RSB: add GRUB2 to the tools.

[Chris Johns]

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?

Chris