I have 2 AMD-based laptops, an less-recent HP G62 with an RV710 and a recent Aspire One 722 with a Radeon HD6290. The latter requires a recent fglrx driver, the former the legacy (12.4 or 12.6) version. Using the fglrx driver is especially important for the HP G62 as the free Radeon driver causes the graphics board to overheat, leading to a hardware shutdown of the computer.
Running Linux Mint Debian with a 3.10 kernel, I could install the required AMD Catalyst code on both machines, simply via the LMDE repositories (versions 13.4 and 12.6 "legacy"). The way things are set up, the kmods are compiled from source during the installation process, using dkms.
I then downloaded and built the Sabayon 3.12.6 kernel package, and managed to make the minimal change to the fglrx kmod code for it to build and install. This is really just a question to change a typedef.
By contrast, installing the AMD Catalyst 13.6 using equo on an otherwise uptodate Sabayon installation (on an external hdd) requires downgrading the kernel to 3.9 while this doesn't appear to be necessary given my experience described above.
Supposing I download the 13.6 installer from AMD in order to get the userland utilities, how would I go about installing the fglrx kmod, given Sabayon doesn't have the dkms utilities?