On Aug 4, 2008, at 3:19 PM, Jerry Van Baren wrote: > Kumar Gala wrote: >> On Aug 4, 2008, at 1:56 PM, Wolfgang Denk wrote: >>> In message <Pine.LNX. >>> [EMAIL PROTECTED]> you wrote: >>>> Added the 'fdtcmd' environment variable as a way to provide >>>> 'fdt' commands >>>> that the user can supply to manipulate the device tree after >>>> ft_board_setup() >>>> and before the tree is handled to the kernel. >>> Where exactly is the needed, i. e. which spoecific situation do >>> you >>> have in mind where this function cannot be implemented as part >>> of >>> either a "preboot" or a standard "bootcmd" command sequence? >> The situation is if we are fixing up or adding properties or nodes >> via the ft_board_setup() how do I go about modifying that before >> the device tree is handed to the kernel. >> An example would be if we start adding the i2c node via code in u- >> boot and after we have done that we want to add a frequency >> property at runtime w/o changing the u-boot code. >> - k > > My original way long ago initial cut didn't do the board and /chosen > fixups as part of the bootm execution. My original intent was that > we would run "fdt chosen" and "fdt bd" and whatever else was > necessary before running "bootm", including addressing Kumar's need. > > Unfortunately, it would have also broken backwards compatibility and > so the concept was sacrificed for backwards compatibility. :-/ > > Is there a better way of doing this... perhaps have a flag that says > if "fdt chosen" and/or "fdt bd" is run, don't re-run it as part of > bootm? Maybe have an env variable that suppressed the calling of > "fdt chosen" and "fdt bd" in bootm ("nofdtfixup"?)? Still ugly, but > it would maintain backwards compatibility but also allow us finer > grained control of when "fdt chosen" and "fdt bd" (add "fdt cpu"?) > is run and allow our users to wedge additional fdt stuff in the boot > sequence.
Is that really any better than having the ability to "execute" an environment variable that has 'fdt' commands in it as part of bootm? - k ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ U-Boot-Users mailing list U-Boot-Users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/u-boot-users