Gigabyte 990FXA-UD3 rev 4.0 installer issue

[vedalken254]

So I'm trying to install Gentoo (currently switching back to it after the old hard drive died and never bothered to reinstall) and I know the kernel needs iommu=soft for my network and USB2.0 ports to work. Thing is the darn minimal CD (written via Rufus 2.2 in Windows to a USB drive) won't accept iommu=soft. Should I actually NEED to get the liveDVD?

EDIT: Also, old Gentoo install was on my previous motherboard anyways.
2nd EDIT: If I use the LiveDVD, would I still need the Stage3 tarball?

[Keruskerfuerst]

You should use the Systemrescuecd here: http://www.sysresccd.org/Download