Ax5soc Build linux image from scratch

reference: rocket https://www.rocketboards.org/foswiki/Documentation/BuildingBootloaderForAgilex5

OS: Ubuntu-22.04 (PC or Windows WLS)

----
'''1. Setting Up Environment'''
* Install the required packages on Ubuntu:
<pre>
sudo apt-get update
sudo apt-get upgrade
sudo apt install make bison flex python3-dev libssl-dev swig
sudo apt install u-boot-tools
sudo apt install qemu-user-static
</pre>
* Create top folder:
<pre>
mkdir ATUM_A5_V1.2.sdmmc
cd ATUM_A5_V1.2.sdmmc
export TOP_FOLDER=`pwd`
</pre>
* Download and setup the the toolchain as follows:
<pre>
cd $TOP_FOLDER
wget https://developer.arm.com/-/media/Files/downloads/gnu/11.2-2022.02/binrel\
/gcc-arm-11.2-2022.02-x86_64-aarch64-none-linux-gnu.tar.xz
tar xf gcc-arm-11.2-2022.02-x86_64-aarch64-none-linux-gnu.tar.xz
rm -f gcc-arm-11.2-2022.02-x86_64-aarch64-none-linux-gnu.tar.xz
export PATH=`pwd`/gcc-arm-11.2-2022.02-x86_64-aarch64-none-linux-gnu/bin:$PATH
export ARCH=arm64
export CROSS_COMPILE=aarch64-none-linux-gnu-
</pre>

'''2. Build Arm Trusted Firmware'''
<pre>
cd $TOP_FOLDER
rm -rf arm-trusted-firmware
git clone -b QPDS24.1_REL_AGILEX5_GSRD_PR https://github.com/altera-opensource/arm-trusted-firmware arm-trusted-firmware
cd arm-trusted-firmware
make -j $(nproc) PLAT=agilex5 bl31 
cd ..
</pre>
The following files is created:
* $TOP_FOLDER/arm-trusted-firmware/build/agilex5/release/bl31.bin (to used for u-boot.itb generation)



'''3. Build U-Boot'''
<pre>
cd $TOP_FOLDER 
rm -rf u-boot-socfpga 
git clone -b atuma5_v1.1 https://github.com/terasic/u-boot-socfpga u-boot-socfpga 
cd u-boot-socfpga 
make mrproper 
cp atuma5.config .config
# link to ATF 
ln -s ../arm-trusted-firmware/build/agilex5/release/bl31.bin 
make -j $(nproc) 
</pre>
The following files is created:
* $TOP_FOLDER/u-boot-socfpga/u-boot.itb
* $TOP_FOLDER/u-boot-socfpga/spl/u-boot-spl-dtb.hex


'''4. Creating the Boot Script'''
<pre>
cd $TOP_FOLDER 
rm -rf uboot-script && mkdir uboot-script && cd uboot-script
wget https://releases.rocketboards.org/2023.12/qspi/agilex5/agilex5_uboot.txt
wget https://releases.rocketboards.org/2021.11/uboot-script/agilex/uboot_script.its
mv agilex5_uboot.txt uboot.txt 
nano uboot.txt # content see bloew
mkimage -f uboot_script.its boot.scr.uimg
cd ..
</pre>

uboot.txt
<pre>
echo "Trying to boot Linux from device ${target}";

if test ${target} = "mmc0"; then
        echo "Found kernel in mmc0";        
        mmc rescan;
        fatload mmc 0:1 ${kernel_addr_r} Image;
        fatload mmc 0:1 ${fdt_addr_r} socfpga_agilex5_terasic.dtb;
        setenv bootargs "console=ttyS0,115200 root=${mmcroot} rw rootwait";
        booti ${kernel_addr_r} - ${fdt_addr_r};
        exit;
fi
</pre>
The following files is created:
$TOP_FOLDER/uboot-script/boot.scr.uimg
Edit
</pre>


'''5. Build Linux Kernel'''
<pre>
cd $TOP_FOLDER 
rm -rf linux-socfpga
git clone --filter=tree:0 -b atuma5_v1.2 https://github.com/terasic/linux-socfpga linux-socfpga 
cd linux-socfpga 
cp atuma5.config .config
make -j $(nproc) Image && make intel/socfpga_agilex5_atuma5.dtb 

make -j $(nproc) modules

make -j $(nproc) modules_install INSTALL_MOD_PATH=modules_install
rm -rf modules_install/lib/modules/*/build
rm -rf modules_install/lib/modules/*/source
</pre>
The following files is created:

* $TOP_FOLDER/linux-socfpga/arch/arm64/boot/Image
* $TOP_FOLDER/linux-socfpga/arch/arm64/boot/dts/intel/socfpga_agilex5_atuma5.dtb

'''6. Build Ubuntu 22.04.3'''
<ol start="1">
<li>Prepare rootfs folder</li>

<pre>
cd $TOP_FOLDER
mkdir -p rootfs
cd rootfs
</pre>
<li>Switch to root privilege</li>
<pre>
sudo -s
</pre>
<li>Download the Ubuntu 22.04.3 root filesystem</li>
<pre>
wget -c https://cdimage.ubuntu.com/ubuntu-base/releases/22.04.3/release/ubuntu-base-22.04.3-base-arm64.tar.gz
tar xvf ubuntu-base-22.04.3-base-arm64.tar.gz
rm ubuntu-base-22.04.3-base-arm64.tar.gz
</pre>
<li>Copy qemu-user-static</li>


</ol>