Thanks for the links/info. I realise this machine still has closed source blobs in it anyway (including for things like SATA connections, and usb ports), but I’ve still tried to limit the number of binary blobs involved as much as possible (I’ve me_clean’ed it, for instance, and installed coreboot).
I wish there were clearer information about the details of necessity/function of the intel microcode, but I suppose that’s the whole (problematic) nature of closed source code…
edit: after installing the intel ucode, and reconfiguring dracut, it seems to turn out that intel hasn’t updated the microcode for my processor recently anyway…:
[ 0.000000] microcode: microcode updated early to revision 0x1c, date = 2015-02-26
[ 0.594751] microcode: sig=0x306a9, pf=0x10, revision=0x1c
[ 0.594852] microcode: Microcode Update Driver: v2.2.