Poseidon USB Stack as Open Source?

Chris Hodges has offered to release the Poseidon USB stack to the AROS community under the APL license. This could could be beneficial for classic and os4 users as well.

Read more here

@orgin

Using PCI USB2 cards and having isochronous transfers would be nice...

Could it be usefull to os4 ??

original link is long gone. didn't he give it to AROS in the end or something?

@NinjaCyborg
https://github.com/aros-development-team/AROS/tree/master/rom/usb

MorphOs are using it , they are claiming it as their usb stack of choice on their latest update 3.19. i dont know if they are bundleing it as open source within their OS

@Crumb

isochronous transfers is supported in OS4.1 usb stack.
don't remember if its in beta or released.

@orgin

I think most USB problems it’s not related to the USB stack,
XE/XE/Micro lacked pull up/down resistors on some of the signal lines.

some of the computers, have problems with underpowered USB ports.

I think benefit might be legacy software, iomega had some USB software I remember,
and maybe, I don’t know about gamepad support, but Amiga Input, has a flawed design.

@Swisso

AFAIR Poseidon was already the MorphOS USB stack before it was open sourced for AROS, so their licence is different.

Even if someone would port Poseidon to AmigaOS 4.x: What's the point of having an alternative, but unusable USB stack?

Of course the Sirion USB hardware drivers of AmigaOS 4.x can't be used with Poseidon, nor the other way round, and all of them would have to be reimplemented from scratch for Poseidon, additionally to porting Poseidon itself, to be able to use it on AmigaOne SE/XE/µA1, Sam4x0, X1000, X5000, A1222+, ... systems.

Maybe there are some AmigaOS 3.x/m68k Poseidon hardware drivers which do work emulated on AmigaOS 4.x on classic Amigas, but for all other systems an AmigaOS 4.x port of Poseidon would be completely useless.

@joerg did anyone suggest that?

@joerg
I don't know what Sirion drivers are but considering that USB HCD interface is pretty standard (there are only about 4 kinds) so getting hardware drivers should not be a problem. When emulating USB parts of these machines I can usually pick the existing emulation appropriate for the machine and map it somewhere then all OS drivers are happy so this also means the existing Posiedon drivers should likely also work. Thus porting it would be less about drivers and more about finding out how it would fit in the system if the application side APIs differ.

MorphOS may have a fork from the author as they don't list it on their open source page and not sure if they have additional fixes compared to the AROS version. I remember something about isochronous transfers that was needed for usb-audio but it does not work with the emulated USB in QEMU so I don't know about that but heard it works on real machine. Maybe that's missing from the AROS version but I'm not sure.

@balaton

The different kinds of USB chipsets I guess, but its also all software that use Amiga Input, that wont work. if the USB stack is replaced, and some flatbed scanners.

@balatonQuote:
Yeah, I don't think Poseidon on MorphOS has anything from the AROS version. Poseidon has been part of MorphOS since the very beginning... I've been using it at least with MorphOS 1.x versions from 2003 and quite likely it's been there even before that.

When doing a quick search for words in MorphOS release notes, there are "Poseidon" mentions in 7 files, and "USB" mentions in 22 files. So they have been constantly improving it, and yes, isochronous transfers support (mainly for USB audio) came in 3.10. The current main Poseidon version has been marked as 4.5 (17.11.2022), but separate classes have much higher version numbers too.

Edit: quick googling gave this, which tells that Chris Hodges himself wrote Poseidon for MorphOS and the driver for Pegasos in 2003:
https://www.osnews.com/story/2996/morphos-gets-a-usb-stack/

Edit 2: and Chris told:
"Although claimed otherwise, I was never contacted about Poseidon for OS4. Ben Hermans stated in public that they would not abandon the efforts of the Sirion Stack developers in favor of my work. This is something I understand well and accept. Therefore, I did not offer Poseidon for inclusion into OS4 myself."

@balaton
Quote:Poseidon (used by MorphOS) and Sirion (used by AmigaOS 4.x) are the 2 most used USB stacks on AmigaOS, both were available for older AmigaOS versions already, for different USB hardware.
Most developers of classic Amiga USB hardware used Poseidon for the software part.

Even on a system like the AmigaOne XE/SE/µA1 which has standard PCI USB you need special drivers: The A1 uses the buggy VIA 686B south bridge and has additional USB related bugs on the motherboard which require workarounds in the drivers.
Of course it's no problem when running the AmigaOne version of AmigaOS 4.x on QEmu, but on real, buggy hardware a standard driver does't work.

On embedded/SoC CPUs like 4x0 or QorIQ standard PCI USB OHCI/UHCI/EHCI/XHCI drivers usually don't work either but you need special ones for each SoC instead.

On classic Amigas each Zorro II/III, clock port, etc., custom USB hardware controller needs a custom driver.
Even if you use a PCI USB controller with a Zorro<->PCI bridge like the Prometheus, Firestorm or Mediator in a classic Amiga you needed special drivers for the different ways those PCI bridges work on AmigaOS <= 3.9.
AmigaOS 4.x includes support for those Zorro<->PCI bridges in the kernel and all are accessed with the same expansion.library API, but that doesn't change the hardware limits of the bridges like no DMA support.

The only AmigaOS systems where standard PCI USB drivers work are probably the X1000 (AMD SB600 south bridge) and PegasosII (VIA VT8231).


Of course not only the hardware driver APIs but the OS/application APIs are different between Poseidon and Sirion as well, and unless you additionally implement a Sirion<->Poseidon API wrapper a port of Poseidon to AmigaOS 4.x, incl. implementing all required hardware drivers for Poseidon, would still be useless...