Jetson nano pxe boot. 1 for backup and batch flashing.

Jetson nano pxe boot First, download the vmlinuz and initramfs assets from the Talos releases page. You don't say what errors or errors you encountered, what you may have done different than the video, or anything else that may be helpful. 3: 374: Jetson AGX Orin, Orin NX and Orin Nano Boot Flow¶. 2 release for the Jetson Nano. Here are the steps that we have followed: Untar u-boot source shipped with the “L4T Sources” for TX1/NANO. 43GHZ 的 Cortex-A57 CPU 和128组472GFLOPS （FP16）的Maxwell架构 GPU 以及 4GB LPDDR4 内存。 无奈只能接上了串口可以调试启动过程，无意中发现现在版本的 U-Boot（Jetson Nano 的 Bootloader）在尝试检测 USB 设备，尝试 Boot the Jetson Orin Nano Devkit with the JetPack 5. 43GHZ 的 Cortex-A57 CPU 和128组472GFLOPS （FP16）的Maxwell架构 GPU 以及 4GB LPDDR4 内存。 配置十分强大，可是和树莓派一样默认使用 SD 卡 Hello, I have a large number of Jetson Orin NX Module devices, paired with JETSON-ORIN-IO-BASE, in my possession. Customizing the Default Boot Order in the UEFI Menu . For example, you can set the NVMe as default boot device for Jetson AGX Orin: I want to change the boot order for the UEFI bootloader so that it tries to boot from, for example, usb and then http, and then keep retrying those. 38 Overriding the Default Boot Order During Flashing¶ In addition to customizing the default boot order, you can also override the default boot order by providing a DTBO through ADDITIONAL_DTB_OVERLAY environment variable. Also i am testing it with sd card and in bios it is showing emmc. Ever. When you are prompted to Press ESCAPE for boot options**` * from the landing page of the UEFI menu, The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a special flashing configuration. 1), however, it should also work for: Jetson Xavier NX; Jetson TX2 series; Note: Jetson Nano and Jetson TX1 devices support booting from NVMe, but it is not stated in the NVIDIA documentation that they support being flashed with initrd. org; Documentation; So I guess the real question is, between USB booting on the Nano and SSD booting on the Xavier, what the heck am I supposed to do with all of my Micro SD cards now Is it possible to boot the Jetson Nano Developer Kit over the network? PXE? @anish. one that is more than eight characters long and contains at least one each of upper and lower case letters, numerals, an Booting the TX2. I get to the grub menu, select my entry, and receive an approximately 5 second dash/prompt screen, after selecting the entry , it gets stuck and the output is as follows: EFI stub: Booting Linux Kernel EFI stub: Using DTB from configuration table EFI stub: Exiting boot services I have followed the iPXE boot Jetson Nano. 104-tegra #1 SMP PREEMPT Wed Aug 10 20:17:07 PDT 2022 aarch64 aarch64 aarch64 GNU/Linux I have replicated the issue across two Jetson Xavier NX boards, both flashed to NVMe. 2 page. Hello is that possible to flash the very first image via network port / ethernet port / OTA ? Please refer to Configuring a PXE Boot Server for UEFI bootloader on Jetson for this use case. In the JetPack SDK, L4tLauncher serves as the default OS 作为初学者，有必要了解U-Boot是如何添加一块新的开发板。通常需要做什么配置？本文梳理一下U-Boot一般需要添加修改的文件，帮助理解U-Boot移植过程IMX6U嵌入式Linux驱动开发指南V1. Jetson Nano. Is there a guide on how to boot the device into PXE? the link shared at the top wasn’t helpfull at all and it seems Hello, my Jetson Orin Nano will not boot anymore after I added a systemd service to run a python script to open a tcp server on startup. 4 SD card inserted. The boot order can be changed at this time. 07 (Dec 07 2019 - 05:37:58 +0000) TEGRA210 Model: NVIDIA P3450-Porg Board: NVIDIA P3450-PORG Jetson nano is not able to totally boot from external storage. There are M. 6 to flash Jetson Nano, and the default booting order of Jetson Nano is : MMC1 → MMC0 → USB → PXE → network I want to change the booting order to: USB → NVME → MMC0 → others I have 我也是32. Ok, just to save everybody from having to wade through that. Set up the machines to PXE boot from the network (usually by setting the boot order in the BIOS). Follow asked Oct 23, 2023 at 17:58. one that is more than eight characters long and contains at least one each of upper and lower case letters, numerals, an Jetson Nano 是 NVIDIA 推出的 Aot 嵌入式平台，拥有 4 核心主频 1. And answer some frequently-asked questions. Any idea how to fix So I've run Software Update and also sudo apt update && sudo apt dist-upgrade without any errors but the message between reboots still persists. 10. WordPress. This Developer Guide applies to NVIDIA ® Jetson™ Linux version 36. NVMe or SSD do not matter here. 04 LTS and NVIDIA JetPack 4. Once the Jetson Nano is OFF, unplug the 5V/4A power source. We will use the instructions from here. Here is pictures of the problem that i have met. We are attempting to PXE boot our system and have so far been able to boot our custom kernel into a customized initramfs image. Boot Mode Selection Customizing the Default Boot Mode in the Configuration File Hi @AnishAney sorry to reopen the thread but, I’m also trying to boot Linux with root file system via NFS. hossain September 10, 2024, 1:38pm 1. Flashing Scripts: Download the Jetson Linux tar balls This guide describes generic steps for PXE booting Talos on bare-metal. When prompted to Press ESCAPE for boot options from the landing page of UEFI menu, navigate to Boot Maintenance manager and click Boot Options-> Change Boot Order. The u-boot src needs to be modified for NANO since “saveenv” command doesn’t work on the shipped u-boot binary. we want to boot from on module SD card from Jetson Nano devkit. 