Hi Philipp, On 02/19/17 19:59, Dr. Philipp Tomsich wrote: > Igor, > >> On 19 Feb 2017, at 12:52, Igor Grinberg <grinb...@compulab.co.il> wrote: >> >> On 02/17/17 19:28, Philipp Tomsich wrote: >>> This introduces the ability to override the environment offets from the >>> device tree by setting the following nodes in '/config': >>> 'u-boot,mmc-env-offset' - overrides CONFIG_ENV_OFFSET >>> 'u-boot,mmc-env-offset-redundant' >>> - overrides CONFIG_ENV_OFFSET_REDUND >>> >>> To keep with the previous logic, the CONFIG_* defines still need to >>> be available and the statically defined values become the defaults, >>> when the corresponding properties are not set in the device-tree. >> >> That sounds too odd... >> DT's purpose is to describe the h/w... and that does not look so... >> We also, have a dt file name in the environment, so this creates will create >> a chicken and an egg problem… > > I don’t really follow… as far as I knew the DT name would have to come > from some other source anyway, as the device containing the env might > only be described through the device tree (e.g. mmc0).
Why? U-Boot can live pretty well w/o DT. > > U-Boot usually locates the FDT to use at a preconfigured address (or one > configured in the early environment). Or just by providing the address to bootz command... > This will not be the environment we’d > load from a MMC device configured via DM_MMC. > > So there shouldn’t be a chicken & egg here. > >> I really don't think we should go that direction. DT is not meant to provide >> a solution to all your problems... > > I don’t see how this is different from other entries in chosen and config as > of today: > common/autoboot.c allows an override through /config/bootdelay > common/board_r.c uses /config/load-environment > common/cli.c can pull in /config/bootcmd > drivers/serial/serial-uclass.c uses /chosen/stdout-path > > In fact, it is the absence of this mechanism that is causing problems today: > CONFIG_ENV_OFFSET is not configurable through Kconfig, so we would > need board-specific defines (e.g. CONFIG_SUNXI_BOARD_LYNX) and > matching #ifdef primitives in a shared header (sunxi-common.h in our case). Right. Exactly, I think we should move the CONFIG_ENV_OFFSET to Kconfig. And that will solve the problem. > > So putting this in the DT is the best (and least intrusive) option available. Ok. I see your point now. Yet I think we should keep the DT to its purpose - which is to describe the h/w (and not the s/w placement layout). -- Regards, Igor. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
