P2 Silicon Doc - now without the headache!
Wuerfel_21
Posts: 5,568
I ported Chip's P2 Silicon google doc (you know the one) to my Markdown-based website format.
Check it out: https://p2docs.github.io/mirror/p2silicon.html
There may still be some errors, please point them out if you see them.
This has many potential advantages over the original google docs version:
- Loads quickly and doesn't cause your fans to rev up
- No risk of accidentally editing it
- No 3rd party vandalism inserted from aforementioned accidents and assorted stupidity
- Resistant to any theoretical attempts at 1st party vandalism (the Reimu plush will keep it safe and sound, she is a good steward)
- Resistant to Google-related enshittification (but still hosted on GitHub, so exposed to Microsoft)
Potential downsides:
- TOC doesn't go into the sidebar (because p2docs' layout wasn't designed for huge monolith pages)
- Process for updating it is a bit more difficult (but AFAIK this particular doc has been stale for a while)
Also note that while this page has the HyperJump script on it, it will only lead you to the regular unoffical p2docs pages, whose coverage differs from the official docs.
Comments
Nice. Think you added this part, right? The "usually"?
It is usually not possible to execute code from hub addresses $00000 through $003FF, as the cog will instead read instructions from the cog register or lookup RAM as indicated above.Kind of like the idea of having secret code that takes a trick to execute...
Guess this can't work in Spin2 mode right? Has to be pure assembly program?
Yes, that's an edit I suggested, so I kept it.
That space is just taken up by the Spin2 interpreter when it's in use, so it's not that useful. It's a nice secret feature though.
Hmm... Maybe a way to restart the Spin2 interpreter then?
You can do that already.
You can't run any normal code in low memory hubexec because branches don't work.
Hmm… Maybe a way to start alternative interpreter then?
That doesn't wouldn't require the wraparound glitch to begin with.
This is not the place to discuss this, either.
One thing that maybe could use fixing in both is the memory space?
Seeing this a lot:
$00400..$FFFFF hub RAM
But, hub ram only goes to $7FFFF
Seems the docs are still imagining a universe where there'll be a new P2 with more ram?
Seems unnecessarily confusing to me...
Read the doc again if you think that :P
It just so happens that the 512K real chip we have has memory gaps, but the full 20-bit address space still exists.
Anyways, the point is not to editorialize the doc, that's what the main pages are for.