> Am 13.04.2016 um 19:31 schrieb Stephen Warren <[email protected]>: > >> On 04/13/2016 11:21 AM, Alexander Graf wrote: >> >> >>>> Am 13.04.2016 um 19:00 schrieb Stephen Warren <[email protected]>: >>>> >>>>> On 04/13/2016 09:51 AM, Alexander Graf wrote: >>>>>> On 04/13/2016 05:31 PM, Stephen Warren wrote: >>>>>>> On 04/13/2016 06:55 AM, Andreas Färber wrote: >>>>>>> Am 13.04.2016 um 14:48 schrieb Andreas Färber: >>>>>>> The 4.5.0 kernel cannot cope with U-Boot's internal device tree, and >>>>>>> the >>>>>>> distro boot commands are looking for $fdtfile, so provide it to avoid >>>>>>> having users supply a dumb boot.scr doing a setenv fdtfile ...; boot, >>>>>>> defeating the purpose of generic EFI boot. >>>>>>> >>>>>>> Cc: Stephen Warren <[email protected]> >>>>>>> Cc: Alexander Graf <[email protected]> >>>>>>> Signed-off-by: Andreas Färber <[email protected]> >>>>>>> --- >>>>>>> include/configs/jetson-tk1.h | 4 ++++ >>>>>>> 1 file changed, 4 insertions(+) >>>>>>> >>>>>>> diff --git a/include/configs/jetson-tk1.h >>>>>>> b/include/configs/jetson-tk1.h >>>>>>> index 59dbb20..82a4be4 100644 >>>>>>> --- a/include/configs/jetson-tk1.h >>>>>>> +++ b/include/configs/jetson-tk1.h >>>>>>> @@ -63,6 +63,10 @@ >>>>>>> /* General networking support */ >>>>>>> #define CONFIG_CMD_DHCP >>>>>>> >>>>>>> +#define BOARD_EXTRA_ENV_SETTINGS \ >>>>>>> + "fdtfile=tegra124-jetson-tk1.dtb\0" \ >>>>>>> + "" >>>>>> >>>>>> Is there any more intelligent solution than doing this for each board? >>>>> >>>>> Yes, the distro boot scripts shouldn't be using $fdtfile >>>>> unconditionally since it's not guaranteed to be set. The model is that >>>>> boot scripts determine the FDT filename, and $fdtfile is an optional >>>>> override. >>>> >>>> The point of all of the efi magic is that we can completely get rid of >>>> boot scripts. Boards use the distro scripts, everything else gets >>>> implicitly detected and executed. The way other boards deal with common >>>> code mapping into separate boards is to either implement a "findfdt" >>>> scriptlet or directly write the fdtfile variable (e.g. beaglebone) in >>>> board init (e.g. rpi). >>>> >>>>> It looks like the hard-coded use of $fdtfile was added into the EFI >>>>> path, which I didn't get to review, and which shouldn't be enabled by >>>>> default but unfortunately is. >>>> >>>> s/un// :) >>>> >>>> Just imagine a world where people don't have to worry about bootloaders >>>> anymore. Things would "just work". You plug in a usb stick, it comes up, >>>> boots Linux, everthing goes without anyone touching boot scripts, >>>> downloading board specific files, etc. You could get a random >>>> distribution from a common download page from somewhere and just run it. >>>> >>>> Well, you can also just look at any random x86 system. They get at least >>>> that part pretty right these days. >>> >>> Well, you can also get the same benefit using extlinux.conf, and without >>> relying on EFI:-P >>> >>> Anyway, nothing in your benefits-of-EFI statement implies that relying on >>> $fdtfile being set is correct. That's a new requirement that didn't exist >>> before. Either the requirement needs to be removed (e.g. using a default >>> FDT filename such as "${soc}-${board}${boardver}.dts") or only enabling >>> this functionality on boards that do set $fdtfile, since it relies on that. >> >> On boards that fon't set fdtfile we just don't load it, because we can't >> find the file. So you're getting a working grub2 payload, but Linux gets an >> empty device tree unless you pass it in using the grub2 "devicetree" command. >> >> It's really just a convenience helper. And a nice piece to the puzzle that >> by convention allows users to think less about u-boot internals. The efi >> code works fine without. > > Except for the fact that it doesn't just work, since if it did there wouldn't > be a need for the patch in this email thread. > > I think the correct fix is to abandon this patch, and have the EFI code (i.e. > the scripts in the distro boot commands most likely) calculate a default > value for $fdtfile if it isn't already set. Something like: > > if test -n "${fdtfile}"; then > set _fdt ${fdtfile}; > else > set _fdt ${soc}-${board}${boardver}.dtb; > > ... and use ${_fdt} instead of relying on ${fdtfile}. > > If you still want to pursue this patch, it should be enhanced to cover all > boards where the EFI code is enabled and $fdtfile isn't already set somehow, > which I expect is almost all U-Boot boards since the Kconfig option is > "default y".
Only the ones that do distro bootcmd. I'll send a patch later. I really like the idea :). Thanks! Alex _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
