Linux Kernel - 6.12

Linux 6.12 for MPU source code

The Linux kernel for Microchip ARM-Based MPUs (aka AT91) is distributed as a GIT tree hosted on GitHub as a fork of the official Linus Torvalds' git tree. The objective of the Microchip Linux team is to integrate all the AT91-related material in the official Linux Kernel.
Before completing this inclusion process, which can take time, this website provides the Linux4SAM Linux Kernel git tree for AT91 devices at:

https://github.com/linux4microchip/linux/tree/linux-6.12-mchp

Tags

linux4microchip-2025.04 tag

Enhancements are added on top of the official v6.12 Linux kernel tag where most of the Microchip SoC features are already supported. Note as well that we re-integrate each and every stable kernel release on top of this Long Term Support (LTS) kernel revision. This means that each v6.12.x version is merged in our branch.

Here is a little summary of the main additional enhancements:

• Integration of stable Long Term Support (LTS) kernel updates up to v6.12.22
• Improve support for SAMA7D65 Curiosity board.
• Add initial support for SAMA7G54 SoM and SAM9x75 SoM
• Add support for unified WILC S02 FW 3.1 and WILC 1000/3000 FW 16.4 WiFi / BLE driver.
• Add initial support for GFX2D GPU
• Add support for ASRC peripheral to peripheral for SAMA7G65
• Enable WM8731 audio codec as a module.
• Add shutdown controller support for SAM9X7 SoC.
• Improve SoC driver with support for SAMA7D65.
• Crypto: add fallback for unsupported ESP header length (not multiple of 4 words).
• Clock: configure ACR register in all PLL settings. Update clock API usage for SAMA7G5 and SAMA7D65.
• OP-TEE: Update SCMI for SAMA7G5 to include GCLK for PDMC0 and PDMC1.
• QSPI: add support for SAMA7D65
• Added support for PAC194X and PAC195X Current and Power Monitors
• Added support for LAN9646 and updated support for LAN937X, KSZ9896, KSZ9477 gigabit Ethernet switches

Required packages

You must install essential host packages on your build host. These requirements are listed in the Linux kernel documentation with the chapter Install build requirements. You must follow this process which includes, but not limited to, the following packages:

• build-essential
• flex
• bison
• git
• perl-base
• libssl-dev
• libncurses5-dev
• libncursesw5-dev
• ncurses-dev

Getting Kernel sources

To get the source code, you have to clone the repository:

The source code has been taken from the master branch which is pointing on the latest branch we use.

If you want to use another branch, you can list them and use one of them by doing this:

Setup ARM Cross Compiler

• First step is to dowload the ARM GNU Toolchain:

  wget -c https://developer.arm.com/-/media/Files/downloads/gnu/13.2.rel1/binrel/arm-gnu-toolchain-13.2.rel1-x86_64-arm-none-linux-gnueabihf.tar.xz 

• Next step is to add the ARM GNU Toolchain into your system:

  tar -xf arm-gnu-toolchain-13.2.rel1-x86_64-arm-none-linux-gnueabihf.tar.xz
  export CROSS_COMPILE=`pwd`/arm-gnu-toolchain-13.2.rel1-x86_64-arm-none-linux-gnueabihf/bin/arm-none-linux-gnueabihf-

  or

  tar -xf arm-gnu-toolchain-13.2.rel1-x86_64-arm-none-linux-gnueabihf.tar.xz
  export CROSS_COMPILE=arm-none-linux-gnueabihf-
  export PATH=$PATH:/YOUR/PATH/TO/arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-linux-gnueabihf/bin/

  • Information

     If you already have an old ARM GNU Toolchain need to clean up the PATH with:

    export PATH=${PATH/':/YOUR/PATH/TO/arm-gnu-toolchain-VERSION-x86_64-arm-none-linux-gnueabihf/bin/'/}
        

  Configure and Build the Linux kernel

  Now you have to configure the Linux kernel according to your hardware. We have two default configuration at91 SoC in arch/arm/configs

  arch/arm/configs/at91_dt_defconfig
  arch/arm/configs/sama5_defconfig
  arch/arm/configs/sama7_defconfig

  • at91_dt_defconfig: for SAM9 (ARM926) series chips
  • sama5_defconfig: for SAMA5 series chips
  • sama7_defconfig: for SAMA7 series chips

  Now we Configure and Build kernel for board:

  $ make ARCH=arm sama5_defconfig
    HOSTCC  scripts/basic/fixdep
    HOSTCC  scripts/kconfig/conf.o
    SHIPPED scripts/kconfig/zconf.tab.c
    SHIPPED scripts/kconfig/zconf.lex.c
    SHIPPED scripts/kconfig/zconf.hash.c
    HOSTCC  scripts/kconfig/zconf.tab.o
    HOSTLD  scripts/kconfig/conf
  #
  # configuration written to .config
  #
  

  At this step, you can modify default configuration using the menuconfig

  $ make ARCH=arm menuconfig

  Now, in the menuconfig dialog, you can easily add or remove some features. Once done, Move to <Exit> with arrows and press this button hitting the Enter key to exit from this screen.

  Build the Linux kernel image, before you build you need set up the cross compile toolchain, check this section.

  $ make ARCH=arm
  
  [..]
  
    Kernel: arch/arm/boot/Image is ready
    Kernel: arch/arm/boot/zImage is ready

  Now you have an usable compressed kernel image zImage.

  If you need an uImage you can run this additional step:

  make ARCH=arm uImage LOADADDR=0x20008000
  
  [..]
  
  Kernel: arch/arm/boot/Image is ready
  Kernel: arch/arm/boot/zImage is ready
  UIMAGE  arch/arm/boot/uImage
  Image Name:   Linux-6.12.22-linux4microchip-20
  Created:      Thu May 22 18:05:21 2025
  Image Type:   ARM Linux Kernel Image (uncompressed)
  Data Size:    5688984 Bytes = 5555.65 KiB = 5.43 MiB
  Load Address: 20008000
  Entry Point:  20008000
  Kernel: arch/arm/boot/uImage is ready
  

  make ARCH=arm dtbs
  
  [..]
  
    DTC     arch/arm/boot/dts/microchip/at91-sama5d27_som1_ek.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama5d29_curiosity.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama5d2_icp.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama5d3_eds.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama7d65_curiosity.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama7g54_curiosity.dtb
    DTC     arch/arm/boot/dts/microchip/at91-sama7g5ek.dtb
  
  [..]

  If the building process is successful, the final images can be found under arch/arm/boot/ directory.

  Related Topics