[U-Boot] u-boot 2018.07/2018.09 'data abort' kernel start failure with GCC 8.2.0 on sun8i (H3)

[Heinrich Schuchardt]

On 08/22/2018 01:05 AM, Auston Stewart wrote:
> Greetings,
> 
>   As others have reported
> (https://lists.denx.de/pipermail/u-boot/2018-July/334126.html), a 'data
> abort' occurs when attempting to load the kernel with recent u-boot
> compiled with recent GCC on Allwinner (Sunxi) H3 boards. I ran into this
> issue when performing a bootstrap of Shedbuilt GNU/Linux with upstream
> GCC 8.20, glibc 2.28 and binutils 2.31.1 on a Nano Pi Neo 512M board.
>   I brought up this issue in IRC and did some debugging with xypron, who
> asked that I message the list.
> 
> Configurations I've personally tested:
> u-boot 2018.07 nanopi_neo_defconfig / GCC 8.2.0 + Kernel 4.17.14 / GCC
> 8.2.0 = broken
> u-boot 2018.09-rc2 nanopi_neo_defconfig / GCC 8.2.0 + Kernel 4.17.14 /
> GCC 8.2.0 = broken
> u-boot 2018.05 nanopi_neo_defconfig / GCC 7.3.0 + Kernel 4.17.14 / GCC
> 8.2.0 = works
> u-boot 2018.03 nanopi_neo_defconfig / GCC 7.2.0 + Kernel 4.17.14 / GCC
> 8.2.0 = works
> u-boot 2018.09-rc2 ARMv7 unaligned access patch
> (https://lists.denx.de/pipermail/u-boot/2018-March/324202.html) /
> nanopi_neo_defconfig / GCC 8.2.0 + Kernel 4.17.14 / GCC 8.2.0 = broken
> 
> Error (captured on Nano Pi Neo 512M with 2018.09-rc2):
> (for complete log,
> see https://gist.github.com/austons/222c6f1fd304d0832bec9964a4f569f0)
> Starting kernel ...
> 
> data abort
> pc : [<5ff9f16c>]          lr : [<5ff76ed7>]
> reloc pc : [<4a02916c>]    lr : [<4a000ed7>]
> sp : 5bf50588  ip : 5bf568da     fp : 40008000
> r10: 5bf50698  r9 : 5bf55ee0     r8 : 00000400
> r7 : 00000000  r6 : 40008000     r5 : 49ff8000  r4 : 00000000
> r3 : 49ff8000  r2 : 49ff8000     r1 : 00000000  r0 : 00000000
> Flags: nZCv  IRQs off  FIQs off  Mode UK6_32
> Code: e12fff1e e52de008 fa000001 e3a00000 (e49df008)
> Resetting CPU ...
> 
>   I have access to a number of H3/sun8i test devices to assist in
> diagnosis. There is some speculation in the earlier thread that USB
> changes post-2018.07rc1 could be a cause, but the only confirmed
> workaround is reverting to earlier GCC.
>   Thank you for your time. Please let me know if there are other details
> I can provide.
> 
> Auston Stewart
> Shedbuilt GNU/Linux
> http://shedbuilt.net

Hi Auston,

I built Bananapi_defconfig with gcc 8.2 (Debian Buster) and had not
problem to boot Linux.

Best regards

Heinrich