On 02/09/2016 10:58 PM, Masahiro Yamada wrote:
2016-02-10 3:18 GMT+09:00 Tom Rini <tr...@konsulko.com>:
On Tue, Feb 09, 2016 at 10:53:48AM -0700, Stephen Warren wrote:
On 02/09/2016 10:43 AM, Tom Rini wrote:
On Tue, Feb 09, 2016 at 10:26:14AM -0700, Stephen Warren wrote:
On 02/09/2016 10:01 AM, Tom Rini wrote:
On Tue, Feb 09, 2016 at 08:11:15AM -0800, James Chargin wrote:
On 02/08/2016 05:32 PM, Stephen Warren wrote:
From: Stephen Warren <swar...@nvidia.com>
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes,
all files get rebuilt. In a continuous integration environment, the value
will change every build. This wastes time assuming that incremental
builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_FLAGS and add it to the end of
"local version".
This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is
printed at boot.
Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas
New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)
I would urge this not be done. The display of the BUILD_TAG on
startup is pretty useful in my environment. It's been there for a
long time and some of my users have grown used to it.
Of all the parts of the sign-on message, I'd rather the git hash go
away than the BUILD_TAG. None of my users really care about the
level of detail of the git hash and won't spend the time required to
use this hash to determine if they have the version they want. (Some
don't have a repo clone, and don't care to, and so can't easily make
the correspondence even if they wanted to).
Yeah, I think this is too widely used of a thing to change. FWIW, I
really like githashes since it means you can see if $random-binary is
something you have in $vendor-tree or not. So I think in this case, NAK
on the patch and maybe need to poke Travis-CI on how to or not to tag
things?
Do you mean you think people currently rely upon the ", Build: xxx"
format in the sign-on message, and the "version" command /not/
printing that information?
I mean that the places we construct strings like this are likely relied
upon by people, yes.
If so, I'll go back to trying to work out how to get Kbuild to
transfer the environment variable into a CONFIG_XXX option so that
modifying it only causes a rebuild of the one file that uses the
value.
A quick peak and I think that:
(a) LOCALVERSION needs a little love somewhere to ensure that it in fact
does not exceed 64 characters (and pushing upstream to the kernel
anything relevant here)
(b) Yes, adjusting BUILD_TAG into CONFIG_BUILD_TAG is probably the best
answer and probably not even that bad. I don't think we need an
automagic conversion, just noting it in the release emails and the
sudden lack of Build: should get people that are using it to update
their scripts.
Unfortunately, simply renaming the variable won't work;
Kconfig/Kbuild need to know something about it in order to do their
rebuild-only-on-change magic (and the value must be removed from
CFLAGS too). I was having a hard time getting that to work, but I'll
take another look.
Right. Can't we just make it another string Kconfig like LOCALVERSION,
not need to pass -D.... and then it's set via poking the config file by
CI, etc?
We are discussing two things together.
[1] avoid full build
[2] change of the version string format and build-flow
Nobody would complain about fixing [1] only.
(Feel free to continue discussion if you want [2].)
As Stephen pointed out, KBUILD_CFLAGS is passed to all the C files.
The environment "BUILD_TAG" is only referenced from lib/display_option.c,
so how about passing the flag to the file only?
Try the following patch:
diff --git a/lib/Makefile b/lib/Makefile
+CFLAGS_display_options.o := $(if $(BUILD_TAG),-DBUILD_TAG='"$(BUILD_TAG)"')
That's a nice simple idea, and should work well. I'll go validate it.
The only disadvantage is that if someone wants to start using BUILD_TAG
elsewhere, they'd have to manually add it to CFLAGS for that file too.
If we could import the environment variable into Kconfig automatically
somehow as CONFIG_BUILD_TAG, that would not be needed; using
CONFIG_BUILD_TAG would "just work". However, if you think we can live
with that, I'm all for it.
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
