Linux Kernel - 5.4

Linux 5.4 for AT91 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/linux4sam/linux-at91/tree/linux-5.4-at91

Tags

linux4sam-2020.10 tag

Enhancements are added on top of the official v5.4 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 v5.4.x version is merged in our branch.

Here is a little summary of the main additional enhancements:

  • Integration of stable kernel updates up to v5.4.81
  • Update WILC driver & firmware to 15.4.1
  • QSPI: big performance improvement by using enhanced memory accesses (~ 4 x read speed improvement)
  • ISC / Camera sensor: align with Mainline
  • KSZ8563: Fix number of ports and convert to phylink
  • Sam9x60: support for different System-In-Package (SiP) identifications
  • Sam9x60: align clock sub-system with Mainline and add fractional PLL support
  • Fix CAN message SRAM configuration
  • Sama5d2: Fix securam accesses

linux4sam-2020.04 tag

Enhancements are added on top of the official v5.4 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 v5.4.x version is merged in our branch.

Here is a little summary of the main additional enhancements:

  • Integration of stable kernel updates up to v5.4.41
  • Update WILC driver & firmware to 15.4.
  • Integration of SAMA5D2-ICP board in the release
  • Implement I2C bus recovery mechanism
  • Allow using more than 4 GPIOs as CS in atmel-spi driver
  • Add support for phylink in MACB driver
  • Master clock register offset fixes for SAM9X60 in shutdown, reset controller and PM SoC drivers
  • Improve power saving modes by disabling CPU PLL for SAM9X60
  • Add SAMA5D2-ADC additional software trigger support (for example, sysfs trigger)
  • Add real time timer (RTT) driver for SAM9X60
  • Fix fast drop of VDDCORE on shutdown operations for SAM9X60
  • Refactor reset controller driver
  • Switch the AES and TDES crypto drivers to the skcipher API. Clean the drivers and add various fixes.
  • Mainline SAM9x60 HWRNG support
  • Add support for SHA204A (I2C) random number generator
  • DMA drivers locking improvement and deadlock fixes
  • Fix possible MMIO window size overrun in QSPI driver
  • USB device controller (gadget) driver cleanup & fix for Vbus disconnect DMA issue.
  • Add support for Micron/Aptina MT9V022 monochrome camera sensor for both ISC-based MPUs and ISI-based MPUs.

Getting Kernel sources

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

$ git clone git://github.com/linux4sam/linux-at91.git
Cloning into 'linux-at91'...
remote: Enumerating objects: 50, done.
remote: Counting objects: 100% (50/50), done.
remote: Compressing objects: 100% (44/44), done.
remote: Total 7282027 (delta 24), reused 17 (delta 6), pack-reused 7281977
Receiving objects: 100% (7282027/7282027), 2.09 GiB | 15.93 MiB/s, done.
Resolving deltas: 100% (6114478/6114478), done.
Checking out files: 100% (61813/61813), done.
$ cd linux-at91

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 linux4sam git://github.com/linux4sam/linux-at91.git
$ git remote update linux4sam
Fetching linux4sam
From git://github.com/linux4sam/linux-at91
 * [new branch]                linux-2.6.39-at91 -> linux4sam/linux-2.6.39-at91
 * [new branch]                linux-3.10-at91 -> linux4sam/linux-3.10-at91
 * [new branch]                linux-3.15-at91 -> linux4sam/linux-3.15-at91
 * [new branch]                linux-3.18-at91 -> linux4sam/linux-3.18-at91
 * [new branch]                linux-3.4.9-at91 -> linux4sam/linux-3.4.9-at91
 * [new branch]                linux-3.6.9-at91 -> linux4sam/linux-3.6.9-at91
 * [new branch]                linux-4.1-at91 -> linux4sam/linux-4.1-at91
 * [new branch]                linux-4.4-at91 -> linux4sam/linux-4.4-at91
 * [new branch]                linux-4.9-at91 -> linux4sam/linux-4.9-at91
 * [new branch]                linux-4.14-at91 -> linux4sam/linux-4.14-at91
 * [new branch]                linux-4.19-at91 -> linux4sam/linux-4.19-at91
 * [new branch]                linux-5.4-at91 -> linux4sam/linux-5.4-at91
 * [new branch]                master     -> linux4sam/master

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

$ git branch -r
  origin/HEAD -> origin/master
  origin/linux-2.6.39-at91
  origin/linux-3.10-at91
  origin/linux-3.15-at91
  origin/linux-3.18-at91
  origin/linux-3.4.9-at91
  origin/linux-3.6.9-at91
  origin/linux-4.1-at91
  origin/linux-4.4-at91
  origin/linux-4.9-at91
  origin/linux-4.14-at91
  origin/linux-4.19-at91
  origin/linux-5.4-at91
  origin/master
$ git checkout origin/linux-5.4-at91 -b linux-5.4-at91
Branch linux-5.4-at91 set up to track remote branch linux-5.4-at91 from origin.
Switched to a new branch 'linux-5.4-at91'

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

  • at91_dt_defconfig: for SAM9 (ARM926) series chips
  • sama5_defconfig: for SAMA5 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/zImage is ready
  UIMAGE  arch/arm/boot/uImage
Image Name:   Linux-4.1.0-linux4sam_5.3+
Created:      Fri Sep  9 17:02:45 2016
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:    3441072 Bytes = 3360.42 kB = 3.28 MB
Load Address: 20008000
Entry Point:  20008000
  Image arch/arm/boot/uImage is ready



make ARCH=arm dtbs

[..]
  DTC     arch/arm/boot/dts/at91-kizbox2.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-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-tse850-3.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-sama5d4ek_isi.dtb
  DTC     arch/arm/boot/dts/at91-vinco.dtb
[..]

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

Recent FAQ

linux-5.4-at91

• Using Atmel DRMDriver: Using Atmel KMS/DRM LCD driver. (Sama7d65Curiosity, Sama5d29Curiosity, Sam9x75Curiosity, Sam9x60Curiosity, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek)
• Using Max Touch: Introduction for how to use maxTouch. (Sama5d29Curiosity, Sam9x75Curiosity, Sam9x60Curiosity)
• Crypto Config: How to configure Crypto driver. (Sama5d29Curiosity, Sam9x75Curiosity, 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). (Sama5d29Curiosity, Sam9x75Curiosity, Sam9x60Curiosity, Sama5d2-icp, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek, AT91sam9x5-ek, other AT91SAM9 boards)
• Pwm Faq: PWM Driver. (Sama5d29Curiosity, Sam9x75Curiosity, Sam9x60Curiosity, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d3Xplained, Sama5d3xek)
• ISCWhite Balance Features: White balance features of the Image sensor controller.. (Sam9x75Curiosity, Sama7g5-ek, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2Xplained)
• External Component On EBI: Connecting an external component on the External Bus Interface. (Sam9x75Curiosity, Sam9x60Curiosity, Sam9x60EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek, AT91sam9x5-ek)
• Using Isi 6: Using ISI with Linux4sam 6.0 and Kernel 4.14 and later. (Sam9x60EK, Sama5d3xek, AT91sam9x5-ek)
• 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)
• Using ISC: How to use the Image Sensor Controller. (Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2Xplained)