Upgrade SRC built i386 8.4 to 10.1 questions

[Todor Todorov]

Hi all,
I have doubts after reading info in the internet. Case is as following -
starting point source built i386 8.4 FreeBSD needs to be upgraded to 10.1.

I've used livecd to see that it boots and supports the hardware in advance.

The questions are:

1. can I use freebsd-update to migrate to 10.1 i386
2. can I use freebsd-update to migrate to 10.1 amd64
3. can I use source buildkernel + buildworld to migrate i386 8.4 to
amd64 10.1

Thanks,
Todor