On Tue, Jan 14, 2020 at 4:04 PM Gene Heskett <gheskett@xxxxxxxxxxx> wrote: > > On Tuesday 14 January 2020 12:15:37 Paul Thomas wrote: > > > On Tue, Jan 14, 2020 at 11:24 AM Gene Heskett <gheskett@xxxxxxxxxxx> > wrote: > > > On Tuesday 14 January 2020 08:54:30 Paul Thomas wrote: > > > > On Sun, Jan 12, 2020 at 9:44 PM Gene Heskett > > > > <gheskett@xxxxxxxxxxx> > > > > > > wrote: > > > > > On Friday 10 January 2020 15:14:30 Sebastian Andrzej Siewior > wrote: > > > > > > Dear RT folks! > > > > > > > > > > > > I'm pleased to announce the v5.4.10-rt5 patch set. > > > > > > > > > > > > Changes since v5.4.10-rt4: > > > > > > > > > > > > - Dick Hollenbeck reported that the printk rework had a > > > > > > negative impact on the 8250 driver if not used as a console. > > > > > > Patch by John Ogness. > > > > > > > > > > > > Known issues > > > > > > - None > > > > > > > > > > > > The delta patch against v5.4.10-rt4 is appended below and can > > > > > > be found here: > > > > > > > > > > > > > > > > > > https://cdn.kernel.org/pub/linux/kernel/projects/rt/5.4/incr/p > > > > > >atch -5.4 .10-rt4-rt5.patch.xz > > > > > > > > > > > > You can get this release via the git tree at: > > > > > > > > > > > > > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-deve > > > > > >l.gi t v5.4.10-rt5 > > > > > > > > > > I grabbed a copy of this, then turned off anything not needed to > > > > > run LinuxCNC on an rpi4 in armhf config. Then I noted its make > > > > > had a make deb-pkg option. But it isn't making what I told it > > > > > to make as I'm sitting here watching it ALL go by. Did I miss > > > > > something in a make menuconfig that triggered a make all? It > > > > > was supposedly set for armhf. But I'm even seeing x86 stuff go > > > > > by. Obviously I know just enough to screw it up. Point me at the > > > > > right docs for arm builds please. > > > > > > > > > > Hi Gene, > > > > > > > > I recently stumbled into deb-pkg, and it's awesome building up the > > > > source and standard debian packages all in one command, but it > > > > takes the same arguments as a standard make. For rpi4 this is > > > > arm64 not armhf so you probably want something like below to > > > > configure for arm64 > > > > > > armhf (32 bit) runs fine in on an RPI4, been doing it for a couple > > > months now. With a 32 bit stack frame, context switch latencies are > > > several microseconds better which linuxcnc loves. However with mesa > > > interface cards handling all the sub-millisecond stuffs and using > > > preempt-rt running in userspace, it all works quite well as the max > > > latency stays below 200 microseconds 99.99% of the time. Thats well > > > within the servo-thread time of 1 millisecond the mesa cards need. > > > > Ah, makes sense. > > > > > > If you are doing this on the rpi4 you don't need the > > > > CROSS_COMPILE= option.[1][2] make -j4 ARCH=arm64 > > > > CROSS_COMPILE=aarch64-elf- defconfig > > > > Or if the kernel you're already running has a /proc/config.gz you > > > > can use that directly (zcat /proc/config.gz > .config). > > > > Then you can use the main make. > > > > > > The kernel I an running was built, by me (queue the raspberry > > > noises), with only the ondemand governer so while its working, its > > > stuck in low gear. And the pi has plenty of cooling. > > > > > > that kernel running now is a 4.19.71-rt24-v7l+ #1 SMP PREEMPT RT, > > > but there has since been added another video speedup option, so ATM > > > I am trying to build a 4.19.94-rt38 announced last week. But the git > > > clone I pulled doesn't have the rt patch. And pulling that patch > > > with curl today fails: > > > > > > pi@rpi4:/media/pi/workspace $ curl > > > http://www.kernel.org/pub/linux/kernel/projects/rt/4.19/patch-4.19.9 > > >4-rt38.patch.xz > > > > Hmm, this seems fine for me: > > wget > > https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.19.94.tar.xz > > tar xf linux-4.19.94.tar.xz > > cd linux-4.19.94/ > > wget > > http://www.kernel.org/pub/linux/kernel/projects/rt/4.19/patch-4.19.94- > >rt38.patch.xz > > unxz patch-4.19.94-rt38.patch.xz > > patch -p1 < patch-4.19.94-rt38.patch > I blew away my git clone and followed this, which all worked to here, > but: > > make ARCH=armhf defconfig Sorry that was a cut/paste typo, there is no arch/armhf just arm, so you want make ARCH=arm defconfig I had tried the command that's why it was in my history and thus the copy/paste mistake. I believe how this works is the kernel just has CONFIG_AEABI=y as the ABI config, then userspace compilers have to decide if they want to compile for a hardware floating point or not, and what debian has decided is that they would have a special architecture just for hardfloat: https://wiki.debian.org/ArmHardFloatPort thanks, Paul
