[yocto] BBB doesn't boot

[Denys Dmytriyenko]

On Thu, Apr 17, 2014 at 04:25:51PM -0700, Khem Raj wrote:
> On Thu, Apr 17, 2014 at 2:31 PM, William Mills <wmills at ti.com> wrote:
> > On 04/17/2014 03:10 PM, Denys Dmytriyenko wrote:
> >>
> >> On Tue, Apr 15, 2014 at 05:07:10PM -0600, Gary Thomas wrote:
> >>>
> >>> On 2014-04-15 13:43, Denys Dmytriyenko wrote:
> >>>>
> >>>> On Tue, Apr 15, 2014 at 01:41:12PM -0400, Denys Dmytriyenko wrote:
> >>>>>>>>>
> >>>>>>>>> Some other things I tried with a "long" TMPDIR path (note that it's
> >>>>>>>>> the
> >>>>>>>>> TMPDIR path that makes the difference - in my tests I've been using
> >>>>>>>>> /home/paul/poky/build2/much/longer/path/to/tmp). None of this
> >>>>>>>>> helped:
> >>>>>>>>>
> >>>>>>>>> * kernel built with gcc 4.7.2 and binutils 2.23.2
> >>>>>>>>> * u-boot built with gcc 4.7.2 and binutils 2.23.2
> >>>>>>>>> * u-boot from
> >>>>>>>>> http://downloads.angstrom-distribution.org/demo/beaglebone/
> >>>>>>>>> * earlyprintk and CONFIG_DEBUG_LL - no additional output printed
> >>>>>>>>>
> >>>>>>>>> I think we're now at the point where we'd benefit from someone with
> >>>>>>>>> better
> >>>>>>>>> knowledge debugging the issue.
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> Ok, should we expand the search area? Since this is supposed to be
> >>>>>>>> vanilla
> >>>>>>>> 3.14 kernel, can we try other platforms and see if they are
> >>>>>>>> similarly
> >>>>>>>> affected? I'll try pinging our kernel guys for any ideas...
> >>>>>>>
> >>>>>>>
> >>>>>>> As far as I know it has only been observed with beaglebone (both
> >>>>>>> white and
> >>>>>>> black, if it makes a difference). FWIW, qemuarm images from the
> >>>>>>> autobuilder
> >>>>>>> boot just fine, and apparently the same is true of edgerouter
> >>>>>>> (different
> >>>>>>> architecture but also uses u-boot).
> >>>>>>
> >>>>>>
> >>>>>> But do those other platforms use uImage or zImage?
> >>>>
> >>>>
> >>>> I don't yet know what is going on, but building in the same directory
> >>>> with
> >>>> sources (B = S) makes it work regarless of the path length:
> >>>>
> >>>>
> >>>> /OE/RAM/poky-111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111/22222222222222222222222222222222222222222222222222222222222222222222/3333333333333333333333333333333333333333333333333333/tmp/work/beaglebone-poky-linux-gnueabi/linux-yocto/3.14+gitAUTOINC+928d7b2dda_0143c6ebb4-r0/linux
> >>>>
> >>>> So, I just commented out setting kernel-specific B in linux-yocto.inc
> >>>> and any
> >>>> kernel now boots with long path:
> >>>>
> >>>> #B = "${WORKDIR}/linux-${PACKAGE_ARCH}-${LINUX_KERNEL_TYPE}-build"
> >>>>
> >>>> I'm copying Richard and Bruce directly to see if they may have a quick
> >>>> insight
> >>>> and/or accept it as a workaround for the release. I'll keep digging
> >>>> further,
> >>>> but if anyone cares to verify the above workaround works for them, I
> >>>> would
> >>>> appreciate. Thanks!
> >>>>
> >>>
> >>> Verified - I rebuilt the kernel in a working tree with a longer
> >>> path (one in fact that had failed before) and it boots fine.
> >>>
> >>> Wonder what ${B} != ${S} is doing wacky...?
> >>
> >>
> >> Gary, et al,
> >>
> >> I've just submitted a patch to oe-core and yocto MLs that fixes this issue
> >> -
> >> could you please test it in your setup and confirm? Thanks!
> >>
> >
> > I updated Stefan's bug w/ more explanation.
> > I verified that Stefan's uImage-bad failed for me and then added the
> > following to uEnv.txt:
> > fdtaddr=0x88000000
> 
> hmmm so it seems kernel size grew enough to overwrite the area where
> uboot would put divice tree ?

Exactly! The overall kernel size was very close to the limit of previous space 
allocation in U-boot and enabling another feature or growing the build path a 
bit would overflow into and corrupt the device tree.


> has happened to me on ppc with kernel+initramfs where initramfs kept growing

I was told no other platforms were affected, including qemuarm! :) Yeah, I 
know, it can happen to anyone, even though by default it works fine...


> > uImage-bad (and uImage-good) worked w/ the above change to uEnv.txt.
> > Denys' patch fixes all the defaults in u-boot so that no uEnv.txt change is
> > needed.
> >
> > --
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