DKSF_69_system consists of three components:
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- u-boot bootloader - this component is not meant to be changed by the user via the web. U-boot is programmed at production facility using MFGTool only.

- linux kernel - This component can be programmed via the web upgrade process (there are two alternate kernel images on the device)

- rootfs - component can be programmed via the web upgrade process. (there are two alternate rootfs images on the device)

Source repository structure:
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buildroot-2014.08 - This folder contains source code and build project for root file system. It includes all applications such as the web server and the application utility pwr220_16 that does all the work

linux-3.9.11 - Linux kernel source code and build project

u-boot-2013.4 - U-boot source code and build project

Building the source code:
=========================

Building the rootfs:
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1. Change to buildroot-2014.08
2. For a full rebuild, do
make clean
make
3. Full rebuild may take long time (depending on your PC spec), on i7-4790K takes under 1 hour.
4. When build is complete, the resulting output rootfs image file is
/buildroot-2014.08/output/images/rootfs.tar.bz
5. This file can then be either uploaded using the web (when the support for it is complete) or
copy to MFGTool/Profiles/MX28 Linux Update/OS Firmware/files before programming into flash using MFGTool
6. It is often easier to just rebuild only the package that's needed, to do that:
make pwr220_16-clean
make
The above steps rebuild the pwe220_16 package and rebuild the new rootfs image in the /output/images

Building the linux kernel:
--------------------------
1. Change to linux-3.9.11
2. Execute the following commands:
make mrproper - full clean
make -j2 CROSS_COMPILE=/opt/arm-2011.03/bin/arm-none-linux-gnueabi- ARCH=arm mxs_defconfig
make -j2 CROSS_COMPILE=/opt/arm-2011.03/bin/arm-none-linux-gnueabi- ARCH=arm menuconfig (save without changes)
make -j4 CROSS_COMPILE=/opt/arm-2011.03/bin/arm-none-linux-gnueabi- ARCH=arm uImage (result in /arch/arm/boot)
make -j4 CROSS_COMPILE=/opt/arm-2011.03/bin/arm-none-linux-gnueabi- ARCH=arm imx28-evk.dtb (to build dts file)
3. The resulting uImage file can be used for web upgrade or can be programmed using MFGTool - copy it to:
MFGTool/Profiles/MX28 Linux Update/OS Firmware/files before programming into flash

Building the U-boot:
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cd u-boot-2013.4/
./make_clean.sh
make mx28evk_nand_config
./make_uboot_sb.sh
Copy uboot.sh to MFGTool files folder, should be renamed imx28_ivt_uboot.sb
Folder location: MFGTool/Profiles/MX28 Linux Update/OS Firmware/files