Barebox build issue with `arm-cortex_a8-linux-gnueabihf` cross compiler

[robamu]

Hello,

Thanks for writing this amazing book.

I have a improvement suggestion for the chapter where the arm-cortex_a8-linux-gnueabihf cross compiler is built. (if this was not already added in the third edition)

I was able to use the cross-compiler when built as specified in the book until trying to build barebox. Here, I got weird compilation errors with the toolchain: selected processor does not support rev ... , see this issue: https://www.spinics.net/lists/u-boot-v2/msg37608.html .
The solution was to specify the FPU type as neon-vfpv3 as specified in this post: https://stackoverflow.com/questions/50284222/u-boot-for-beaglebone-black-wont-build-target-cpu-does-not-support-thumb-inst when building the toolchain. I think it might be a good idea to add that step on page 75

After that, I was able to build Barebox without issues. I also submitted an Errata for this.

Kind Regards
Robin