From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Date: Wed, 13 Apr 2016 11:00:07 -0600 Subject: [U-Boot] [PATCH] jetson-tk1: Set fdtfile environment variable In-Reply-To: <570E6B19.1090402@suse.de> References: <1460551699-30796-1-git-send-email-afaerber@suse.de> <570E41C0.1010904@suse.de> <570E665F.405@wwwdotorg.org> <570E6B19.1090402@suse.de> Message-ID: <570E7B17.9030701@wwwdotorg.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 F?rber wrote: >>> Am 13.04.2016 um 14:48 schrieb Andreas F?rber: >>>> 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 >>>> Cc: Alexander Graf >>>> Signed-off-by: Andreas F?rber >>>> --- >>>> 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.