Allow xell-gggggg to boot from XellLaunch on an RGH

[mitchellwaite]

The reason xell-gggggg hangs on a black screen when you try to start it from a running system with something like XeLLLaunch is because it's programmed to always go down the SoC init codepath, which is only appropriate when we're jumping to XeLL early on in the boot process. When starting from the dashboard (or on a JTAG) we should be going down the thread catch codepath.

To determine whether or not to go down the thread catch codepath, this PR checks to see if thread 0 has been started. Otherwise, we go down the SoC init path. I've tested this on my RGH falcon, 0f Xenon, rgh corona, and winch and it seems to work OK, but wider testing would be useful

This is based on my code pasted in the discord channel:

https://discord.com/channels/1415992251707818046/1415993110734962719/1432909307602534522

[mitchellwaite]

Nvm, going to close this one. Doesn't appear to work on my RGH3 corona... will need to come back to this eventually.

[InvoxiPlayGames]

From startup threads code:std(irq_cntrl + 0x2070, 0x7c);

You're checking: if(0x7C == ld((void*)irq_cntrl + 2070)) (no hex)

Could be a typo and just luck that it worked on another system..?

[mitchellwaite]

From startup threads code:std(irq_cntrl + 0x2070, 0x7c);

You're checking: if(0x7C == ld((void*)irq_cntrl + 2070)) (no hex)

Could be a typo and just luck that it worked on another system..?

Good catch, it's pretty late for me and I didn't notice the typo when I copied the code out of my own XeLL fork.

I'll fix it and retry in the morning. Fingers crossed that's it.

[mitchellwaite]

Corrected the typo, can confirm it now works on my corona 4gb and 16mb winch

[Swizzy]

Do you have a JTAG console to verify that it's working correctly there aswell still?

[mitchellwaite]

Do you have a JTAG console to verify that it's working correctly there aswell still?

I do have a JTAG falcon as well, I will test it there this evening and report back.

[mitchellwaite]

@Swizzy just tested on my falcon JTAG, everything works as expected. I'm able to boot from eject at system startup, from the dashboard with XellLaunch, and i can return to XeLL from another libxenon app.

I did force push back to commit f3f2d27, even though wakeup_cpus isn't really used anymore it is referenced by start_from_libxenon in startup.S. I can address that in a future change, or now if you'd like

[Swizzy]

@Swizzy just tested on my falcon JTAG, everything works as expected. I'm able to boot from eject at system startup, from the dashboard with XellLaunch, and i can return to XeLL from another libxenon app.

I did force push back to commit f3f2d27, even though wakeup_cpus isn't really used anymore it is referenced by start_from_libxenon in startup.S. I can address that in a future change, or now if you'd like

I think we'll adress that at a later time.