====== Boot and Kernel configure & build with PetaLinux 2018.3 without BSP (board support package)  ======

  - Create Vivado design and export the hardware with bitstream.\\ Default hdf (hardware description file) location is: <code>
<project_directory>/<project_name>.sdk/
</code> In case you need it (but usually you shouldn't), default bitstream location is: <code>
<project_directory>/<project_name>.runs/impl_1/
</code>
  - Setup PetaLinux enviroment (see [[hw:zynq:linux:petalinux:start|Install PetaLinux]])\\ \\
  - Create PetaLinux project: <code>
petalinux-create --type project --template zynq --name <boot_project_name>
cd <boot_project_name>
</code> For UltraScale+: <code>
petalinux-create -t project --template zynqMP --name <boot_project_name>
</code>
  - Get hardware description from Vivado project: <code>
petalinux-config --get-hw-description <path_to_vivado_project_directory>/<project_name>.sdk/
</code>
  - Set booting from SD card by navigating through settings tree and choosing the proper options: <code>
Subsystem AUTO Hardware Settings -> Advanced bootable images storage Settings -> boot image settings  : set ‘image storage media’ option to ‘primary sd’
                                                                              -> kernel image settings: set ‘image storage media’ option to ‘primary sd’
                                                                              -> dtb image settings   : set ‘image storage media’ option to ‘primary sd’
Image Packaging Configurations: set ‘Root filesystem type’ option to ‘SD card’
                              : uncheck 'Copy final images to tfpboot'
</code> Select ''Exit'' to write the configuration.\\ \\ In case you want to reconfigure boot settings, run: <code>
petalinux-config
</code>
  - Check whether all required drivers/modules are enabled in kernel config: <code>
petalinux-config -c kernel
</code> Hint: you can use vim-like search ''/<search_string>'' to list all enabled drivers/modules.\\ **Remember to __Save__ changes before exit -- it seems that there is no autosave!** \\
  - In order to use the generic UIO driver ''uio_pdrv_genirq'' enable kernel modules in kernel config: <code>
petalinux-config -c kernel
</code> by navigating through settings tree and enabling modules (there should be '<M>', not '<*>'): <code>
Device Drivers -> <*> Userspace I/O drivers -> <M> Userspace I/O platform driver with generic IRQ handling
                                               <M> Userspace platform driver with generic irq and dynamic memory
</code>
  - In order to use the generic UIO driver modify the device tree to assign the compatibility with this driver to your hardware: <code>
vim ./project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi
</code> and add the entry at the end of this file: <code>
&axi_gpio_0 {
	compatible = "generic-uio";
};
</code> for every hardware module you have.\\ Please notice that ''axi_gpio_0'' __is only an example__ of module name!
  - Fix the u-boot bug -- a typo in default boot command.\\ The proper boot configure entry: <code>
default_bootcmd=run uenvboot; run cp_kernel2ram && bootm ${netstart}
</code> is created by PetaLinux as <code>
default_bootcmd=run uenvboot; run cp_kernel2ram && run cp_dtb2ram && booti ${netstart} - ${dtbnetstart}
</code> with the typo in ''booti'' instead of ''bootm'' command.\\ \\ To fix this bug, edit the ''platform-top.h'' file (it would not be overwrite if you reconfigure the boot or kernel): <code>
vim ./project-spec/meta-user/recipes-bsp/u-boot/files/platform-top.h
</code> and add the following entry at the end: <code>
/* Due to a bug where having u-boot load dtb from SD card causes the boot
 * command to default to using booti instead of bootm on Zynq, the defult build
 * fails to boot. This boot command override is a temporary workaround.
*/
#ifdef CONFIG_BOOTCOMMAND
#undef CONFIG_BOOTCOMMAND
#define CONFIG_BOOTCOMMAND	"run uenvboot; run cp_kernel2ram && run cp_dtb2ram && bootm ${netstart} - ${dtbnetstart}"
#endif
</code>
  - Build the boot and kernel: <code>
petalinux-build
</code>
  - Determinate the bit file name in PetaLinux project (it is copied automatically from Vivado design by ''--get-hw-description''): <code>
ls ./images/linux/*.bit
</code>
  - Create ''BOOT.BIN'' image: <code>
petalinux-package --boot --format BIN --fsbl ./images/linux/zynq_fsbl.elf --fpga ./images/linux/<bit_filename>.bit --u-boot
</code>