移植实时Linux方案Xenomai到i.MX ARMv7平台 (Enable real-time Linux Xenomai on i.MX ARMv7 Platform)

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    Xenomai is real-time framework, which can run seamlessly side-by-side Linux as a co-kernel system, or natively over mainline Linux kernels (with or without PREEMPT-RT patch). The dual kernel nicknamed Cobalt, is a significant rework of the Xenomai 2.x system. Cobalt implements the RTDM specification for interfacing with real-time device drivers. The native linux version, an enhanced implementation of the experimental Xenomai/SOLO work, is called Mercury. In this environment, only a standalone implementation of the RTDM specification in a kernel module is required, for interfacing the RTDM-compliant device drivers with the native kernel. You can get more detailed information from Home · Wiki · xenomai / xenomai · GitLab  

    I have ported xenomai 3.1 to i.MX Yocto 4.19.35-1.1.0, and currently support ARMv7 and tested on imx6ulevk/imx6ull14x14evk/imx6qpsabresd/imx6dlsabresd/imx6sxsabresdimx6slevk boards. I also did stress test by tool stress-ng on some boards.

     You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm.git, and git checkout Linux-4.19.35-1.1.0. (which inlcudes all patches and bb file) and add the following variable in conf/local.conf before build xenomai by command bitake xenomai. 

XENOMAI_KERNEL_MODE = "cobalt" 

PREFERRED_VERSION_linux-imx = "4.19-${XENOMAI_KERNEL_MODE}"

IMAGE_INSTALL_append += " xenomai"

DISTRO_FEATURES_remove = "optee"

or
XENOMAI_KERNEL_MODE = "mercury"

PREFERRED_VERSION_linux-imx = "4.19-${XENOMAI_KERNEL_MODE}"

IMAGE_INSTALL_append += " xenomai"

DISTRO_FEATURES_remove = "optee"

If XENOMAI_KERNEL_MODE = "cobalt", you can build dual kernel version. And If XENOMAI_KERNEL_MODE = "mercury", it is single kernel with PREEMPT-RT patch.

The following is test result by the command (/usr/xenomai/demo/cyclictest -p 50 -t 5 -m -n -i 1000

//Mecury on 6ULL with stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 128M --metrics-brief
policy: fifo: loadavg: 6.08 2.17 0.81 8/101 534

T: 0 (  530) P:99 I:1000 C:  74474 Min:     23 Act:  235 Avg:   77 Max:    8278
T: 1 (  531) P:99 I:1500 C:  49482 Min:     24 Act:   32 Avg:   56 Max:    8277
T: 2 (  532) P:99 I:2000 C:  36805 Min:     24 Act:   38 Avg:   79 Max:    8170
T: 3 (  533) P:99 I:2500 C:  29333 Min:     25 Act:   41 Avg:   54 Max:    7069
T: 4 (  534) P:99 I:3000 C:  24344 Min:     24 Act:   51 Avg:   60 Max:    7193

//Cobalt on 6ULL with stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 128M --metrics-brief
policy: fifo: loadavg: 7.02 6.50 4.01 8/100 660

T: 0 (  652) P:50 I:1000 C: 560348 Min:      1 Act:   10 Avg:   15 Max:      71
T: 1 (  653) P:50 I:1500 C: 373556 Min:      1 Act:    9 Avg:   17 Max:      78
T: 2 (  654) P:50 I:2000 C: 280157 Min:      2 Act:   14 Avg:   20 Max:      64
T: 3 (  655) P:50 I:2500 C: 224120 Min:      1 Act:   12 Avg:   15 Max:      57
T: 4 (  656) P:50 I:3000 C: 186765 Min:      1 Act:   31 Avg:   19 Max:      53

//Cobalt on 6qp with stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 512M --metrics-brief
policy: fifo: loadavg: 8.11 7.44 4.45 8/156 1057
T: 0 (  917) P:50 I:1000 C: 686106 Min:      0 Act:    3 Avg:    5 Max:      53
T: 1 (  918) P:50 I:1500 C: 457395 Min:      0 Act:    3 Avg:    5 Max:      49
T: 2 (  919) P:50 I:2000 C: 342866 Min:      0 Act:    2 Avg:    4 Max:      43
T: 3 (  920) P:50 I:2500 C: 274425 Min:      0 Act:    3 Avg:    5 Max:      58
T: 4 (  921) P:50 I:3000 C: 228682 Min:      0 Act:    2 Avg:    6 Max:      46

//Cobalt on 6dl with stress-ng --cpu 2 --io 2 --vm 1 --vm-bytes 256M --metrics-brief
policy: fifo: loadavg: 3.35 4.15 2.47 1/122 850
T: 0 (  729) P:50 I:1000 C: 608088 Min:      0 Act:    1 Avg:    3 Max:      34
T: 1 (  730) P:50 I:1500 C: 405389 Min:      0 Act:    0 Avg:    4 Max:      38
T: 2 (  731) P:50 I:2000 C: 304039 Min:      0 Act:    1 Avg:    4 Max:      45
T: 3 (  732) P:50 I:2500 C: 243225 Min:      0 Act:    0 Avg:    4 Max:      49
T: 4 (  733) P:50 I:3000 C: 202683 Min:      0 Act:    0 Avg:    5 Max:      38