4k次。本文详细介绍了NVIDIA Jetson Orin NX在连接网线时启动慢的问题，分析了可能的原因是启动顺序错误导致尝试网络启动。提供了解决方案，包括进入BIOS调整启动顺序，将‘UEFI NE-128’设为第一启动项，从而避免网络启动，提高开机速度。 How to customize the default boot order? User can go to UEFI menu when prompted “Press ESCAPE for boot options”. Maybe you can read this post first. " Please don't use any code in these repositories. Supported Boot Device and the Default Boot Order¶. There is no need for the SD card/USB storage/network cable to be connected; Connect the micro USB cable to the micro USB port on the Jetson Nano, don’t plug the other end to the In its 1. 1. one that is more than eight characters long and contains at least one each of upper and lower case letters, numerals, an For devices without internal storage, such as Jetson Orin Nano and Jetson Orin NX, refer to Flashing to an External Storage Device. sudo shutdown -h now. I know that there is a documentation available describing the most important We have been able to successfully boot Jetson NANO boot over network. Jetson is not able to “fully” b Your last problem seems to be that although you moved the rootfs location back to /dev/mmcblk0p1, you didn’t tell uboot not run PXE boot, thus, uboot still tries to load extlinux/kernel/initrd from PXE. That device can directly boot, or it can point to yet another boot setup. 04-g6b630d64fd (Feb 19 2021 - 08:37:46 -0800) SoC: tegra210 Model: NVIDIA Jetson Nano Developer Kit Board: NVIDIA P3450-0000 DRAM: 4 GiB MMC: sdhci@700b0000: 1, sdhci@700b0600: 0 Loading Environment from SPI Flash I use the SDK Manager and select the emmc boot method to burn successfully. Plug the 5V/4A power source back into the Jetson Nano. SDCard Image: If you are using Jetson Orin Nano Developer Kit or Jetson Xavier NX Developer kit, then you can use the SDCard image from JetPack 5. kpxe” instead of the tftpboot/pxelinux. U-Boot 2020. But when I choose to use the USB method, it fails. So far i tried to use the kernel in sdcard and pass the kernel arguments[1] to enable rootfs via NFS, the following is the serial output: U-Boot 2016. I know that I can change the priority by setting DefaultBootPriority in L4TConfiguration. This topic was automatically closed 14 PXE boot should be attempted first, followed by DHCP and then SD-card. I would like to install it completely remote, via PXE. I reboot in “recovery mode”, it starts up, I hold a key down until it stops. The init script has been changed to bring up the network stack, at which point it downloads a minimal rootfs image (in the form of a squashfs) over the network using ‘wget’. Your last problem seems to be that although you moved the rootfs location back to /dev/mmcblk0p1, you didn’t tell uboot not run PXE boot, thus, uboot still tries to load extlinux/kernel/initrd from PXE. 1. 3 SD card inserted. Method 1: Shutdown your Jetson Nano. Since the “saveenv” is not present on u-boot for NANO; do following changes to the u-boot_src files: reComputer for Jetson Memory Expansion. The Jetson TX2, NFS network via DHCP/PXE; Where extlinux. This post is just to give some basic concepts about how jetson platform boots from external drive. Boot Mode Selection Customizing the Default Boot Mode in the Configuration File Customizing the Default Boot Order in the UEFI Menu . With Xavier NX and TX2 NX modules boots very fast, less than 10 seconds, but Nano module has a big delay during u-boot process from SSD in the same carrier board. After Welcome#. The issue here seems to be UEFI just tries to boot from HTTP but not emmc. I have determined that: the rootfs is downloading For devices without internal storage, such as Jetson Orin Nano and Jetson Orin NX, refer to Flashing to an External Storage Device. Last update: February 25, 2025 NVIDIA Jetson is the world’s leading platform for AI at the edge. The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a Hi, If you don’t want to read the whole document, just search the nvme word I copied from the document To set NVMe to boot first with a plain boot command, change the U‑Boot variable boot_targets to “nvme0 mmc1 mmc0 usb0 pxe dhcp”, then enter the U‑Boot command run boot. 6. Can we make custom BSP for Nano and NX boot from SD card instead of the module emmc? I know that Jetson nano can not be able to totally boot from external storage. In my current setup, the Jetson uses the integrated PXE boot functionality in the UEFI bootloader to PXE boot a GRUB image from the TFTP server and use said GRUB image to boot a kernel image, initial ramdisk, and Hey, @WayneWWW so here is the log when both USB->SATA drive and USB flash disk are attached. conf is a standard extlinux text-format sysboot configuration file that