[U-Boot] [PATCH v2 1/7] tegra: Rework Tamonten support

[Allen Martin <amartin@nvidia.com>]

On Mon, Jun 11, 2012 at 02:29:59AM -0700, Thierry Reding wrote:
> * PGP Signed by an unknown key
> 
> * Stephen Warren wrote:
> > Allen Martin <amartin@nvidia.com> wrote:
> > >On Fri, Jun 08, 2012 at 10:28:57PM -0700, Stephen Warren wrote:
> > >> On 06/08/2012 03:27 PM, Allen Martin wrote:
> > >> > On Fri, Jun 08, 2012 at 02:07:25PM -0700, Stephen Warren wrote:
> > >> >> On 06/08/2012 02:01 PM, Allen Martin wrote:
> > >> >>> On Fri, May 25, 2012 at 06:46:22AM -0700, Thierry Reding wrote:
> > >> >>>> This commit uses the common Tegra board implementation instead
> > >of
> > >> >>>> duplicating a lot of the code. In addition, the Plutux and
> > >Medcom
> > >> >>>> specific board files can be removed as the MMC/SD setup is
> > >common
> > >> >>>> among all Tamonten-based boards.
> > >> >>>>
> > >> >>>> ...
> > >> >>>> diff --git a/board/avionic-design/medcom/Makefile
> > >b/board/avionic-design/medcom/Makefile
> > >> >>>> index b0c318c..d96d043 100644
> > >> >>>> --- a/board/avionic-design/medcom/Makefile
> > >> >>>> +++ b/board/avionic-design/medcom/Makefile
> > >> >>>> @@ -26,12 +26,12 @@
> > >> >>>>  include $(TOPDIR)/config.mk
> > >> >>>>
> > >> >>>>  ifneq ($(OBJTREE),$(SRCTREE))
> > >> >>>> -$(shell mkdir -p $(obj)../common)
> > >> >>>> +$(shell mkdir -p $(obj)../common $(obj)../../nvidia/common)
> > >> >>>>  endif
> > >> >>>>
> > >> >>>>  LIB    = $(obj)lib$(BOARD).o
> > >> >>>>
> > >> >>>
> > >> >>> This breaks with my patchset to split out the arm7 code to an SPL
> > >> >>> because even though SRCDIR and OBJDIR are the same, in the SPL
> > >build
> > >> >>> $(obj) is a subdir of $(SPLTREE) not $(OBJTREE) (not my doing).
> > >> >>>
> > >> >>> How about the following instead which seems more to the point:
> > >> >>>
> > >> >>> ifeq ($(wildcard $(obj)../common),)
> > >> >>> $(shell mkdir -p $(obj)../common)
> > >> >>> endif
> > >> >>> ifeq ($(wildcard $(obj)../../nvidia/common),)
> > >> >>> $(shell mkdir -p $(obj)../../nvidia/common)
> > >> >>> endif
> > >> >>
> > >> >> Maybe I'm just not reading it right, but isn't that just running
> > >the
> > >> >> exact same mkdir commands, just splitting it into two commands,
> > >and
> > >> >> making them optional based on the $(wildcard)? I'm still not clear
> > >what
> > >> >> the problem is.
> > >> >>
> > >> >> Anyway, if this is an issue, then compal/paz00 and
> > >compulabl/trimslice
> > >> >> will need to be fixed for the SPL changes in the same way.
> > >> > 
> > >> > The problem is this:
> > >> > 
> > >> >>>>  ifneq ($(OBJTREE),$(SRCTREE))
> > >> > 
> > >> > is true, but these directories:
> > >> > 
> > >> >>>> +$(shell mkdir -p $(obj)../common $(obj)../../nvidia/common)
> > >> > 
> > >> > don't exist because $(obj) is not under $(OBJTREE) in the SPL
> > >build,
> > >> > it's under $(SPLTREE)
> > >> 
> > >> OK, so I think the issue is just that $(obj) isn't the correct place
> > >to
> > >> mkdir these, not that we shouldn't attempt to mkdir any directory. In
> > >> other words, don't you need to switch between mkdir in the object
> > >tree
> > >> or the SPL tree rather than switching between doing a mkdir and not?
> > >> It's quite possible this only affects builds where OBJDIR!=SRCDIR, so
> > >a
> > >> regular build might not show up the problem I /think/ exists in the
> > >code
> > >> quoted a couple of emails above.
> > >
> > >$(obj) is always the place where the object files are going to be
> > >placed, that may be in $(OBJTREE) or in $(SRCTREE) or in $(SPLTREE)
> > >depending on what you're building and what you have set.
> > >
> > >I think the $(wildcard) suggestion I made is the most straightforward,
> > >it basically says "we're about to spit out an object file to here, so
> > >make sure the directory exists first".  In the "normal" case where
> > >your object files are in your source tree the directory will already
> > >exist so it won't do anything.
> > 
> > Ah right, I understand now.
> > 
> > But why not make it super-simple and just run the mkdir unconditionally;
> > it won't cause any harm for an in-tree object location, but removes the
> > need for anyone to think about the conditional logic.
> 
> Shouldn't this really be handled by the commands that create files in those
> directories? They could check that the directories exist, and create them if
> necessary, before executing their actual commands.

The normal rules make sure that $(obj) exists, it's only because
these boards generate object files in $(obj)../common and
$(obj)../../nvidia/common that there's a problem and we need to do
something special.

Stephen's idea of just the unconditional mkdir makes the most sense,
we don't really save anything by skipping it if the directory already
exists. 

-Allen
-- 
nvpublic