Many boards in the U-Boot source tree support the 405GP processor. The first step is to see how close we can come to an existing board. Numerous other devices complete the design. The particular board used for this example was provided courtesy of Embedded Planet and came with 64MB of SDRAM and 16MB of on-board Flash.
We will use the Embedded Planet EP405 board, which contains the AMCC Power Architecture 405GP processor. The same logic used in porting to a different CPU applies to porting U-Boot to a new board. Finally, modify the resulting sources to add the specific support for your new CPU's requirements. Determine what CPU is closest to yours, and clone the functionality found in that CPU-specific directory.
U BOOT TUTORIAL PDF CODE
Whether you are porting to a new CPU or a new board based on an existing CPU, study the existing source code for specific guidance. The good news is that someone before you has probably done the bulk of the work. If you must add a new CPU, plan on substantially more effort. If your board contains one of the supported CPUs, porting U-Boot is straightforward. U-Boot supports a large variety of popular CPUs and CPU families in use today, and a much larger collection of reference boards based on these processors. Note that, in some cases, the CPU configuration covers a family of chips, such as ppc4xx, that supports several processors in the Power Architecture 4 xx family. In this same U-Boot version, 49 different CPU configurations are supported (counted in the same manner). board/vendor/boardname subdirectory under the U-Boot top-level source directory, where boardname specifies a particular board.Īs of a recent U-Boot snapshot, more than 460 different board configuration files are named config.mk under the. These files are all given the name config.mk. Each board port must supply a subordinate makefile that supplies board-specific definitions to the build process. One of the reasons U-Boot has become so popular is the ease with which new platforms can be supported. a 0 -e 0 -n Linux -d vmlinux.gz uImageCreate FIT image with compressed PowerPC Linux kernel: mkimage -f s kernel.Embedded Linux Primer: A Practical Real-World Approach, 2nd Edition List image information: mkimage -l uImageCreate legacy image with compressed PowerPC Linux kernel: mkimage -A powerpc -O linux -T kernel -C gzip \\ f s" Image tree source fine that descbres the structure and contents of the FIT image. d Use image data from 'image data file'.Ĭreate FIT image: -D dtc option" Provide special options to the device tree compiler that is used to create the image. Pass -h as the compression to see the list of supported compression type. Pass -h as the image to see the list of supported image type. Pass -h as the OS to see the list of supported OS. bootm command of u-boot changes boot method by os type. Pass -h as the architecture to see the list of supported architectures. List image information: -l mkimage lists the information contained in the header of an existing U-Boot image.Ĭreate old legacy image: -A Set architecture. The new, FIT (Flattened Image Tree) format allows for more flexibility in handling images of various and also enhances integrity protection of images Header containing information about target architecture, operating system, image type, compression method, entry points, time stamp, checksums, etc. The old, legacy image format concatenates the individual parts (for example, kernel image, device tree blob and ramdisk image) and adds a 64 bytes ThesĮimages can contain the linux kernel, device tree blob, root file system image, firmware images etc., either separate or combined. The mkimage command is used to create images for use with the U-Boot boot loader.
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