On Wed, Feb 21, 2018 at 09:54:41AM -0500, Tom Rini wrote: > On Wed, Feb 21, 2018 at 03:38:42PM +0100, Simon Goldschmidt wrote: > > On 21.02.2018 14:35, Tom Rini wrote: > > >On Tue, Feb 20, 2018 at 10:59:33AM +0100, Lukasz Majewski wrote: > > >>On Tue, 20 Feb 2018 09:00:56 +0100 > > >>Maxime Ripard <maxime.rip...@bootlin.com> wrote: > > >> > > >>>On Mon, Feb 19, 2018 at 07:47:52PM +0200, Sam Protsenko wrote: > > >>>>On 18 February 2018 at 23:22, Wolfgang Denk <w...@denx.de> wrote: > > >>>>>Dear Sam, > > >>>>> > > >>>>>In message > > >>>>><CAKaJLVsWKpGeEuS=iZ7QCtZrDfUSA=8gzo3zjdr-vgw-muc...@mail.gmail.com> > > >>>>>you wrote: > > >>>>>>Right now U-Boot and SPL logs are cluttered with bogus warnings > > >>>>>>like these (on X15 board, but I'm pretty sure it should appear > > >>>>>>on many others): > > >>>>>> > > >>>>>> Loading Environment from FAT... > > >>>>>> *** Warning - bad CRC, using default environment > > >>>>>I donpt want to question the purpose of your patch series in > > >>>>>genral, but: > > >>>>Oh, it's merely a discussion, not a patch series. I probably > > >>>>shouldn't have been added that RFC tag, it's confusing, sorry. > > >>>>>This is NOT a bogus warning - actually it is something which is > > >>>>>not supposed to happen on any sane system. If it does on your > > >>>>>board even after first boot and running "env save" at least once, > > >>>>>then you have some problem either in the design or implementation > > >>>>>of your board code. > > >>>>> > > >>>>>So this is a very valid warning which means: FIX ME! > > >>>>AFAIU, that behavior was changed in the mentioned patch (please see > > >>>>my original message). Let me elaborate a bit. In v2018.01 everything > > >>>>works fine and none errors/warnings are present on my boards (AM57x > > >>>>EVM and X15 board). The problem appears after commit fb69464eae1e > > >>>>("env: Allow to build multiple environments in Kconfig"). Now U-Boot > > >>>>tries to load the environment from SD card first (uEnv.txt file on > > >>>>FAT partition), and then from eMMC partition. In case when SD card > > >>>>is not inserted, I observe mentioned errors. So I'm not sure how to > > >>>>handle this properly, that's why I created this thread... Let me > > >>>>try and explain my concerns better: > > >>>> 1. On the one hand, it's good to check the environment on both SD > > >>>>card and eMMC (that was done in mentioned patch). This case seems to > > >>>>be legit (at least as far as I understand it), i.e. when SD card is > > >>>>not inserted, it's fine, we just check the env on eMMC > > >>>> 2. But on the other hand, errors shouldn't appear in boot log, if > > >>>>it's legit case, it's confusing the user > > >>>That patch intent was to keep the current behaviour as is for all > > >>>users, so the fact that you now have the FAT environment enabled is an > > >>>unwanted side-effect. > > >>The same situation is on Beagle Bone Black. Even though with OE it is > > >>built to use eMMC for storing its envs, by default it also has envs in > > >>FAT support enabled. > > >> > > >>For that reason, u-boot on this board looks for envs in FAT first and > > >>similar message is printed. > > >> > > >>IMHO, we now have (unintentionally) the situation where implicitly > > >>reading envs from FAT has the highest priority. > > >It's not so much unintentional but rather that the mechanism to define > > >the priority order isn't being provided specifically by > > >board/ti/am335x/board.c so we get the default order. > > > > > >And one thing that I think does need to happen now is that the error > > >messages about "didn't find valid environment in ..." need to be > > >rethought a bit. It would probably also make sense to move from every > > >env operation tries every possible env location to env init finds the > > >first valid location, tells the user clearly it's using that, and then > > >always uses it. > > > > But it's like that already, isnt' it? Env load selects the first valid > > location in the list and env save uses that location. All other env > > operations work on the environment in memory. > > For saveenv we have: > for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) { > ...
In the default case, env_driver_lookup will return the location where the environment with the highest priority has been loaded. > > Also, for transitioning e.g. from MMC to FAT, we would need a mechanism to > > store to an environment place other than the one selected at load time. > > Ah, so we have different valid use cases. Maybe a new env sub-command, > switch? We implemented it by overwriting the priority look up. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
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