Xenomai on rPi

CM4/rPi4

Project maintained by George117 Hosted on GitHub Pages — Theme by mattgraham

The folowing steps are done on the host(Ubuntu)

1. Linux

1.1. Clone the rPi 5.15 branch of Linux

git clone --branch rpi-5.15.y https://github.com/raspberrypi/linux

1.2. Checkout 5.15.52(close/same as dovetail patch)

cd linux

git checkout 2a4746398db05d1d71e00c8f2cccdb85b2d3ca3c

cd ..

2. Xenomai

2.1 Download Xenomai v3.2.1

wget https://github.com/George117/rPi_Xenomai/releases/download/5.15.52/xenomai-v3.2.1.tar.bz2

tar xjvf xenomai-v3.2.1.tar.bz2

2.2 Download Dovetail v5.15.51 patch

wget https://github.com/George117/rPi_Xenomai/releases/download/5.15.52/patch-5.15.51-dovetail1.patch

3. Patch the linux source code

cd linux/

patch -p1 < ../patch-5.15.51-dovetail1.patch  2>&1 | tee patch_log.txt

4. Fix the files where the patch did not apply

Full log: patch_log.txt

Hunk #7 FAILED at 177.
1 out of 7 hunks FAILED -- saving rejects to file arch/arm/include/asm/irqflags.h.rej

Hunk #1 succeeded at 30 (offset 1 line).
Hunk #2 succeeded at 666 (offset 230 lines).
Hunk #3 FAILED at 458.
Hunk #4 succeeded at 709 (offset 238 lines).
Hunk #5 succeeded at 717 (offset 238 lines).
Hunk #6 FAILED at 489.
Hunk #7 succeeded at 821 (offset 238 lines).
Hunk #8 succeeded at 850 (offset 246 lines).
Hunk #9 succeeded at 860 (offset 246 lines).
Hunk #10 succeeded at 933 (offset 248 lines).
Hunk #11 succeeded at 1017 (offset 258 lines).
Hunk #12 succeeded at 1116 (offset 267 lines).
Hunk #13 succeeded at 1126 (offset 267 lines).
Hunk #14 succeeded at 1307 (offset 337 lines).
Hunk #15 FAILED at 1042.
3 out of 15 hunks FAILED -- saving rejects to file drivers/dma/bcm2835-dma.c.rej

Hunk #1 FAILED at 102.
1 out of 1 hunk FAILED -- saving rejects to file drivers/irqchip/irq-bcm2835.c.rej

Hunk #1 FAILED at 1041.
Hunk #2 succeeded at 1080 (offset 14 lines).
Hunk #3 succeeded at 1346 (offset 14 lines).
Hunk #4 succeeded at 1429 (offset 14 lines).
1 out of 4 hunks FAILED -- saving rejects to file drivers/spi/spi-bcm2835.c.rej

Fixed files (no guarantees)

./arch/arm/include/asm/irqflags.h

./drivers/dma/bcm2835-dma.c

./drivers/irqchip/irq-bcm2835.c

./drivers/spi/spi-bcm2835.c

files.zip

5. Prepare kernel with xenomai

../xenomai-v3.2.1/scripts/prepare-kernel.sh  --arch=arm64 --linux=./

No log is displayed

6. Build Config

Configs rPi 4/400/CM4:

KERNEL=kernel8

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- bcm2711_defconfig

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig

Edit the kernel config in menuconfig (minimal setup) and Save

Kernel features —> Timer frequency 1000Hz
General setup —> (-v7l-xeno3) Local version - append to kernel release

Uncheck the following settings:

CPU powermanagement –> CPU Frequency scaling –> [] CPU Frequency scaling  
(
headsup -> this disables the governor -> default cpufreq = 600Mhz
Depending on your needs maybe its better to set the governor to Performace by default
)

CPU powermanagement –> CPU idle PM support []
MemoryManagament options -> [] Allow for memory compaction
Kernel hacking -> Generic Kernel Debugging Instruments -> KGDB: kernel debugger[]

7. Build the kernel

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image modules dtbs -j 24

Note: If you dont see this message, run the command again(only for your peace of mind, the image exists :) )

Before:

After:

8. Install the created image on rPi

8.0 CM4 -> rpiboot

https://github.com/raspberrypi/usbboot/blob/master/Readme.md#building

8.1 rPi 4 -> SDCard adapter

8.2 Identify CM4/SDCard partition `lsblk`

sdb
   sdb1(boot)
   sdb2(root)

cd linux

mkdir mnt

mkdir mnt/fat32

mkdir mnt/ext4

sudo mount /dev/sdb1 mnt/fat32

sudo mount /dev/sdb2 mnt/ext4

sudo env PATH=$PATH make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- INSTALL_MOD_PATH=mnt/ext4 modules_install

sudo cp mnt/fat32/$KERNEL.img mnt/fat32/$KERNEL-backup.img

sudo cp arch/arm64/boot/Image mnt/fat32/$KERNEL.img

sudo cp arch/arm64/boot/dts/broadcom/*.dtb mnt/fat32/

sudo cp arch/arm64/boot/dts/overlays/*.dtb* mnt/fat32/overlays/

sudo cp arch/arm64/boot/dts/overlays/README mnt/fat32/overlays/

sudo umount mnt/fat32

sudo umount mnt/ext4