Edge-V：如何将内核打上实时补丁？ How to add RT patches？

liuliyuan · March 1, 2022, 11:56am

自动配置和推荐的内核分支是khadas-edge-4.4.y，其中Makefile显示版本是4.4.194，这个版本在https://wiki.linuxfoundation.org/realtime/start 是没有匹配的，也就是无法安装上实时补丁。

想请问有什么思路能让Edge-V打上实时补丁，或者直接更新实时内核？

The auto-configured and recommended kernel branch is khadas-edge-4.4.y, where the Makefile shows that the version is 4.4.194, this version does not match realtime:start [Wiki], that is, it cannot be installed real-time patching.

I would like to ask if there are any ideas to make Edge-V patched in real time, or update the real-time kernel directly?

Frank · March 2, 2022, 12:37am

@liuliyuan 实时补丁是啥意思？主线的补丁么？

如果你是指主线的内核，你可以编译一个主线固件，目前是5.16的内核

liuliyuan · March 2, 2022, 2:18am

你好，frank，我在khadas官方git上没有找到相应的5.16内核版本(https://github.com/khadas/linux/branches/all)，

Edge-V主芯片时RK3399的，我的目的是想在Edge-V的板子上使用可以安装实时补丁( PREEMPT_RT patches)的内核版本，但我看官方git上没有找到Edge可以安装实时补丁的内核版本。

Frank · March 2, 2022, 2:21am

@liuliyuan 主线的固件是另外一种编译方法。我们会直接拉取从linux主线拉取对应版本的源码。然后打上基础补丁，编译出固件。

这也意味着很多4.4版本上的功能可能在主线是没有的。

liuliyuan · March 2, 2022, 2:37am

感谢回答，但是我如何能确定我在manline上选择的是哪一份内核版本，似乎从操作上并没有提示，或者可以指定对应版本？（第一次接触khadas的板子，疑问较多，请谅解）。

Choose Khadas board:

Edge - Khadas Edge with Rockchip RK3399 SoC
VIM1 - Khadas VIM1 with Amlogic S905X SoC
VIM2 - Khadas VIM2 with Amlogic S912 SoC
VIM3 - Khadas VIM3 with Amlogic A311D SoC
VIM3L - Khadas VIM3L with Amlogic S905D3 SoC
Generic - Generic image (VIM1 VIM2 VIM3 VIM3L Edge) EXPERIMENTAL

Which board would you like? [2] 1
=> Edge

Choose uboot version:

uboot-2017.09 - U-boot 2017.09
uboot-mainline - U-boot Mainline

Which uboot version would you like? [1] 2
=> mainline

Choose linux version:

linux-mainline

only one choose => mainline

Choose distribution:

Ubuntu - Ubuntu
Debian - Debian

Which distribution would you like? [1] 1
=> Ubuntu

Choose Ubuntu release:

bionic - Ubuntu 18.04
focal - Ubuntu 20.04

Which Ubuntu release would you like? [2] 2
=> focal

Choose Ubuntu type:

server - Headless Image With Essential Packages
minimal - Minimal Image With Very Basic Packages
xfce - Desktop Image With XFCE Desktop
lxde - Desktop Image With LXDE Desktop
gnome - Desktop Image With GNOME Desktop

Which Ubuntu type would you like? [1] 5
=> gnome

Set architecture to ‘arm64’ by default.
=> arm64

Choose install type:
only one choose => SD-USB

Compress image? [N|y] y

=> yes

== ENV CONFIG =======================
VERSION=1.0.10
KHADAS_BOARD=Edge
LINUX=mainline
UBOOT=mainline
DISTRIBUTION=Ubuntu
DISTRIB_RELEASE=focal
DISTRIB_TYPE=gnome
DISTRIB_ARCH=arm64
INSTALL_TYPE=SD-USB
COMPRESS_IMAGE=yes

== ONE LINE CONFIG ==================
source setenv.sh -q -s KHADAS_BOARD=Edge LINUX=mainline UBOOT=mainline DISTRIBUTION=Ubuntu DISTRIB_RELEASE=focal DISTRIB_TYPE=gnome DISTRIB_ARCH=arm64 INSTALL_TYPE=SD-USB COMPRESS_IMAGE=yes

Environment setup done. Type ‘make’ to build.

Frank · March 2, 2022, 2:41am

@liuliyuan 不是在这里配置的，这里只能指定编译主线固件，指定版本的地方在这里

github.com

khadas/fenix/blob/master/packages/linux-mainline/package.mk#L4

    
      
          PKG_NAME="linux-mainline"
          #PKG_VERSION="5.14"
          #PKG_VERSION="5.15.2"
          PKG_VERSION=${PKG_VERSION:-5.16}
          PKG_VERSION_SHORT="v5.x"
          #PKG_SHA256=
          PKG_SOURCE_DIR="linux-${PKG_VERSION}"
          PKG_SITE="https://cdn.kernel.org/"
          PKG_URL=https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/snapshot/linux-${PKG_VERSION}.tar.gz
          PKG_SOURCE_NAME=linux-${PKG_VERSION}.tar.gz
          PKG_URL=https://cdn.kernel.org/pub/linux/kernel/${PKG_VERSION_SHORT}/${PKG_SOURCE_NAME}
          PKG_URL=https://git.kernel.org/torvalds/t/${PKG_SOURCE_NAME}
          PKG_ARCH="arm aarch64"
          PKG_LICENSE="GPL"

对应的版本的补丁

对应的内核配置

github.com

khadas/fenix/blob/master/packages/linux-mainline/configs/Edge.config

#
# Automatically generated file; DO NOT EDIT.
# Linux/arm64 5.16.0 Kernel Configuration
#
CONFIG_CC_VERSION_TEXT="aarch64-none-linux-gnu-gcc (GNU Toolchain for the A-profile Architecture 9.2-2019.12 (arm-9.10)) 9.2.1 20191025"
CONFIG_CC_IS_GCC=y
CONFIG_GCC_VERSION=90201
CONFIG_CLANG_VERSION=0
CONFIG_AS_IS_GNU=y
CONFIG_AS_VERSION=23301
CONFIG_LD_IS_BFD=y
CONFIG_LD_VERSION=23301
CONFIG_LLD_VERSION=0
CONFIG_CC_CAN_LINK=y
CONFIG_CC_CAN_LINK_STATIC=y
CONFIG_CC_HAS_ASM_GOTO=y
CONFIG_CC_HAS_ASM_INLINE=y
CONFIG_CC_HAS_NO_PROFILE_FN_ATTR=y
CONFIG_IRQ_WORK=y
CONFIG_BUILDTIME_TABLE_SORT=y

This file has been truncated. show original

在这里，你可以看到有好几个版本的补丁。最新的版本就是5.16正式版。所以配置里面默认也是配置的5.16

liuliyuan · March 2, 2022, 2:52am

感谢frank！我先尝试一下，后续有进展给您回复。

另外有一个小小的建议，如果可以的话，希望khadas能新增一些RT的分支，或者提供一些可在fenxi中配置的RT版本。

做运动控制的机器人比较依赖带有RT的内核，后续也许有很多市场机会。

Frank · March 2, 2022, 2:53am

@liuliyuan 感谢你提出的建议，我们会认真考虑这个建议。有任何其他问题欢迎再问。