Linux Kernel - 3.18

Linux 3.18 for AT91 source code

The Linux kernel for Atmel ARM-based SoC (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 Atmel 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-3.18-at91

Changes

  • Update atmel hlcdc driver to DRM driver.
  • Totally support devicetree. Remove the temperory code which not support devicetree.

2015.05

  • pioD is enabled in SAMA5D4, also add usart1, usart2 for SAMA5D4.
  • DRM driver fixes.

Tags

linux4sam_5.0-alpha7 tag

  • support for new SAMA5D2 SoC and the associated sama5d2 Xplained board
    • QSPI with DMA (disabled in Device Tree by default)
    • Flexcom with FIFO & DMA
      • USART interface
      • I2C interface
      • SPI interface
    • SD/MMC interface (SDHCI) + on-board eMMC
    • Audio using Class D amplifier
    • ISC
      • support YUV sensor output
      • support RGB output format
    • Crypto engines
      • AEAD support for IPSec
  • fix residue computation for HDMA
  • ISI: add RGB565, GREY, SGRBG, SBGGR (Bayer) support
  • runtime PM: added the ISI driver, modifications to the HLCD DRM driver

And the enhancements from linux4sam_4.7 tag below

linux4sam_4.7 tag

  • Based on 3.18 linux kernel
  • Update atmel hlcdc driver to DRM driver.
  • Totally support devicetree. Remove the temperory code which not support devicetree.
  • SAMA5 series boards support
  • HDMI driver for SiI902x component on SAMA5D4-EK and SAMA5D4 Xplained boards
  • add LCD driver entries in at91sam9x5 and at91sam9n12 DT (HLCD DRM driver)
  • Power management enhancements
  • Power management states on pin configuration (pinctrl OUTPUT configuration)
  • Power management pin states for: SPI, i2c, MMC, serial, LCD, SSC, IIO (ADC), ETH, NAND, CAN
  • Serial RX & TX DMA support
  • Serial fixes and enhancements
  • updated clock management for USB (OHCI and EHCI)

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: Counting objects: 5239592, done.
remote: Compressing objects: 100% (764014/764014), done.
Receiving objects: 100% (5239592/5239592), 1018.56 MiB | 11.18 MiB/s, done.
remote: Total 5239592 (delta 4448248), reused 5218219 (delta 4427054)
Resolving deltas: 100% (4448248/4448248), done.
Checking out files: 100% (38567/38567), done.

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]                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/master
$ git checkout origin/linux-3.18-at91 -b linux-3.18-at91
Branch linux-3.18-at91 set up to track remote branch linux-3.18-at91 from origin.
Switched to a new branch 'linux-3.18-at91'

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 Linaro cross compiler and setup the environment by doing: 
    wget -c https://releases.linaro.org/components/toolchain/binaries/4.9-2017.01/arm-linux-gnueabi/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabi.tar.xz
tar xf gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabi.tar.xz
export CROSS_COMPILE=`pwd`/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabi/bin/arm-linux-gnueabi-

Configuration files for boards

3.18 (linux4sam_5.0-alpha7 tag)
Board Description Binary Device Tree Binary (DTB) Configuration file
sama5d2_xplained linux-3.18-at91 zImage zImage-sama5.bin at91-sama5d2_xplained.dtb
at91-sama5d2_xplained_pda4.dtb 		sama5d2_defconfig
3.18 (linux4sam_4.7 tag)
Board Description Binary Device Tree Binary (DTB) Configuration file
sama5d3xek linux-3.18-at91 zImage zImage-sama5.bin sama5d31ek.dtb
sama5d33ek.dtb
sama5d34ek.dtb
sama5d35ek.dtb
sama5d36ek.dtb
sama5_defconfig
sama5d3_xplained at91-sama5d3_xplained.dtb
sama5d4ek at91-sama5d4ek.dtb
sama5d4_xplained at91-sama5d4_xplained.dtb
at91sam9x5ek zImage-at91sam9.bin at91sam9g15ek.dtb
at91sam9g25ek.dtb
at91sam9g35ek.dtb
at91sam9x25ek.dtb
at91sam9x35ek.dtb 		at91_dt_defconfig
at91sam9n12ek at91sam9n12ek.dtb
at91sam9m10g45ek at91sam9m10g45ek.dtb

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/sama5d2_defconfig

  • at91_dt_defconfig: for at91sam ARM926 series chips
  • sama5_defconfig: for SAMA5 series chips
  • sama5d2_defconfig: for SAMA5D2 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

And 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

[..]

