time. It points to
> arm/arch-$(soc), if $(soc) is not defined, then it points to
> asm/arch-$(arch). That's my understanding.

How is that supposed to work when both arch-$(soc) and arch-$(arch) are
present?  Why are SoC and CPU arch confused in this way?

-Scott