Re-building u-boot fails

Following the instructions for re-building u-boot in 27.1 for TX2, I get the following errors:

jwatte@ub16:/usr/local/jetson/tx2-3.0/64_TX2/Linux_for_Tegra_tx2/sources/u-boot$ sudo make clean
jwatte@ub16:/usr/local/jetson/tx2-3.0/64_TX2/Linux_for_Tegra_tx2/sources/u-boot$ sudo make p2771-0000-500_defconfig
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
  HOSTCC  scripts/kconfig/zconf.tab.o
  HOSTLD  scripts/kconfig/conf
#
# configuration written to .config
#
jwatte@ub16:/usr/local/jetson/tx2-3.0/64_TX2/Linux_for_Tegra_tx2/sources/u-boot$ sudo make
scripts/kconfig/conf  --silentoldconfig Kconfig
  CHK     include/config.h
  GEN     include/autoconf.mk
cc1: warning: unknown register name: x18
  GEN     include/autoconf.mk.dep
cc1: warning: unknown register name: x18
  CHK     include/config/uboot.release
  CHK     include/generated/version_autogenerated.h
  CHK     include/generated/timestamp_autogenerated.h
  UPD     include/generated/timestamp_autogenerated.h
  CC      lib/asm-offsets.s
cc1: warning: unknown register name: x18
lib/asm-offsets.c:1:0: error: bad value (armv8-a) for -march= switch
 /*
 ^
Kbuild:43: recipe for target 'lib/asm-offsets.s' failed
make[1]: *** [lib/asm-offsets.s] Error 1
Makefile:1264: recipe for target 'prepare0' failed
make: *** [prepare0] Error 2

I have exported

export CROSS_COMPILE=/usr/bin/aarch64-linux-gnu-

Is there some other setup I need to do?

hello snarky,

may i know what’s your ubuntu environment version ?
is it possible to upgrade your progress with JetPack 3.1 ?

FYI, i am able to compile u-boot with my ubuntu 14.04/ r28.1 sources following the steps in the document.
thanks

I’m using Ubuntu 16.04, with Jetpack 3.0 installed.

Unfortunately, I’m using an Auvidea J90 carrier board, and they just released the 3.0 support, so I can’t upgrade to 3.1 until they catch up.

Which steps, in which document? The document I found just said “cd to uboot, make clean, make defconfig, and make” which is a very small set of steps (as you can see, those steps are what I did above.)
Is there a document with more in-depth documentation?

Hi snarky,

Could you download the source and try again?
http://developer.nvidia.com/embedded/dlc/l4t-sources-27-1

I can build u-boot success with r27.1 sources (u-boot_src.tbz2).