Kevin,
As we discussed at ELC, it would be nice to test ARM big endian in the board farm. Here are some instructions on how to get this running:
1 Take the Buildroot branch at http://git.free-electrons.com/users/thomas-petazzoni/buildroot/log/?h=for-ke.... It is Buildroot 2014.02 + one patch for the AArch64 symlink + one patch for the ARM big endian Linaro toolchain.
2 Build a Buildroot configuration such as:
BR2_armeb=y BR2_cortex_a8=y BR2_ARM_EABIHF=y BR2_TOOLCHAIN_EXTERNAL=y BR2_TARGET_ROOTFS_CPIO=y # BR2_TARGET_ROOTFS_TAR is not set
3 Build mvebu_v7_defconfig or multi_v7_defconfig with CONFIG_CPU_BIG_ENDIAN=y (no other change is needed, except your own configuration stuff maybe, like initrd support, devtmpfs and so on).
4 Boot
I've tested this right now on Armada XP OpenBlocks AX3-4. It is worth noting that in BE mode, the ATAGS are not used, so if your OpenBlocks has only 1 GB of RAM, the boot will crash (with some weird tty related panic). That's because the Device Tree for the OpenBlocks AX3-4 encodes a memory size of 3 GB, which some OpenBlocks have. If you fall into this issue, then change the memory node in the DT to use 1 GB only.
Normally, this should also work on Armada 370 Mirabox, though I haven't tested right now.
Do you think you could add this big endian test to the board farm?
In addition to this, it would be interesting if you could also test LPAE on Armada XP OpenBlocks AX3-4 (it should work on little endian, however I have never tested LPAE/big-endian).
Thanks a lot!
Thomas