[dpdk-users] Cross compile for ARM64 fails due to librte_vhost and pmdinfogen issues

[Thomas Monjalon]

Hi,

2016-09-12 22:20, Michael Wildt:
> I'm attempting to cross compile DPDK on an x86 for an ARM64 target. This
> fails in the following areas, using latest dpdk as of 9/12. When compiling
> natively there are no issues.

Your analysis below seems good.
Interestingly, I do not see such error (don't know why).
Please could you share the commands you are using?

> - librte_vhost, fails with:
> 
> /projects/dpdk_latest/lib/librte_vhost/vhost_user/virtio-net-user.c:250:23:
> error: array subscript is above array bounds [-Werror=array-bounds]
>    rvq = dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_RXQ];
[...]
> - buildtools/pmdinfogen, fails with:
> 
> == Build buildtools/pmdinfogen
>   HOSTCC pmdinfogen.o
> /projects/dpdk_test_wget/dpdk-16.07/build/include/rte_byteorder.h:
> Assembler messages:
> /projects/dpdk_test_wget/dpdk-16.07/build/include/rte_byteorder.h:53:
> Error: no such instruction: `rev16 %bx,%bx'
[...]
>   - The issue is due to the rte_byteorder.h file which gets symlink'ed with
> the ARM version at the beginning of the build. The pmdinfogen is always
> compiled for x86 thus the asm is failing. I see two ways to address this.
> 
> - Have pmdinfogen always pickup the local OS rte_byteorder.h file, not the
> ARCH symlinked one.

Yes we should not use DPDK headers in pmdinfogen or have a host-include/.

> - Fix pmdinfogen such that it gets cross compiled correctly as the rest of
> the code. Did a quick attempt by setting the HOST_OS to 0, , but then it
> fails at the HOST_LD.

No it must be native because it is part of the build system.