  OBJCOPY arch/arm/boot/zImage
  Kernel: arch/arm/boot/zImage is ready
  UIMAGE  arch/arm/boot/uImage
Image Name:   Linux-3.18.0-00020-g03329ca
Created:      Wed May  6 15:44:56 2015
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:    3537576 Bytes = 3454.66 kB = 3.37 MB
Load Address: 20008000
Entry Point:  20008000
  Image arch/arm/boot/uImage is ready



make ARCH=arm dtbs

[..]

  DTC     arch/arm/boot/dts/at91sam9261ek.dtb
  DTC     arch/arm/boot/dts/at91sam9263ek.dtb
  DTC     arch/arm/boot/dts/at91sam9g20ek.dtb
  DTC     arch/arm/boot/dts/at91sam9g20ek_2mmc.dtb
  DTC     arch/arm/boot/dts/at91sam9m10g45ek.dtb
  DTC     arch/arm/boot/dts/at91sam9n12ek.dtb
  DTC     arch/arm/boot/dts/at91sam9rlek.dtb
  DTC     arch/arm/boot/dts/at91sam9g15ek.dtb
  DTC     arch/arm/boot/dts/at91sam9g25ek.dtb
  DTC     arch/arm/boot/dts/at91sam9g35ek.dtb
  DTC     arch/arm/boot/dts/at91sam9x25ek.dtb
  DTC     arch/arm/boot/dts/at91sam9x35ek.dtb
  DTC     arch/arm/boot/dts/at91-sama5d3_xplained.dtb
  DTC     arch/arm/boot/dts/at91-sama5d3_xplained_pda4.dtb
  DTC     arch/arm/boot/dts/at91-sama5d3_xplained_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d31ek.dtb
  DTC     arch/arm/boot/dts/sama5d31ek_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d31ek_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d31ek_revc.dtb
  DTC     arch/arm/boot/dts/sama5d31ek_revc_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d31ek_revc_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d33ek.dtb
  DTC     arch/arm/boot/dts/sama5d33ek_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d33ek_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d33ek_revc.dtb
  DTC     arch/arm/boot/dts/sama5d33ek_revc_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d33ek_revc_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d34ek.dtb
  DTC     arch/arm/boot/dts/sama5d34ek_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d34ek_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d34ek_revc.dtb
  DTC     arch/arm/boot/dts/sama5d34ek_revc_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d34ek_revc_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d35ek.dtb
  DTC     arch/arm/boot/dts/sama5d35ek_revc.dtb
  DTC     arch/arm/boot/dts/sama5d36ek.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_pda7.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_revc.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_revc_pda4.dtb
  DTC     arch/arm/boot/dts/sama5d36ek_revc_pda7.dtb
  DTC     arch/arm/boot/dts/at91-sama5d2_xplained.dtb
  DTC     arch/arm/boot/dts/at91-sama5d2_xplained_pda4.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4_xplained.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4_xplained_hdmi.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4_xplained_pda4.dtb
  DTC     arch/arm/boot/dts/at91-sama5d4ek.dtb

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

Recent FAQ

linux-3.18-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)
• Pwm Faq: PWM Driver. (Sama5d29Curiosity, Sam9x75Curiosity, Sam9x60Curiosity, Sam9x60EK, Sama5d27WLSom1EK, Sama5d27Som1EK, Sama5d2PtcEK, Sama5d2Xplained, Sama5d4Xplained, Sama5d3Xplained, Sama5d3xek)
• Iio Adc Driver: Adc IIO driver introduction. (Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek, AT91sam9x5-ek, other AT91SAM9 boards)
• Using Isi: How to use the Image Sensor Interface. (Sama5d4Xplained, Sama5d4ek, Sama5d3Xplained, Sama5d3xek)