On Mon, Feb 03, 2020 at 01:50:25PM -0500, Gene Heskett wrote: > I have no "leveerage" with raspbian. They officially have zero support > for a realtime kernel. 4 posts to their forum in threads related, over4 > days have not elicited a reply from anyone. > > I have no problems building kernels on the rpi4b as I two SSD'd mounted > on sata-usb3 cables, so a full kernel bulld is under an hour in wall > time. I also, because its only a 2G pi, have a 10G swap partition > mounted, and the swapfile turned off to reduce pressure on the u-sd > card. > > The pi-4b is a whole new critter worth looking at. > > It is supported upstream by any linux-rt kernel newer than 4.14 although > 4.14's support for the mali gfx isn't quite fully baked until 4.19.y.
Ehm, I was pretty sure all Raspberry Pi models have broadcom videocore graphics, and certainly not mali. > I am actually running a > > Linux rpi4.coyote.den 4.19.71-rt24-v7l+ #1 SMP PREEMPT RT Thu Oct 10 > 15:22:22 EDT 2019 armv7l GNU/Linux > > right now, but a /boot/dts/overlays directory has apparently been removed > from newer ones, and I'm trying to find a workaround, or make an arm64 > boot work and rebuild LinuxCNC to run on a 64 bit build. I'd settle for > either scenario. > > So it would appear Len. And I'll repeat, the original 10.0 netinstall > Just Worked, and felt dead stable, but now a 10.2 of this buster doesn't > even try to boot. The main diff is that there is now a pair of ssd's on > sata adaptors plugged into the usb-3 ports with a total of 360G > available as scratchpad workspaces. I don't see how adding USB disks should change anything. Did you upgrade the working 10.0 system, or did you do a new image? Because the only think that makes sense to me is that the 10.0 image wasn't a pure Debian image, but rather one modified enough for RPi4 operation. > Thanks Len, for any enlightement. I don't have a 4 (only a 2 and 3 so far). What I have read made me think that it simply should not work so far with Debian. There appears to be some unofficial modified images out that that should work. -- Len Sorensen
