On 04/13/2016 11:42 AM, Andreas Färber wrote:
Am 13.04.2016 um 19:00 schrieb Stephen Warren:
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 <swar...@nvidia.com>
Cc: Alexander Graf <ag...@suse.de>
Signed-off-by: Andreas Färber <afaer...@suse.de>
---
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
You're late for that discussion, we had that months ago on this mailing
list. We already concluded that SUSE does not and will not generate
extlinux.conf; EFI is a boot mechanism that we already support from x86
and aarch64 and that there are tools for (e.g., grub-mkconfig), unlike
extlinux.conf. There was also a FOSDEM talk on extlinux.conf that can be
summarized as some people like it and there's nothing wrong with it but
it's not a one-size-fits-all solution for everyone, including non-Linux
OSes such as Haiku.
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.
$fdtfile needs to be the Linux filename. It does not always follow the
same pattern as the U-Boot variables you suggest here.
CONFIG_DEFAULT_DEVICE_TREE ".dtb" might work better, and that was my
question to you.
That pattern is a good default that at least historically applied to all
the systems where the distro bootcmds were enabled. Perhaps the set of
systems using the distro bootcmds has increased now so the default isn't
always applicable. Boards can set $fdtfile /if/ needed because of that,
but I don't think should be forced to in all cases where the default
makes sense.
It's part of the generic mechanism, so not just select boards. Yet I was
told that all boards are expected to set their cacheline size (although
that is not a board but CPU property), so similarly we can (yes, newly)
desire all boards to provide DT related settings as well.
OK, but enabling the feature on boards where we know the requirements
aren't met doesn't seem useful, since it won't work well, as evidenced
by this patch.
If you would supply a feature-complete DT in the first place, we
wouldn't need $fdtfile here, but it seemed that that was not realistic
to expect for the upcoming U-Boot release.
Given the current primary DT source location, I don't think the issue is
complete-vs-incomplete DTs at all. However, that's straying quite off-topic.
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