Linux Kernel - 6.1

Linux 6.1 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:


linux4microchip-2023.04 tag

Enhancements are added on top of the official v6.1 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 v6.1.x version is merged in our branch.

Here is a little summary of the main additional enhancements:

  • Integration of stable kernel updates up to v6.1.22
  • Runtime PM support for at_xdmac DMA driver
  • System suspend/resume for at_xdmac DMA driver
  • Fixes for at_xdmac DMA driver to avoid failure on DMA channels on system suspend/resume
  • Runtime PM support for Microchip SPDIFTX driver
  • System suspend/resume support for Microchip SPDIFTX driver
  • Cleanups and improvements for Microchip SPDIFTX driver
  • Runtime PM support for Microchip PDMC driver
  • System suspend/resume support for Microchip PDMC driver
  • Fix poc noises when starting capture for Microchip PDMC driver
  • Runtime PM support for Microchip SPDIFRX driver
  • System suspend/resume support for Microchip SPDIFRX driver
  • Fix controls for Microchip SPDIFRX driver to avoid concurrency on hardware resources
  • Cleanups and improvements for Microchip SPDIFRX driver
  • Removed atmel-sdramc driver and handle the clocks on proper clock drivers
  • Fix imbalanced reference counter on Ethernet device that made ULP modes to fail
  • Runtime PM support on SPI driver
  • Delay timer support on Microchip PIT64B driver
  • Cleanups on pinctrl driver to avoid potential leaks and simplify code
  • Support for line bias flags that have been implemented in gpio API for at91 pio4 pinctrl driver
  • Support for push-pull configuration in at91 pio4 pinctrl driver
  • Zero length message digest support for hmac in atmel-sha driver
  • Detection of in-place operations with two sg lists in atmel-tdes and atmel-aes drivers
  • Match cfb block size with generic implementation in atmel-aes driver
  • Microchip ISC/XISC mainline compatible drivers
  • Enable PAC1934 support on SAMA7G5-EK, SAMA5D2-ICP, SAM9X60-EK boards
  • Fix PTP TX timestamp handling due to padding and improve PTP TX timestamp on MACB driver
  • Enable PTP support on SAMA7G5
  • Enable SAMA7G54 SiPs

Getting Kernel sources

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

$ git clone
Cloning into 'linux'...
remote: Enumerating objects: 8587836, done.
remote: Total 8587836 (delta 0), reused 0 (delta 0), pack-reused 8587836
Receiving objects: 100% (8587836/8587836), 3.49 GiB | 13.44 MiB/s, done.
Resolving deltas: 100% (7117887/7117887), done.
Updating files: 100% (70687/70687), done.
$ cd linux

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

Pointing hand Note that you can also add this Linux4SAM repository as a remote GIT repository to your usual Linux git tree. It will save you a lot of bandwidth and download time:

$ git remote add linux4microchip
$ git remote update linux4microchip
Fetching linux4icrochip
 * [new branch]                linux-5.10-mchp -> linux4microchip/linux-5.10-mchp
 * [new branch]                linux-5.15-mchp -> linux4microchip/linux-5.15-mchp
 * [new branch]                linux-6.1-mchp -> linux4microchip/linux-6.1-mchp
 * [new branch]                master     -> linux4microchip/master

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

$ git branch -r
  origin/HEAD -> origin/master
$ git checkout origin/linux-6.1-mchp -b linux-6.1-mchp
Branch linux-6.1-mchp set up to track remote branch linux-6.1-mchp from origin.
Switched to a new branch 'linux-6.1-mchp'

Setup ARM Cross Compiler

Ubuntu: In Ubuntu, you can install the ARM Cross Compiler by doing:

sudo apt-get install gcc-arm-linux-gnueabi
export CROSS_COMPILE=arm-linux-gnueabi-

Others: For others, you can download the ARM cross compiler and setup the environment by doing:

wget -c
tar xf gcc-arm-10.2-2020.11-x86_64-arm-none-linux-gnueabihf.tar.xz
export CROSS_COMPILE=`pwd`/gcc-arm-10.2-2020.11-x86_64-arm-none-linux-gnueabihf/bin/arm-none-linux-gnueabihf-

