After cross testing with GNU/Linux, i've found out that my Intel 82577LC em(4) ethernet adapter won't do gigabit ethernet even when forced to with media options on #OpenBSD *head scratching*
And OpenBSD has these fixes but in a separate .c file. I tried to import the NetBSD's miidevs relevant entry and rebuilt miidevs.h to no avail.
I've to admit i'm punching above my weight here. But i've learnt many things in the process, like mii and mdio. Won't look at network cables the same way now ^__^