Can you program GPUs and do you want to become a HERO? #linuxphone
community needs your help.

We are trying record video, and have most pieces working, but one is
missing: fast enough debayering. That means about 23MB/sec on #librem5.

Debayering is not hard; camera images have subpixels split on two
lines, which need to be corrected. They also use different color
representation, but that's fixable by some table lookup and two matrix
multiplies.

Librem 5 has Vivante GPU, 4 in-order CPU cores and 3GB RAM. My feeling
is that it should be fast enough for that. If task is for some reason
impossible, that would be good to know, too.

Image data looks like this

RGRGRG...
xBxBxB...
.........
.........

Task is to turn that into usual rgbrgb.... format. rgb = RGB * color
matrix, with table lookups for better quality. I can fix that once I
get an example.

I'm looking for example code (#pinephone would work, too), reasons it
can not be done... and boosts if you have friends that can program
GPUs. #gpu#opensource

💻 FreeBSD CUDA drm-61-kmod 💻

"Just going to test the current pkg driver, this will only take a second...", the old refrain goes. Surely, it will not punt away an hour or so of messing about in loader.conf on this EPYC system...

- Here are some notes to back-track a botched/crashing driver kernel panic situation.
- Standard stuff, nothing new over the years here with loader prompt.
- A few directives are specific to this system, though may provide a useful general reference.
- The server has an integrated GPU in addition to nvidia pcie, so a module blacklist for the "amdgpu" driver is necessary (EPYC 4564P).

Step 1: during boot-up, "exit to loader prompt"
Step 2: set/unset the values as needed at the loader prompt

unset nvidia_load
unset nvidia_modeset_load
unset hw.nvidiadrm.modeset
set module_blacklist=amdgpu,nvidia,nvidia_modeset
set machdep.hyperthreading_intr_allowed=0
set verbose_loading=YES
set boot_verbose=YES
set acpi_dsdt_load=YES
set audit_event_load=YES
kern.consmsgbuf_size=1048576
set loader_menu_title=waffenschwester
boot

Step 3: login to standard tty shell
Step 4: edit /boot/loader.conf (and maybe .local)
Step 5: edit /etc/rc.conf (and maybe .local)
Step 6: debug the vast output from kern.consmsgbuf logs

#freebsd #nvidia #cuda #gpu #engineering #terminal #saturday