Since the last update that replaced the linux kernel in my 64-bit ubuntu v12.04 system, the computer has been reporting error messages early in the "maroon-brown screen" portion of the boot process.
Those messages are 8 identical lines that say:
microcode: failed to load file amd-ucode/microcode_amd_fam15h.bin
This makes sense, since my CPU is an 8-core AMD FX8150 "bulldozer", which I believe is family 0x15.
This started just after the common software update that happens at bootup time, but I can't be certain the two events are related. Nonetheless, this is certainly possible.
About the same time my system started freezing at seemingly random times, sometimes after hours of software development, sometimes only minutes after booting up. Again, I can't be certain this is related to the above, but I haven't made changes to my hardware since I upgraded my video card to nvidia GTX680 about two months ago.
What is this microcode that's being loaded, where does it come from, why does it fail, what kind of problems will or may be caused by the failure, and how do I get these files to install at bootup?