Raspberry Pi 4

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strawberrytau
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Raspberry Pi 4

Post by strawberrytau » Fri Jul 05, 2019 10:09 pm

The new RPi 4 must have enough power for butter smooth Beeb emulation. Has anyone tried this yet?

Tanker_5455
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Re: Raspberry Pi 4

Post by Tanker_5455 » Wed Jul 31, 2019 6:47 pm

I'm running other emulators on it, and it works as a charm, I think that emulating the Beeb won't be an issue at all.

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sbadger
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Re: Raspberry Pi 4

Post by sbadger » Fri Aug 02, 2019 2:49 pm

tbh the original Pi was more than capable. apparently the new pi4 can do Dreamcast
So many projects, so little time...

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Re: Raspberry Pi 4

Post by BeebMaster » Wed Aug 14, 2019 12:38 pm

My PSU and monitor lead arrived today, but the Pi 4 itself is still on back-order for a few weeks.

Hopefully by then somebody will have got a full Ubuntu install working on it. I recall the Pi 3 was a bit hopeless at it when I tried in the early days. I'd like to replace my Pi 2 with Raspbian (which runs all my NFS shares) with a Pi 4 with Ubuntu, which I am hoping will have much better Ethernet.

I see that the recommended PSU is now 3 amps - does that mean we're not having to use powered USB hubs whenever we plug something into it?
Image

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Wed Aug 14, 2019 1:59 pm

Sadly the Raspberry Pi 4, running Raspbian Buster, currently has a graphics driver bug (the glLogicOp function is broken) which affects BBC BASIC for SDL 2.0; specifically the OR, AND and XOR plotting modes (GCOL 1 to GCOL 4) don't work. This causes issues in the IDE and a number of the supplied example programs (e.g. 'jigsaw.bbc'). BBC BASIC remains largely usable despite this problem, but hopefully it will be fixed in a future update to Buster.

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Re: Raspberry Pi 4

Post by dp11 » Fri Aug 16, 2019 11:33 am

Richard Russell wrote:
Wed Aug 14, 2019 1:59 pm
Sadly the Raspberry Pi 4, running Raspbian Buster, currently has a graphics driver bug (the glLogicOp function is broken) which affects BBC BASIC for SDL 2.0; specifically the OR, AND and XOR plotting modes (GCOL 1 to GCOL 4) don't work. This causes issues in the IDE and a number of the supplied example programs (e.g. 'jigsaw.bbc'). BBC BASIC remains largely usable despite this problem, but hopefully it will be fixed in a future update to Buster.
My understanding is XOR is now supported. Is there another op that also doesn't work ?

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Fri Aug 16, 2019 11:59 am

dp11 wrote:
Fri Aug 16, 2019 11:33 am
My understanding is XOR is now supported. Is there another op that also doesn't work ?
Since when? I don't have a RPi4 myself and I'm relying on reports from other users. I'm somewhat surprised if they've sorted XOR but not the others (OR, AND etc.) because I thought the fix implemented them all. Certainly fixing XOR alone would be useless for BBC BASIC because OR (GCOL 1,n) and AND (GCOL 2,n) are just as important.

On the other hand I've posted about this at the Raspberry Pi forum and nobody there has replied that it's already been fixed.

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Re: Raspberry Pi 4

Post by dp11 » Fri Aug 16, 2019 12:10 pm

I don't know about OR and AND, but I suspect they are also fixed. The driver certainly has had the XOR fix for a while now.

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Re: Raspberry Pi 4

Post by Richard Russell » Fri Aug 16, 2019 10:56 pm

dp11 wrote:
Fri Aug 16, 2019 12:10 pm
I don't know about OR and AND, but I suspect they are also fixed. The driver certainly has had the XOR fix for a while now.
I'll ask the user who reported it to update his RPi4 (although it was quite new anyway).

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Sat Aug 17, 2019 9:57 am

Richard Russell wrote:
Fri Aug 16, 2019 10:56 pm
I'll ask the user who reported it to update his RPi4 (although it was quite new anyway).
He reports that there is no change. Having done:

Code: Select all

sudo apt-get update
sudo apt-get dist-upgrade
All the glLogicOp modes he tested (OR, AND and XOR) are still non-functional. Is there anything else he could/should do?

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Re: Raspberry Pi 4

Post by dp11 » Sat Aug 17, 2019 10:02 am

If they are happy to help can they see if the pointer in libre office works. Ie just to confirm that they have the latest driver. I'll ask my friends at pi if they know of anything else.

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Re: Raspberry Pi 4

Post by hoglet » Sat Aug 17, 2019 10:07 am

dp11 wrote:
Sat Aug 17, 2019 10:02 am
I'll ask my friends at pi if they know of anything else.
Dominic, in case you missed this, there is more info in this thread:
https://www.raspberrypi.org/forums/view ... p?t=248340
Last edited by hoglet on Sat Aug 17, 2019 10:07 am, edited 2 times in total.

