RSB: add GRUB2 to the tools.

[Karel Gardas]

On 11/10/21 11:04 PM, Chris Johns wrote:
> On 11/11/21 5:32 am, Karel Gardas wrote:
>> the attach patch adds GRUB2 into the RSB RTEMS tools. Idea is to use
>> that on amd64 BSP for building bootable images. That's also the reason
>> why it is used only on 6/rtems-x86_64 bset only.
> 
> Thank you for adding this and posting it here.
> 
> Does grub build on all supported hosts, ie Windows, MacOS, FreeBSD and Linux?

Wow! I've tested only build on Ubuntu 20.04. I'll see what I can do
about others. FreeBSD (13) is most easy to do here actually.

Thanks,
Karel