Remove Raspberry Pi userland

[zoltanvb]

Description

Userland was added at: #8132
However, its only use was with CRTSwitchRes together with VideoCore. Over the times, the legacy VideoCore drivers have lost usage as nowadays Mesa supports the VideoCore IV chip in RPi 0..3, and RPi 4 and/or 64-bit was never supported.

Option is kept to use the legacy drivers, but it is now utilized from the OS. It is only required if --enable-videocore is used to configure the build, and in this case userland install was required anyway, since only gfx/video_crt_switch.c used it from the RA source tree.

Tested building and basic RA operation.

Related Issues

Fixes #9966 . I will add a few words to RPi guide to cover installation of userland.

Reviewers

A confirmation would be nice that Lakka builds that still use videocore (GPICase and Pi02GPi) will still be able to build.

[LibretroAdmin]

@alphanu1 Is it OK to merge this or is the userland actually used for something still?

[alphanu1]

This was used to support video core 3 as well. If the user who has removed this can confirm CRT switching still works for PI2 and 3 using video core support then I guess it fine.

Just need to highlight that as it may cause regression.

[zoltanvb]

Change is quite trivial, VC source is still used, just from somewhere else, but certainly it is better to validate. It seems I can not test it unfortunately, as I read it not only needs the RPi + CRT, but an additional HDMI converter as well, since none of the Pi models builtin composite is suitable for SwitchRes, is that correct understanding?

Given that the last compilation failure was not reported for approx. 8 months (see #15971 ), probably there are not so many users around that would frequently get new builds. But, if there is anyone reading this who can test RPi + CRTSwitchRes, I can provide a new build if you tell me the environment.

[LibretroAdmin]

@alphanu1 So what's the status on this? By merging this are we removing support for something related to CRT SwitchRes or are we good here?

[alphanu1]

@LibretroAdmin, It possibly could. I no longer have a PI 2 or a PI 3. So, I cannot confirm any regression that this might cause. After the change to Calamity's switchres code. The PI will work with x11. However, if the source for the PI video driver is removed (part of above). Then, if the distro installed on the PI does not contain this RetroArch will not compile unless you install the above.

That being said CRT SwirchRes does not look for these in sources in the shared library folders. It points to the RA source folder "include/userland/interface/vmcs_host/". So removing this will break CRT SwitchRes for the PI.