update petalinux section

Author: dhm2013724

petalinux/README.md

@@ -1,11 +1,11 @@
 # PetaLinux
-Recently, I have tried to implement YOLOv2 Accelerator in PetaLinux v2018.2. And here, I just want to share the experience and PetaLinux create steps to help other people re-implement this accelerator.(In Ubuntu 16.04 with Vivado v2018.2 and PetaLinux 2018.2)
+If you want to create your own Petaliunx verison based on specfic hardware design, pls follow below steps.
 
 ## Prepare for Petalinux
-First, make sure that you have installed PetaLinux and Vivado in Ubuntu 16.04(See the official Xilinx manual and User Guide or just google or bing it) . After you have installed PetaLinux and Vivado, you should source related settings.sh in order to use petalinux and cross-compiler tool-chain in shell. like these two cmds: __source /opt/pkg/petalinux/settings.sh__ and __source /opt/Xilinx/Vivado/2018.2/settings64.sh__. Then, copy two files (hardware description file __design_1_wrapper.hdf__ and bitstream file  __design_1_wrapper.bit__ that generated from Vivado project)to one directory.
+First, make sure that you have installed PetaLinux and Vivado in Linux env (See Xilinx's PetaLinux Tools Documentation: Reference Guide (UG1144)) . After that, you should source related settings.sh in order to use petalinux and cross-compiler tool-chain in shell. like these cmds: __source 2019.2/petalinux/settings.sh__ and __source 2019.2/Vivado/2018.2/settings64.sh__. Then, copy two files (hardware description file __design_1_wrapper.hdf__ and bitstream file  __design_1_wrapper.bit__ that generated from Vivado project)to one directory (suggest include the bitstream within hdf file).
 
