[RFC PATCH] Kbuild: Always use $(PHASE_)

[Simon Glass]

Hi Tom,

On Wed, 5 Mar 2025 at 08:49, Tom Rini <trini at konsulko.com> wrote:
>
> On Wed, Mar 05, 2025 at 07:15:50AM -0700, Simon Glass wrote:
> > Hi Tom,
> >
> > On Tue, 4 Mar 2025 at 13:41, Tom Rini <trini at konsulko.com> wrote:
> > >
> > > It is confusing to have both "$(PHASE_)" and "$(XPL_)" be used in our
> > > Makefiles as part of the macros to determine when to do something in our
> > > Makefiles based on what phase of the build we are in. For consistency,
> > > bring this down to a single macro and use "$(PHASE_)" only.
> > >
> > > Signed-off-by: Tom Rini <trini at konsulko.com>
> > > ---
> > > Cc: Simon Glass <sjg at chromium.org>
> > >
> > > This leads a little bit of dead code in scripts/Makefile.xpl that I
> > > didn't remove as this is an RFC. This also omits expanding on our build
> > > documentation slightly.
> > >
> > > With the following patches applied (which are correct regardless of this
> > > RFC and so separate):
> > > https://patchwork.ozlabs.org/project/uboot/patch/20250304203235.2834031-1-trini@konsulko.com/
> > > https://patchwork.ozlabs.org/project/uboot/patch/20250304202436.2783784-1-trini@konsulko.com/
> > >
> > > There's no change in the resulting build before/after this patch.
> > >
> > > We could do the other direction and drop $(PHASE_) in favour of $(XPL_)
> > > but that would require updating the logic of how XPL_ is defined.
> >
> > These are not the same thing at present:
> >
> > XPL_ refers to any xPL phase
> > PHASE_ refers to a particular xPL phase
> >
> > Since it doesn't change the build, it must be fine. It's just surprising, to me.
>
> Erm, this is what we have in scripts/Makefile.xpl today:
>
> ifdef CONFIG_XPL_BUILD
> XPL_ := SPL_
> ifeq ($(CONFIG_VPL_BUILD),y)
> PHASE_ := VPL_
> else
> ifeq ($(CONFIG_TPL_BUILD),y)
> PHASE_ := TPL_
> else
> PHASE_ := SPL_
> endif
> endif
> else
> XPL_ :=
> PHASE_ :=
> endif
>
> Which is why I sent the two fixes first, for places that relied on
> CONFIG_SPL_FOO=y in a TPL (PowerPC and their spl->tpl->U-Boot chain) or
> VPL (sandbox didn't set TPL_DM_I2C but did set SPL_DM_I2C) phase of the
> build.

OK. I believe this means that we won't be able to say 'build this for
any xPL' without adding a separate Kconfig for each phase where we
want it enabled. Is that right?

If so, that's fine with me and I would prefer it.

Regards,
Simon