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

  • 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/
  SHIPPED scripts/kconfig/zconf.lex.c
  SHIPPED scripts/kconfig/zconf.hash.c
  HOSTCC  scripts/kconfig/
  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/zImage is ready
  UIMAGE  arch/arm/boot/uImage
Image Name:   Linux-6.1.22-linux4microchip-20
Created:      Wed May  4 21:18:58 2022
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:    5069704 Bytes = 4950.88 KiB = 4.83 MiB
Load Address: 20008000
Entry Point:  20008000
  Kernel: arch/arm/boot/uImage is ready

make ARCH=arm dtbs


  DTC     arch/arm/boot/dts/at91-kizbox2-2.dtb
  DTC     arch/arm/boot/dts/at91-kizbox3-hs.dtb
  DTC     arch/arm/boot/dts/at91-nattis-2-natte-2.dtb
  DTC     arch/arm/boot/dts/at91-sama5d27_som1_ek.dtb
  DTC     arch/arm/boot/dts/at91-sama5d27_wlsom1_ek.dtb
  DTC     arch/arm/boot/dts/at91-sama5d2_icp.dtb
  DTC     arch/arm/boot/dts/at91-sama5d2_ptc_ek.dtb
  DTC     arch/arm/boot/dts/at91-sama5d2_xplained.dtb
  DTC     arch/arm/boot/dts/at91-sama5d3_xplained.dtb
  DTC     arch/arm/boot/dts/at91-dvk_som60.dtb
  DTC     arch/arm/boot/dts/at91-gatwick.dtb
  DTC     arch/arm/boot/dts/at91-tse850-3.dtb
  DTC     arch/arm/boot/dts/at91-wb50n.dtb
  DTC     arch/arm/boot/dts/sama5d31ek.dtb
  DTC     arch/arm/boot/dts/sama5d33ek.dtb
  DTC     arch/arm/boot/dts/sama5d34ek.dtb
  DTC     arch/arm/boot/dts/sama5d35ek.dtb
  DTC     arch/arm/boot/dts/sama5d36ek.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_cmp.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4_ma5d4evk.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4_xplained.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4ek.dtb
  DTC     arch/arm/boot/dts/at91-vinco.dtb
  DTC     arch/arm/boot/dts/at91-sama7g5ek.dtb
  DTC     arch/arm/boot/dts/at91-sam9x60_curiosity.dtb


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

Recent FAQ


Using SAMA 5 D 2 ADCDevice: Using the SAMA5D2-compatible ADC device. (Sam9x60Curiosity, Sama7g5-ek, Sama5d2-icp, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained)
Sama 7 g 5 Ov 7740: Interfacing sama7g5 with parallel omnivision ov7740 sensor.. (Sama7g5-ek)
Sama 7 g 5 Xisc: Detailed explanation of the sama7g5 image acquisition pipeline. (Sama7g5-ek)
Using ASRC: How to use ASRC. (Sama7g5-ek)
Thermal Faq: Thermal management support on SAMA7G5. (Sama7g5-ek)
Using Isi 6: Using ISI with Linux4sam 6.0 and Kernel 4.14 and later. (Sam9x60EK, Sama5d3xek, AT91sam9x5-ek)
Boot Logo: Boot Logo for At91 SOC's. (Sama5d2Xplained)
Sam 9 x 60 Ek Attaching Tm 5000 Display: Addition to the other generic FAQ about LCD displays: ConnectModuleFromPDA. (Sam9x60EK)
Using SAMA 5 D 2 Resistive Touchscreen: Guide for SAMA5D2 Resistive Touchscreen. (Sama5d2Xplained)
Iio Adc Driver: Adc IIO driver introduction. (Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek, AT91sam9x5-ek, other AT91SAM9 boards)
SOM 1 EKe MMCSupport: . (Sama5d27Som1EK)
Using PTC: How to use PTC. (Sama5d27WLSom1EK, Sama5d2PtcEK)
Crypto Config: How to configure Crypto driver. (Sam9x60Curiosity, Sama5d2-icp, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek)
USBGadget Config: Configure AT91 USB Gadget on Linux and Endpoint order management (composite USB). (Sam9x60Curiosity, Sama5d2-icp, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek, AT91sam9x5-ek, other AT91SAM9 boards)
Pwm Faq: PWM Driver. (Sam9x60Curiosity, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d3Xplained, Sama5d3xek)
Using Atmel DRMDriver: Using Atmel KMS/DRM LCD driver. (Sam9x60Curiosity, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek)
r5 - 23 May 2023 - 14:48:31 - CristianBirsan
Linux & Open Source for AT91 Microchip Microprocessors

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