SAMA7D65 Source Overview

For the SAMA7D65 board, it is necessary to modify various support files within the kernel to use the maXTouch Linux Driver.

Although the main Linux4SAM kernel repository (Linux & Open Source for AT91 Microchip Microprocessors) Github site has a working maXTouch Linux Driver, it does not contained the many added features to support newer maXTouch chips along with the additional debug features available when using the mxt-app utility.

For the touchscreen development, a prebulit demo image is used for testing with the various components and links noted below:

SAMA7D65 Curiosity Board Demo Images

The demo image contains the following components:

• Kernel image embedded with device tree overlay data in a .itb format

  Tag: main Link: maXTouch Linux 6.12 Kernel

• U-boot and U-boot environment configuration file in a .bin format and .txt source file

  Tag: linux4microchip+sama7d65-2025.02

• Bootstrap binary file used as a 2nd level bootloader for the Microchip microprocessors

  Tag: 4.0.11 Link: AT91Bootstrap 4.0.11

• Rootfs filesystem files
• Yocto Project / Poky based image file in a .ubi format

  Poky Demo Board Image Source Link: Linux4SAM Developer Help

Modified versions of the kernel support files are located in the maXTouch_linux_6.12 Github website. The maXTouch Linux driver within the kernel and the u-boot-env.bin file are the main components being modified during this development. The other components of the demo image will not be used.

The following sections within this Wiki describe the modifications to the driver and associated support files.

1. Device Tree Files Overlays
2. Configuring the Kernel Options
3. Building the Kernel Source
4. Modifying the U-boot-env.txt File
5. Loading the Touch Driver