Intel's "redundant prefix issue"

Posted Nov 16, 2023 9:43 UTC (Thu) by Sesse (subscriber, #53779)
In reply to: Intel's "redundant prefix issue" by mfuzzey
Parent article: Intel's "redundant prefix issue"

There are (old) AMD CPUs with non-encrypted and non-signed microcode. Some researchers have even managed to make small changes to them. Knock yourself out.

Intel's "redundant prefix issue"

Posted Nov 16, 2023 13:25 UTC (Thu) by geert (subscriber, #98403) [Link] (4 responses)

So we can convert these AMD CPUs to e.g. RISC-V or m68k CPUs? ;-)

Intel's "redundant prefix issue"

Posted Nov 17, 2023 0:13 UTC (Fri) by p2mate (guest, #51563) [Link] (2 responses)

Can we then finally have a 64bit version of the m68k architecture? :)

Intel's "redundant prefix issue"

Posted Nov 17, 2023 8:03 UTC (Fri) by geert (subscriber, #98403) [Link]

Apparently the Apollo Core 68080 does have 64-bit (quad-word) support.
Unfortunately it's proprietary.
http://www.apollo-core.com/index.htm?page=coding&tl=1

Intel's "redundant prefix issue"

Posted Nov 17, 2023 8:17 UTC (Fri) by Sesse (subscriber, #53779) [Link]

I don't really know what people think the microcode is capable of doing, but it's not like the CPU decoder is purely software, just in a funny language.

Intel's "redundant prefix issue"

Posted Nov 27, 2023 14:16 UTC (Mon) by immibis (subscriber, #105511) [Link]

No. 99% of the CPU is hard-wired, and the microcode file controls some of the more obscure features, edge cases and rarely executed or very complex instructions.