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Re: Raspberry Pi 4

Post by dp11 » Sat Aug 17, 2019 10:13 am

I did miss that thread. Thanks for the pointer

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Re: Raspberry Pi 4

Post by dp11 » Sat Aug 17, 2019 10:31 am

I'm pretty sure that fix is in the latest driver.

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Sat Aug 17, 2019 12:43 pm

dp11 wrote:
Sat Aug 17, 2019 10:31 am
I'm pretty sure that fix is in the latest driver.
So how do you install that driver other than doing 'apt-get dist-upgrade', which seemingly had no effect? Is there something else you need to do to enable it (whilst the VC4 driver on the RPI 3 needed explicitly enabling, my understanding was that the V3D driver is enabled by default on the RPi 4)?

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Re: Raspberry Pi 4

Post by dp11 » Sat Aug 17, 2019 1:02 pm

The only reason I think the fix is in the latest driver is that libre office works. I will try and investigate.

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hoglet
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Re: Raspberry Pi 4

Post by hoglet » Sat Aug 17, 2019 1:10 pm

I've had a look at the Mesa driver reposirtory.

The fix being talked about is not included in any of the Mesa 19.1.x versions. It should appear in Mesa 19.2, which is still in development.

The only way to test this now would be to build your own version of the Mesa library from the current master branch. There are some instuctions for doing that here:
https://github.com/anholt/mesa/wiki/VC4 ... an-upgrade

Code: Select all

sudo apt-get install \
    flex bison python3-mako \
    libxcb-dri3-dev libxcb-dri2-0-dev \
    libxcb-glx0-dev libx11-xcb-dev \
    libxcb-present-dev libxcb-sync-dev \
    libxxf86vm-dev libxshmfence-dev \
    libxrandr-dev \
    libxdamage-dev libxext-dev libxfixes-dev \
    x11proto-dri2-dev x11proto-dri3-dev \
    x11proto-present-dev x11proto-gl-dev \
    x11proto-xf86vidmode-dev \
    libexpat1-dev libudev-dev gettext

git clone git://anongit.freedesktop.org/mesa/mesa
cd mesa
meson build \
    --prefix=/usr \
    --libdir=/usr/lib/arm-linux-gnueabihf \
    -Dbuildtype=release \
    -Dplatforms=x11,drm,surfaceless \
    -Ddri-drivers= \
    -Dgallium-drivers=vc4,v3d
ninja -C build \
sudo -E ninja -C build install
There are no guarantees that this will work, as it's possible other components will need to be updated at the same time. It may leave the system in an unstable state, so either take a backup first, or try it on a test system that you don't mind breaking.

Dave

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Sat Aug 17, 2019 1:51 pm

hoglet wrote:
Sat Aug 17, 2019 1:10 pm
The fix being talked about is not included in any of the Mesa 19.1.x versions. It should appear in Mesa 19.2, which is still in development.
Thanks for the clarification. On that basis I can't be optimisitic that it will be in Raspbian any time soon.
The only way to test this now would be to build your own version of the Mesa library from the current master branch.
It's unlikely that I could make that work (not least because I haven't got a RPi 4) but perhaps somebody else could manage it and make it available for download. I could then give instructions to BBC BASIC users for how to install it. Any takers?!

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Re: Raspberry Pi 4

Post by dp11 » Sat Aug 17, 2019 6:22 pm

It's possible that fix was back ported into the drive raspberry pi released to fix libre office.

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Sat Aug 17, 2019 7:54 pm

dp11 wrote:
Sat Aug 17, 2019 6:22 pm
It's possible that fix was back ported into the drive raspberry pi released to fix libre office.
Does that help me?

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Richard Russell
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Re: Raspberry Pi 4

Post by Richard Russell » Sun Aug 18, 2019 10:35 am

dp11 wrote:
Sat Aug 17, 2019 6:22 pm
It's possible that fix was back ported into the drive raspberry pi released to fix libre office.
We now have the answer from the horse's mouth at the Raspberry Pi forum. The LibreOffice 'fix' wasn't achieved by implementing glLogicOp() at all, "It was more of a workaround. Something to do with switching from a gtk 2 to a gtk 3 backend is all I remember". So glLogicOp() never has been implemented on the RPi 4 and will only be when the fix in Mesa is incorporated in Raspbian.

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Re: Raspberry Pi 4

Post by dp11 » Sun Aug 18, 2019 10:38 am

Excellent thanks for letting me know.

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Re: Raspberry Pi 4

Post by dp11 » Thu Aug 22, 2019 8:45 pm

Mesa issue will be fixed in 19.2. They're aiming to have a release ready by the 10th of September. So shortly afterwards there should be a Pi release.

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