[U-Boot] Problem converting da850evm to generic board and use libfdt

[Simon Glass]

Hi Peter,

On 3 December 2014 at 13:53, Peter Howard <pjh at northern-ridge.com.au> wrote:
> On Wed, 2014-12-03 at 06:38 -0700, Simon Glass wrote:
>> Hi Peter,
>>
>> On 2 December 2014 at 14:59, Peter Howard <pjh at northern-ridge.com.au> wrote:
>> >
>> > I'm trying to make two changes to building u-boot for the da850evm.
>> >       * Use the generic board code to get rid of the warning, and
>> >       * Enable libfdt to allow booting of linux with a standalone dtb
>> >         image.
>> >
>> > The first part appears to be simple.  Just adding
>> >
>> >         #define CONFIG_SYS_GENERIC_BOARD
>> >
>> > in include/configs/da850evm.h works with no obvious side-effects.
>> >
>> > However, adding
>> >
>> >         #define CONFIG_OF_LIBFDT
>> >
>> > is a different story.  It appears to introduce memory corruption when
>> > loading the environment.  On first boot it gives the "bad CRC!" warning
>> > and uses the default environment.  If you *don't* save the environment
>> > you can boot fine (including manual editing of the environment). However
>> > if you save the environment via saveenv bad things happen on the next
>> > boot.  An example log:
>> >
>> > U-Boot SPL 2015.01-rc1 (Nov 27 2014 - 14:30:26)
>> >
>> >
>> > U-Boot 2015.01-rc1 (Nov 27 2014 - 14:30:26)
>> >
>> > I2C:   ready
>> > DRAM:  64 MiB
>> > WARNING: Caches not enabled
>> > MMC:   davinci: 0
>> > SF: Detected M25P64 with page size 256 Bytes, erase size 64 KiB, total 8 MiB
>> > In:    serial
>> > Out:   serial
>> > Err:   serial
>> > SF: Detected M25P64 with page size 256 Bytes, erase size 64 KiB, total 8 MiB
>> > Warning: Invalid MAC address read from SPI flash
>> > Net:   DaVinci-EMAC
>> > Error: DaVinci-EMAC address not set.
>> >
>> > U-Boot > help
>> > data abort
>> > pc : [<c108ffd8>]          lr : [<c10900b4>]
>> > sp : c3e5f838  ip : 00000000     fp : c3e5fda4
>> > r10: c10b1f28  r9 : c3e5ff08     r8 : 0000000e
>> > r7 : c10b22c4  r6 : c10aa2a0     r5 : 00000000  r4 : 0000001b
>> > r3 : c10b8f70  r2 : 00000001     r1 : c3e5f840  r0 : ffffffff
>> > Flags: Nzcv  IRQs off  FIQs off  Mode SVC_32
>> > Resetting CPU ...
>> >
>> > If I rebuild  with CONFIG_OF_LIBFDT removed again from da850evm.h the
>> > problem disappears.  And you can see that the saveenv worked (i.e. the
>> > environment is what was saved before the reboot and data abort).
>> >
>> > I've traced the problem as far as the inline version of console_puts()
>> > in common/console.c.  The table dispatch there and the fact that the
>> > problem appears only when you load the environment makes me think it's
>> > memory corruption.
>> >
>> > Note: if you do *not* specify CONFIG_SYS_GENERIC_BOARD you still get the
>> > data abort, however it takes a bit more effort to trigger (like actually
>> > looking at the environment :-)  )
>> >
>> > (Note: This is building against the u-boot-2015.01-rc1 tree)
>> >
>> > Suggestions?
>>
>> In case it helps, I got the same symptom (help crashes) and it was due
>> to BSS not being cleared. Stefan (on cc) found this problem - he said
>> something to do with GDT calculation or handling. However it is just a
>> guess and probably has nothing to do with your issue.
>
> I may be missing something, but the GDT appears to be x86-specific
> whereas I'm building for ARMv5.

OK for some reason I thought this was PPC!

Maybe you can find your pc in System.map and work out where it is
going wrong? Are you hitting some image size limit?

pc : [<c108ffd8>]

Regards,
Simon