On Tue, Feb 14, 2023 at 12:59:34PM -0700, Simon Glass wrote: > Hi Tom, > > On Tue, 14 Feb 2023 at 10:38, Tom Rini <tr...@konsulko.com> wrote: > > > > On Tue, Feb 14, 2023 at 09:58:59AM -0700, Simon Glass wrote: > > > Hi Tom, > > > > > > On Tue, 14 Feb 2023 at 09:31, Tom Rini <tr...@konsulko.com> wrote: > > > > > > > > On Sun, Feb 12, 2023 at 04:16:04PM -0700, Simon Glass wrote: > > > > > > > > > At present kconfig writes out several files, including: > > > > > > > > > > auto.conf - CONFIG settings used by make > > > > > autoconf.h - header file used by C code > > > > > > > > > > This works well but is a bit ugly in places, for example requiring > > > > > the use > > > > > of a SPL_TPL_ macro in Makefiles to distinguish between options > > > > > intended > > > > > for SPL and U-Boot proper. > > > > > > > > > > Update the kconfig tool to also output separate files for each phase: > > > > > e.g. > > > > > auto_spl.conf and autoconf_spl.h > > > > > > > > > > These are similar to the existing files, but drop the SPL_ prefix so > > > > > that > > > > > SPL_TPL_ is not needed. It also allows the CONFIG_IS_ENABLED() macro > > > > > to be > > > > > simplified, in a later patch, eventually replacing it with > > > > > IS_ENABLED(). > > > > > > > > > > When CONFIG_FOO is used within SPL, it means that FOO is enabled in > > > > > that > > > > > SPL phase. For example if CONFIG_SPL_FOO is enabled in the Kconfig, > > > > > that > > > > > means that CONFIG_FOO will be enabled in the SPL phase. So the SPL > > > > > builds > > > > > can just use CONFIG_FOO to check it. There is no need to use > > > > > CONFIG_SPL_FOO or CONFIG_IS_ENABLED() anymore. > > > > > > > > > > This of course means that if there is a need to access a PPL symbol > > > > > from > > > > > an SPL build, there is no way to do it. To copy with that, we need a > > > > > CONFIG_PPL_FOO to be visibilty to all SPL builds. > > > > > > > > > > So this change also adds new PPL_ output for U-Boot proper (Primary > > > > > Program Loader). So every CONFIG_FOO that is enabled in PPL also has a > > > > > CONFIG_PPL_FOO > > > > > > > > > > This allows SPL to access the TEXT_BASE for U-Boot proper, for > > > > > example, so > > > > > it knows where to load it. There are about 30 places where this is > > > > > needed, > > > > > in addition to TEXT_BASE. The environment has the same problem, adding > > > > > another dozen or so caes in include/config_distro_bootcmd.h but it has > > > > > been decided to ignore that for now. > > > > > > > > > > The feature is controlled by an environment variable, since it seems > > > > > to be > > > > > bad form to add flags to the conf tool. > > > > > > > > > > Rebuild the autoconf files if the split config is not present. This > > > > > allows > > > > > building this commit as part of a chain, without generating build > > > > > errors. > > > > > > > > > > These changes may benefit from some reworking to send upstream, e.g. > > > > > to > > > > > use a struct for the 'arg' parameter. > > > > > > > > > > Signed-off-by: Simon Glass <s...@chromium.org> > > > > > > > > This patch, I think, is where my largest problem is. We go from being > > > > able to say "if CONFIG_SPL_FOO is undefined, it is false" to "we must > > > > define CONFIG_SPL_FOO to false". There's around 150 cases of this, with > > > > the series. Why can we not extend the PPL logic (which I'm not super > > > > happy with, but, I understand and I think an audit of everything > > > > not-TEXT_BASE should be fairly straight forward), to say that if > > > > CONFIG_FOO exists and CONFIG_SPL_FOO does not exist, say CONFIG_SPL_FOO > > > > is now false. > > > > > > Well it is all about choices. > > > > > > We don't have to add a CONFIG_SPL_xxx to tell Kconfig that the PPL > > > symbol controls all phases. We can use the conf_nospl file instead. > > > But then the entire description is not in Kconfig. Of course, we might > > > expect that some of those things in conf_nospl might end up needing to > > > be controlled in SPL, so perhaps that file would shrink? Not sure > > > about that, though. > > > > > > It isn't just SPL , BTW. We might have any xPL symbol defined. > > > > > > I suppose you are thinking of something like: > > > > > > #define CONFIG_IS_ENABLED(x) IS_ENABLED(CONFIG_ ## xpl_prefix ## x) || > > > ( IS_ENABLED(CONFIG_ ## x) && !IS_ENABLED(CONFIG_ SPL_ ## x) && > > > !IS_ENABLED(CONFIG_TPL_ ##x) ..) > > > > > > But how do we deal with Makefiles? We still end up with the SPL_TPL_ > > > stuff. > > > > I see it as a very useful feature that today if we don't set > > CONFIG_xPL_FOO, it evaluates to false, anywhere we need it to. In all of > > the prep work for split config, I think we've seen one case where we got > > things wrong (in that it lead to failure). Split config build is doing a > > whole bunch of things to then remove this feature. And the series > > intentionally ignores the Makefile design issue / feature of wrapping > > large chunks with a check for being/not-being in an xPL_BUILD phase. > > In another thread you suggested moving to separate defconfig files for > each phase (I think). Presumably that would operate the same way as > this series, in that you would not be able to handle the special case > you mention. So I see this series as the best of both worlds - a > unified Kconfig (and .config) but with separate auto.conf files for > each phase. Plus we can drop the SPL_TPL_ stuff.
What I keep thinking of is that we would end up with separate configs. So while yes, we might need CONFIG_PPL_TEXT_BASE, we would not need CONFIG_SPL_DM_GPIO for example, because fooboard_spl_defconfig would set CONFIG_SPL=y and CONFIG_DM_GPIO=y. I don't know how workable this ends up being as we have about 7k symbols for full U-Boot and about 450 for SPL. And I really don't see the problem with SPL_TPL_ stuff. > We can add things to conf_nospl and then the behaviour is as you want > it, isn't it? I'd also rather not have a file that's going to get conflicted on, even if all of the comments started with "#" and so we could pass it through sort. But yes, that's better than adding unselectable options. > For the Makefile xPL ifdefs, is it essential to do anything there? We > could remove them, using the same techniques in this series. I would > quite like to, but we don't have to, if you like them. My reason for > wanting to remove them is that we end up refactoring things to enable > features in xPL, instead of just adding an xPL option. My point with the xPL ifdefs is that a number of config_nospl/def_bool n options could be resolved the same way. To me, the problem isn't that we have lines like: obj-$(CONFIG_$(SPL_TPL_)FOO += foo.o as I've encouraged people to add them, in the case of the MULTIPLEXER case I'm pretty sure, rather than finding the existing block of: ifneq ($(CONFIG_SPL_BUILD)$(CONFIG_TPL_BUILD),y) ... endif for the cases where we need to have something not built in SPL/TPL. Removing those guards would lead to a big increase in config_nospl lines, I suspect. > Finally, with the series I have, it is quite easy to add a new phase > if we want to. > > > > > > Yes, adding PPL moves a step forward and reduces the audit to only > > > uses of PPL, instead of the whole Kconfig. > > > > > > This series does get us closer to separate configs (it is really easy > > > to see what is enabled in each build just by looking at the > > > auto_xpl.conf files) and I think those 150 exceptions are not a big > > > price to pay. > > > > > > Ultimately I am coming to the view that we should extend the Kconfig > > > language to support multiple build phases, using a 'phase' property. > > > Zephyr is going to need it too, fairly soon[1]. > > > > > > Regards, > > > Simon > > > > > > [1] https://github.com/zephyrproject-rtos/zephyr/issues/54534 > > > > Yes, if the Kconfig language moves in a new direction, it would be good > > to follow and use that. > > Well I am thinking of moving it there...but would need to start by > upstreaming the two patches in this series. Well, honestly, I suspect if you can work with upstreams on Kconfig the language supporting the concepts of phases, natively, my concerns will be addressed, one way or another. Because something like: config DM_GPIO bool "DM GPIO support" phases PPL SPL TPL config ODDBALL_THING # phases PPL is implied when it's only valid there bool "Do this one weird trick in PPL" Means that we can yes/no options like DM_GPIO for each phase, and get xPL_ODDBALL_THING=n for free is much cleaner. -- Tom
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