----------------------------------------------------- = Gumstix Geppetto Pepper (AM335x) designs = = AutoBSP README file = = Copyright (c) 2017, Gumstix, Inc. = ----------------------------------------------------- Introduction ------------ The TI Sitara AM335x SoC module included in your Geppetto design is the chip used on the Gumstix Pepper SBCs. Gumstix provides a custom Yocto Linux disk image for use with these devices. In order to take full advantage of the hardware embedded in your design, The Pepper's bootloader uses a device tree blob, a DTB, to facilitate communication between the operating system and the expansion board's hardware. AutoBSP delivers a custom DTB for Geppetto Pepper designs, incorporating the device tree features required by the kernel and many device drivers. Instructions for the compilation, installation and use of the device tree file, and a list of helpful links, are provided in this document. Links ----- - Gumstix getting started guide: https://www.gumstix.com/support/getting-started/ - Gumstix Pepper disk image files: - MLO: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/MLO - zImage: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/zImage - uboot.img: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/u-boot.img - Kernel modules and drivers: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/modules-pepper.tgz - Gumstix Pepper Yocto Console rootfs: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/gumstix-console-image-pepper.tar.bz2 - Gumstix Pepper Yocto XFCE rootfs: https://gumstix-yocto.s3.amazonaws.com/2018-05-12/pepper/morty/gumstix-xfce-image-pepper.tar.bz2 Folder Contents --------------- - devicetree-pepper.dtb Compiled device tree blob - devicetree-pepper.dts Device tree source - README.txt This file Installation Instructions ------------------------- 1. Download the disk image files from the link listed above and create a microSD card following the getting started instructions on the Gumstix website 2. Copy the DTB file designed for your SBC into the boot folder of the card's root file system $ sudo cp devicetree-pepper.dtb /media/$USER/rootfs/boot 3. Create a file on the SD card's boot partition called uEnv.txt containing the following string: 'fdtfile=devicetree-pepper.dtb' $ echo "fdtfile=devicetree-pepper.dtb" > /media/$USER/boot/uEnv.txt 4. Insert the microSD card into the SBC's card reader and connect the board to a power supply Compilation Instructions ------------------------ 1. Install the required software and clone the Gumstix Linux kernel repository $ sudo apt install gcc-arm-linux-gnueabi build-essential git dtc $ git clone https://github.com/gumstix/linux.git -b yocto-v4.8.y 2. Prepare the build environment $ cd /linux $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- omap2plus_defconfig dtbs 3. Copy the DTS file you wish to compile within the kernel's device tree source directory $ cp /devicetree-pepper.dts /linux/arch/arm/boot/dts/ 4. Build the DTB $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- devicetree-pepper.dtb 5. The compiled device tree will be located in 'arch/arm/boot/dts/'