====== Petalinux ======

===== Building and Creating a Bootable Image for an SD card =====
<code bash>
# prepare the environment
source /tools/Xilinx/PetaLinux/2021.2/settings.sh
</code>

<code bash>
# configure
# [x] admin > sudo
# [x] misc > coreutils
# [x] misc > tiff
# [x] misc > gdb
# [x] libs > libusb-compat
# [x] libs > libusb1
petalinux-config -c rootfs

petalinux-config -c kernel
petalinux-config --get-hw-description=new_design.xsa

# build and package
petalinux-build
petalinux-package --boot --u-boot --fpga new_bitfile.bit --format BIN --force
petalinux-package --wic
</code>

<code bash>
# write to sdcard

lsblk
  ## sdc        7.4G 0 disk
  ## |_sdc1       2G 0 part   /media/sd1/boot
  ## |_sdc2       4G 0 part   /media/sd1/AAAA-BBBB

sudo dd bs=4096 if=images/linux/petalinux-sdimage.wic of=/dev/sdb
sudo sync
</code>

===== Backup and Restore =====
<code bash>
# back up bsp
petalinux-package --bsp -p . --clean -o ./new_bsp.bsp --force

# load bsp
petalinux-create -t project -s $PATH_TO_PETALINUX_PROJECT_BSP --tmpdir $TMPDIR PATH
petalinux-config --get-hw-description=new_design.xsa

# load new firmware without re-imaging sd card
scp /tftpboot/BOOT.BIN /tmp
cp /tmp /media/sd1/BOOT.BIN
reboot
</code>

===== Custom Kernel Modules =====
Create the kernel module.

Copy the dma-proxy.c file from the [[https://github.com/Xilinx-Wiki-Projects/software-prototypes/blob/master/linux-user-space-dma/Software/Kernel/dma-proxy.c|Xilinx Repo]]

<code bash>
petalinux-create -t modules --name dma-proxy --enable
vi project-spec/meta-user/recipes-modules/dma-proxy/files/dma-proxy.c

vi project-spec/meta-user/recipes-bsp/device-tree/files/system-user.dtsi
  / {
    dma_proxy {
      compatible ="xlnx,dma_proxy";
      dmas = <&axi_dma_0 0  &axi_dma_0 1>;
      dma-names = "dma_proxy_tx", "dma_proxy_rx";
    };
  };

  # if overlay enabled
  # $ vi project-spec/meta-user/recipes-bsp/device-tree/files/pl-custom.dtsi
  # / {
  #   dma_proxy {
  #     compatible ="xlnx,dma_proxy";
  #     dmas = <&axi_dma_0 0  &axi_dma_0 1>;
  #     dma-names = "dma_proxy_tx", "dma_proxy_rx";
  #   };
  # };
</code>

<code bash>
# disable overlay
# Option 1
petalinux-config
    DTG Settings
      [ ] Devicetree overlay

# OR Option 2
petalinux-config -c kernel
    Device Drivers > Device Tree and Open Firmware support
      [ ] Device Tree overlays
      
# enable module
petalinux-config -c rootfs

# verify module is in project-spec/meta-user/conf/user-rootfsconfig and project-spec/configs/rootfs_config

# build module and kernel
petalinux-build -c kernel
petalinux-build -c dma-proxy
petalinux-build -c rootfs
petalinux-build

# insert module (after booting up petalinux on the SoC or FPGA)
ls /dev | grep dma
modinfo dma-proxy
  #  filename:       /lib/modules/5.10.0-xilinx-v2021.2/extra/dma-proxy.ko
  #  license:        GPL v2
  #  description:    DMA Proxy Prototype
  #  author:         Xilinx, Inc.
  #  depends:
  #  name:           dma_proxy
  #  vermagic:       5.10.0-xilinx-v2021.2 SMP mod_unload aarch64
  #  parm:           internal_test:int
  
insmod /lib/modules/5.10.0-xilinx-v2021.2/extra/dma-proxy.ko
ls /dev | grep dma
    dma_proxy_rx
    dma_proxy_tx
</code>