//Cobalt on 6SX stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 512M  --metrics-brief
policy: fifo: loadavg: 7.51 7.19 6.66 8/123 670
T: 0 (  598) P:50 I:1000 C:2314339 Min:      0 Act:    3 Avg:    8 Max:      60
T: 1 (  599) P:50 I:1500 C:1542873 Min:      0 Act:   15 Avg:    8 Max:      72
T: 2 (  600) P:50 I:2000 C:1157152 Min:      0 Act:    4 Avg:    9 Max:      55
T: 3 (  601) P:50 I:2500 C: 925721 Min:      0 Act:    5 Avg:    9 Max:      57
T: 4 (  602) P:50 I:3000 C: 771434 Min:      0 Act:    6 Avg:    6 Max:      41

//Cobalt on 6Solo lite stress-ng --cpu 4 --io 2 --vm 1 --vm-bytes 512M  --metrics-brief
policy: fifo: loadavg: 7.01 7.04 6.93 8/104 598
T: 0 (  571) P:50 I:1000 C:3639967 Min:      0 Act:    9 Avg:    7 Max:      60
T: 1 (  572) P:50 I:1500 C:2426642 Min:      0 Act:    9 Avg:   11 Max:      66
T: 2 (  573) P:50 I:2000 C:1819980 Min:      0 Act:   11 Avg:   10 Max:      57
T: 3 (  574) P:50 I:2500 C:1455983 Min:      0 Act:   12 Avg:   10 Max:      56
T: 4 (  575) P:50 I:3000 C:1213316 Min:      0 Act:    7 Avg:    9 Max:      43

//Cobalt on 7d with stress-ng --cpu 2 --io 2 --vm 1 --vm-bytes 256M --metrics-brief

policy: fifo: loadavg: 5.03 5.11 5.15 6/107 683
T: 0 (  626) P:50 I:1000 C:6842938 Min:      0 Act:    1 Avg:    2 Max:      63
T: 1 (  627) P:50 I:1500 C:4561953 Min:      0 Act:    4 Avg:    2 Max:      66
T: 2 (  628) P:50 I:2000 C:3421461 Min:      0 Act:    0 Avg:    2 Max:      69
T: 3 (  629) P:50 I:2500 C:2737166 Min:      0 Act:    3 Avg:    2 Max:      71
T: 4 (  630) P:50 I:3000 C:2280969 Min:      0 Act:    2 Avg:    1 Max:      33

//////////////////////////////////////// Update for Yocto L5.10.52 2.1.0  ///////////////////////////////////////////////////////////

New release for Yocto release L5.10.52 2.1.0. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm and git checkout xenomai-5.10.52-2.1.0.

Updating:

1, Upgrade Xenomai to v3.2

2, Enable Dovetail instead of ipipe.

Copy xenomai-arm to <Yocto folder>/sources/meta-imx/meta-bsp/recipes-kernel, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitake imx-image-multimedia.

XENOMAI_KERNEL_MODE = "cobalt"

IMAGE_INSTALL_append += " xenomai"

or

XENOMAI_KERNEL_MODE = "mercury"

IMAGE_INSTALL_append += " xenomai"

Notice: If XENOMAI_KERNEL_MODE = "cobalt", you can build dual kernel version. And If XENOMAI_KERNEL_MODE = "mercury", it is single kernel with PREEMPT-RT patch.

//////////////////////////////////////// Update for Yocto L5.15.71 2.2.0  ///////////////////////////////////////////////////////////

New release for Yocto release L5.15.71 2.2.0. You need to git clone https://gitee.com/zxd2021-imx/xenomai-arm and git checkout xenomai-5.15.71-2.2.0.

Updating:

1, Upgrade Xenomai to v3.2.2

Copy xenomai-arm to <Yocto folder>/sources/meta-imx/meta-bsp/recipes-kernel, and add the following variable in conf/local.conf before build Image with xenomai enable by command bitake imx-image-multimedia.

XENOMAI_KERNEL_MODE = "cobalt"

IMAGE_INSTALL:append += " xenomai"

or

XENOMAI_KERNEL_MODE = "mercury"

IMAGE_INSTALL:append += " xenomai"

Notice: If XENOMAI_KERNEL_MODE = "cobalt", you can build dual kernel version. And If XENOMAI_KERNEL_MODE = "mercury", it is single kernel with PREEMPT-RT patch.

///////// Later update for Later Yocto release, please refer to the following community post ////////////

移植实时Linux方案Xenomai到i.MX ARM64平台 (Enable real-time Linux Xenomai on i.MX ARM64 Platform)