 ## Create PetaLinux Project and modify the Device-tree to reserve memory
-Use petalinux-create cmd to create one petalinux project. If you dont know how to create one project, you can type __petalinux-create -h or --help__ to get help and more informations. Here, I just type __petalinux-create -t project -n yolov2 --template zynq__ to create a petalinux project named yolov2. Then, __cd yolov2/project-spec/meta-user/recipes-bsp/device-tree/files/__ to find the __system-user.dtsi__ and modify it like below:
+Use petalinux-create cmd to create one petalinux project. If you dont know how to create one project, you can type __petalinux-create -h or --help__ to get help and more informations. Here, I just type __petalinux-create -t project -n yolov2 --template zynqMP__ to create a petalinux project named yolov2. Then, __cd yolov2/project-spec/meta-user/recipes-bsp/device-tree/files/__ to find the __system-user.dtsi__ and modify it like below:
 
 ```
 /include/ "system-conf.dtsi"
@@ -55,20 +55,79 @@ Here, I just follow the wiki to reserve one continued memories for yolov2(Zedboa
 [https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841683/Linux+Reserved+Memory](https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841683/Linux+Reserved+Memory)
 
 ## Config project with .hdf file
-Third, back to the project directory __yolov2/__, and use type this cmd to initilize your project: __petalinux-config --get-hw-description DIR_where_you_put_the_design_1_wrapper.hdf__. Then, it will come to one menu like below:
-![hdf_config.jpg](https://github.com/dhm2013724/yolov2_xilinx_fpga/blob/150MHzTn4Tm32Tr26Tc26Cin4Cout2/petalinux/hdf_config.jpg)
+Third, back to the project directory __yolov2/__, and use type this cmd to initilize your project: __petalinux-config --get-hw-description DIR_where_you_put_the_design_1_wrapper.hdf__. In menu __Subsystem AUTO Hardware Settings__, check your board's UART and SD/SDIO config (some boards have multiple UARTS).
+THen, in menu __Image Packaging Configuration__, select __INITRAMFS__ option, and set INITRAMFS/INITRD Image name as __petalinux-image-minimal__. (Here, just follow UG1144).
 
-Here, I like to set rootfs from SD card(Just set __Image packaing configration-->file system type or rootfs(I forgot it...)--> SD card__). So that, the files that you used can be saved in SD card when you power-off it. And, then save configuraiton and exit. You will have to wait for a long time(I think that it will donwloads somethings from Internet or just do some configs. Make sure that your computer can access the Internet).
+## SSH config
+For SSH, just mutually select openSSH or dropbear, otherwise the ssh's speed would be very slow.
 
-## Further config or build project
-If you have other configuraitons, you can use __petalinux-config or petalinux-config -c XXX__ to further config this project. More informations are available in __petalinux-config -h__. After configuraiotn, you can type __petalinux-build__ to build the whole project. After that, type __petalinux-package -boot --fsbl image/linux/zynq_fsbl.elf --fpga --u-boot --force__ to generate BOOT.BIN. Finally, you will get three files for petalinux: __BOOT.BIN, image.ub and rootfs.cpio__.
-![package.jpg](https://github.com/dhm2013724/yolov2_xilinx_fpga/blob/150MHzTn4Tm32Tr26Tc26Cin4Cout2/petalinux/package.jpg)
+OpenSSH RootFS Configuration.‌‌
+$ petalinux-config -c rootfs
 
-## Partition SD Card and unzip rootfs
-Just use Disks tool in ubuntu to partition SD card into two file systems: one FAT and one EXT4. Copy BOOT.BIN and image.ub into FAT file system and copy rootfs.cpio into EXT4 fs.(If you meet permission denied, use sudo). In EXT4 fs, type cmd __sudo pax -rvf rootfs.cpio__ to unzip the rootfs. Then, umount EXT4 and FAT. Here, the Petalinux has been implemented.
+Filesystem Packages - console - network - openssh - openssh‌‌ →  Y
+
+Filesystem Packages - console - network - openssh - openssh-*‌‌ →  Y
+
+Image Features - "imagefeature-ssh-server-openssh"‌‌ →  Y
+
+Filesystem Packages - console - network - dropbear‌‌ →  N
+
+Image Features - "imagefeature-ssh-server-dropbear"‌‌ →  N
+
+Filesystem Packages - misc - "packagegroup-core-ssh-dropbear" - "packagegroup-core-ssh-dropbear"‌‌ →  N
+
+
+DropBear RootFS Configuratoin.
+$petalinux-config -c rootfs
+
+Filesystem Packages - console - network - dropbear‌‌ →  Y
+
+Image Features - imagefeature-ssh-server-dropbear‌‌ →  Y
+
+Filesystem Packages - misc - packagegroup-core-ssh-dropbear - packagegroup-core-ssh-dropbear‌‌ →  Y
+
+Filesystem Packages - console - network - openssh - openssh‌‌ →  N
+
+Filesystem Packages - console - network - openssh - openssh-*‌‌ → N
+
+Image Features - imagefeature-ssh-server-openssh‌‌ →  N
 
-## Download related files and Test YOLOv2 Accelerator
-Use ssh or other protocol to transmit related files into EXT4 fs, files that yolov2 accelerator needs are available in previous steps. like below:
-![yolov2_files.jpg](https://github.com/dhm2013724/yolov2_xilinx_fpga/blob/150MHzTn4Tm32Tr26Tc26Cin4Cout2/petalinux/files_that_yolov2_need.jpg)
-type cmd __chmod 777 yolov2_4port_n4m32.elf__ to make it can be executed. Then, type __./yolov2_4port_n4m32.elf one_pic_name.jpg__ to test it. Then, you will get the prediction results and saved as one picture named __predictions.png__.
-![output.jpg](https://github.com/dhm2013724/yolov2_xilinx_fpga/blob/150MHzTn4Tm32Tr26Tc26Cin4Cout2/petalinux/output.jpg)
+## Root login
+Then, for some new Petalinux veriosn (2021 or later), default login is not root, if you want to modify it, just follow:
+75610 - PetaLinux: How to SSH and SCP to Xilinx Evaluation Boards As The root User Using Dropbear
+2021年9月23日•Knowledge
+TITLE
+75610 - PetaLinux: How to SSH and SCP to Xilinx Evaluation Boards As The root User Using Dropbear
+DESCRIPTION
+In PetaLinux or Yocto, how can I SSH and SCP to Xilinx Evaluation boards as the root user using dropbear?
+
+SOLUTION
+In Yocto or PetaLinux, root login is disabled by default for SSH or SCP.
+
+In order to allow SSH as the root user you need to enable the "debug-tweaks" feature in PetaLinux or Yocto using any of the below methods.
+
+In 2019.2 and prior releases, enabling debug-tweaks also enables auto-login.
+This procedure applies to both Xilinx Evaluation and Custom boards.
+PetaLinux:
+
+Method 1:
+
+In 2019.2 and prior releases, you can enable debug-tweaks from the petalinux-config options as shown below.
+
+
+$ petalinux-config ---> Yocto Settings ---> [*] Enable Debug Tweaks
+
+In 2020.1 and later releases, you can enable debug-tweaks from the petalinux-config options as shown below.
+
+$ petalinux-config -c rootfs ---> Image Features ---> [*] debug-tweaks
+
+$ petalinux-config -c rootfs ---> Image Features ---> [*] auto-login
+
+[75610 - PetaLinux: How to SSH and SCP to Xilinx Evaluation Boards As The root User Using Dropbear](https://support.xilinx.com/s/article/75610?language=en_US#:~:text=In%20Yocto%20or%20PetaLinux%2C%20root%20login%20is%20disabled,and%20prior%20releases%2C%20enabling%20debug-tweaks%20also%20enables%20auto-login.)
+
+## build project
+After configuraiotn, you can type __petalinux-build__ to build the whole project. After that, type petalinux-build
+petalinux-package --boot --format BIN --fsbl images/linux/zynqmp_fsbl.elf --fpga images/linux/system.bit --u-boot --force to generate BOOT.BIN. Finally, you will get three files for petalinux: __BOOT.BIN, image.ub and rootfs.cpio__.
+
+## Partition SD Card and unzip rootfs
+Just use Disks tool in ubuntu to partition SD card into two file systems: one FAT and one EXT4. Copy BOOT.BIN and image.ub into FAT file system. (because INITRAM use memory ram as rootfs included in BOOT.BIN)