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Worklog Some PS2 Project

Lightning

Lightning

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Tschicki said:
Not even the rubber membrane swiches @Lightning recommended were helping, they were too big and even using just the plain membrane didn't quite fit right.
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Ahh shoot! Well that's too bad, but as usual necessity is the mother of invention, and you seem to have come up with a pretty innovative solution!

Did you ever end up finding out the voltage for those JoyCon sticks?
 
uyjulian

uyjulian

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For ROM-less DVD player, it is basically the same situation as SCPH-10000. It is actually possible to install it on a memory card and boot from it; search exactly "PS2 DVD Player modifications".

I also plan to release a tool that can do in-system flash ROM programming based on what DTL-T10000 can do. Personally, for me, I think it would be better to have a similar setup as System 147/148 where there are two partitions; first one mapped at 0xBFC00000... for boot which chainloads the second one. And the second partition is the one is that should be flashed. That way if something goes wrong in flashing it would still be possible to boot from USB or memory card to recover (drivers for which are included in first partition).

Another idea I'm thinking of is to hook up (Q/O)SPI flash ROM to SSBUS and bitbang (Q/O)SPI for more storage without needing to solder more address/data lines.

Another idea would be to compress the contents of ROM under 256KiB and then hook up a RP2040 to use with e.g. PicoROM. (OSDSYS, PS2LOGO, PS1DRV, dvdplayer might need to be loaded from somewhere else)
 
Yayixbox

Yayixbox

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uyjulian said:
En el caso de los reproductores de DVD sin ROM, la situación es básicamente la misma que la del SCPH-10000. De hecho, es posible instalarlo en una tarjeta de memoria y arrancar desde ella; busque exactamente "modificaciones del reproductor de DVD de PS2".

También planeo lanzar una herramienta que pueda realizar programación de ROM flash en el sistema basada en lo que puede hacer DTL-T10000. Personalmente, para mí, creo que sería mejor tener una configuración similar a la del Sistema 147/148 donde hay dos particiones; la primera asignada a 0xBFC00000... para el arranque que carga en cadena la segunda. Y la segunda partición es la que se debe flashear. De esa manera, si algo sale mal durante el flasheo, aún sería posible arrancar desde USB o tarjeta de memoria para recuperar (los controladores para los cuales están incluidos en la primera partición).

Otra idea en la que estoy pensando es conectar la ROM flash (Q/O)SPI a SSBUS y bitbang (Q/O)SPI para obtener más almacenamiento sin necesidad de soldar más líneas de dirección/datos.

Otra idea sería comprimir el contenido de la ROM a menos de 256 KiB y luego conectar un RP2040 para usarlo con, por ejemplo, PicoROM. (OSDSYS, PS2LOGO, PS1DRV y el reproductor de DVD podrían tener que cargarse desde otro lugar).
[/CITA]
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Hello, I find your proposal very interesting. If you need someone to test, I am at your complete disposal. I have plenty of time at the moment. If you are interested in my proposal, then we are here at your service. Best regards.
 
El_isra

El_isra

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Tschicki said:
The sad reality is that (currently) it’s not possible to launch applications stored on rom1.
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Just making sure. Are you aware that rom0:ADDDRV must be executed? That driver registers rom1 against ROMDRV
 
Tschicki

Tschicki

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El_isra said:
Hello there

Decided to join the discussion here
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Well hello there!
I feel very honored to see that such a famous PS2 developer like you is commenting on my worklog! First of all I would like to thank so much for releasing PS2BBL, without it none of the custom bios work so far would have been possible!

Sadly I don't have an answer to your question! I was mainly developing the hardware side of the mod and helped out with testing, but @Epaminondas is the mastermind behind the modified bios. I know roughly how it was done, but by far not enough to be involved in any discussion about the software side of things.

But seeing you comment here I assume that you are interested in bringing this mod to the next level! Surely there is still a lot to discover and having access to rom1 would make a lot of space for more homebrew. I cannot even comprehend the knowledge you must have about the PS2's architecture, so I'm sure you have lots of ideas in mind that nobody thought about so far. While changing the bios chip is not the easiest task for most, with some of your magic this could be the next big thing for PS2 homebrew!
If you have some questions about the hardware side, let me know. I'm also happy to help you test things that cannot be tested in PCSX2 on my 79004 mainboard!

Lightning said:
Ahh shoot! Well that's too bad, but as usual necessity is the mother of invention, and you seem to have come up with a pretty innovative solution!

