> The one thing which most leads me to believe this was an intentional backdoor? The S-boxes. If you look at that HN discussion, you'll find a link to a Mastod

> The one thing which most leads me to believe this was an intentional backdoor? The S-boxes. If you look at that HN discussion, you'll find a link to a Mastodon post from an Asahi Linux developer explaining that these "S-boxes" are actually an ECC calculation, and that the registers are probably cache debug registers, which allow writing directly to the cache bypassing the normal hardware ECC calculation, so you have to do the ECC calculation yourself if you don't want a hardware exception caused by an ECC mismatch on read (of course, when testing the cache, sometimes you do want to cause an ECC mismatch, to test the exception handling).