Did you ever end up finding out the voltage for those JoyCon sticks?
Click to expand...
Thanks! For the analog sticks I tried 3 versions now: Gulikit, the retroid sticks @thedrew recommended and some other analog sticks from aliexpress. The Gulikit one for sure are 1.8V, the retroid sticks I was running on 3.3V and the aliexpress ones currently run on 1.8V (but should support 3.3V?). My favorites so far are the aliexpress ones, but I designed the gamepad so that I could easily switch from 1.8V to 3.3V via a jumper.

mixa232323 said:
Where can I get a modified BIOS?
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Sadly there is no modified bios available, as I think it's not quite legal to share it, especially here. But soonish there might be instructions or other means available to allow everyone to patch the bios.


Recently I feel like things are starting to move regarding the bios modifications and I'm super exited for what's to come! Soon I will also write another update regarding my portable, as there was some progress even though my time in summer is quite limited!
 
El_isra

El_isra

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Tschicki said:
Well hello there!
I feel very honored to see that such a famous PS2 developer like you is commenting on my worklog! First of all I would like to thank so much for releasing PS2BBL, without it none of the custom bios work so far would have been possible!
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You'll make me blush xd. I'm just a boy that grew up with the PS2 and luckily ended up making software for it as a hobby.
I don't fit in the "famous PS2 developer" category I believe XD.


PS2BBL can serve as a bootloader, yes.
actually, we can tweak it a bit for better integration with the concept of reprogrammable boot ROM. Wich only existed officially for DTL-T models.

I'm curious on @Epaminondas approach for manipulating the boot ROM. Specially how he dealt with the problem of the files that need to be on fixed offsets so the bootstrap program on the image begining can find them.
 
Mister M

Mister M

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El_isra said:
You'll make me blush xd. I'm just a boy that grew up with the PS2 and luckily ended up making software for it as a hobby.
I don't fit in the "famous PS2 developer" category I believe XD.


PS2BBL can serve as a bootloader, yes.
actually, we can tweak it a bit for better integration with the concept of reprogrammable boot ROM. Wich only existed officially for DTL-T models.

I'm curious on @Epaminondas approach for manipulating the boot ROM. Specially how he dealt with the problem of the files that need to be on fixed offsets so the bootstrap program on the image begining can find them.
Click to expand...
I talked to Epaminondas, he is about to release the file repository to modify the BIOS. He sent me the files so I could test them on the PSX2 emulator and they worked perfectly. We are eagerly awaiting the open source of this BIOS. Another thing, it would be interesting if we could get more space in the BIOS, since it is only possible to use 4mb on the console.
 

stuckpixel

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Excellent project! Your determination on this, and the methodical "do one piece at a time" approach is awesome and I can't wait to see more. On that note, I'm a bit of an rp2040 enthusiast, and I'd be happy to help with it if you're willing. I think the PIO and DMA subsystems could be used to help reduce the load on the CPU quite significantly, and provide some nicer abstractions for your usecase. Keep up the good work :)
 
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uyjulian

uyjulian

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I think it would be interesting to get PS2MADD (or something else similar) support integrated into DECKARD emulator such that you can pretend that commonly available e.g. 8MB QSPI flash or SD/eMMC is memory mapped ROM. Then lower the parallel flash ROM capacity (to more common chips) to hold just the modified DECKARD emulator (or emulate the flash on RP2040 with PicoROM off the same QSPI flash).

Or solder a memory card containing the next boot program to the memory card port, but you lose a port that way.
 
El_isra

El_isra

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Mister M said:
Another thing, it would be interesting if we could get more space in the BIOS, since it is only possible to use 4mb on the console.
Click to expand...
Since we are already replacing the ROM, we surely can deal with that. It would require replacing the ROMDRV module. Wich we already have an open source version.

I would like to hear @uyjulian ideas on this regard.
 
Mister M

Mister M

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uyjulian said:
You could probably put some ROM in dev9 address space (e.g. ACDEV)
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Something interesting that I had mentioned to Epaminondas is about this possibility of increasing the size of the PS2's RAM, for those of you who are PS2 programmers, it would be interesting to add something like this in some mod, in fact I don't know about the possibility of using it in a new BIOS or something like that, it's not my area, but it's another thing that can revolutionize the PS2 scenario.

 
Epaminondas

Epaminondas

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Hello guys! How are you? I'll be sharing all my work on the custom ROM on this forum. It's very rudimentary, because I did it at the time thinking it would be useless, hehe.

I see that guy is here, great to see that, he created PS2BBL, and PS2BBL was the key piece of this work, I can't help but imagine what he can do for this project.
 
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