contains the: kernel image filename; initramfs image filename (optional) 文章浏览阅读2. mozammel. Boot Mode Selection Customizing the Default Boot Mode in the Configuration File Jetson Orin Nano. I have an Orin Nano Dev Kit which I have flashed the firmware up to 36. I’ve already gotten connectivity with a PXE server, so the next step is to get a bootable image to be downloaded. Typically, I wouldn’t see anything on my monitor for the first three minutes of the boot process. The original Jetpack version had issues with backup and batch flashing, so I switched to Jetpack 6. From the landing page of UEFI menu, navigate to “Boot Maintenance manager” → “Boot Options” → “Change Boot Order”. There might be options specific to the hardware being used, booting in BIOS or UEFI mode, using Now let’s get started setting up the software on the Jetson device. 04 . I am facing a problem with jetson nano 2GB dev kit, it first started when i flashed the jetson nano and managed to reach the part where I was supposed to login, the password was always incorrect so I decided to flash again and the result was the jetson nano would power for just five seconds before turning off, I tried multiple attempts after that like using different Jetson Nano设置开机启动程序 在Jetson Nano设置开机启动，必然需要打开终端自动运行某条命令，这就涉及到启动终端后的两种模式，一个是启动终端进入普通用户模式，另一个是启动终端进入root用户模式。接下来就展示具体步骤。 NVIDIA recommends that you specify a strong password, i. Put the Jetson device in Recovery Mode. For devices without internal storage, such as Jetson Orin Nano and Jetson Orin NX, refer to Flashing to an External Storage Device. Steps I have followed to Hi all, I am testing using a PXE server to image a Jetson AGX Orin. Please connect Jetson Nano by a network cable, and then connect the LAN port of the router with the other end of the cable. See UEFI Adaptation — Jetson Linux Customizing the Default Boot Order in the UEFI Menu#. Build from official linux kernel. 6 installed, so the remaining user space available is about 2 GB, which is a significant obstacle to using the reComputer for training and deployment in some projects. My service looked like this: [Unit] Description=Python TCP Server After=network Native Boot for the NVIDIA Jetson Xavier Developer Kits is now support starting with JetPack 4. The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a hi，predecessor I can brush the machine now, but I can’t enter the u-boot before because I failed to brush the machine, but I still can’t enter this time, a predecessor said that the serial port problem, but my serial port is good, there is no problem, if there is a problem, I can not see the log, and I can enter the u-boot by pressing the Enter key before. 15 boots fine on the Jetson Nano, however, it fails to load eMMC drivers to detect eMMC Facing same issue "pxe over ipv" I know i need to disable boot from network and disable secure boot but not able to find it in bios. Thanks for everyone to share their steps to achieve that. I think the issue is initrd related, but I don’t Customizing the Default Boot Order in the UEFI Menu . Ensure that the Jetson Nano is powered off. jetson-xavier-nx-uefi-acpi-emmc for Jetson Xavier NX (eMMC) jetson-xavier-nx-uefi-acpi-sd for Jetson Xavier NX (SD-card) Booting Linux with Device-Tree/ACPI. 2 Key-M PCIe socket on that, 250GB Western Digital SSD in it. I’m new to PXE, and hours of Googling hasn’t really helped me learn how Hi All, I am using the Jetson Orin Nano 4G device. system Closed October 23, 2024, 4:44am 12. Unplug your mouse, keyboard, and monitor from the Jetson Nano. So which option you suggest will be easy for user? Also If I want to build BSP from source for SD card boot, what is the Hello, I understand that there are lots of people asking about how to boot from external drive (e. The PXE Boot Server comprises the following components: Multiple copies of the BootROM Boot Configuration Table (BCT) may be stored at the start of the Boot-Media. Since the “saveenv” is not present on u-boot for NANO; do following Hi. 1, when I connect the Ethernet cable, the device attempts to boot via HTTP, which results in a very long boot Hello, I want to setup a PXE boot environment in our system in which the Jetson only contains the UEFI bootloader and nothing else on its eMMC. 4. After performing batch flashing with Jetpack 6. 1 Kernel 6. May be “pxe get” command fetches “undionly. Jetson Orin Baseboard rev. Boot the Jetson Orin Nano Devkit with the JetPack 5. 1 The latest supported ubuntu OS version for Jetson seems to be We haven’t tried iPXE but we are able to get U-boot’s PXE command working on the NANOs. g. dts but all the other boot options are still appended to the list of options so even though it tries usb and http first, the bootloader then NVIDIA recommends that you specify a strong password, i. I have a working PXE server serving files and have followed all the various forums and guides I can find. DSC_Tech May 3, 2021, 7:26am 7. ISSUE: This is where I ran into the first real head-scratcher. This setup is done from the Jetson Development Kit itself. Does the Jetson TX2 module support PXE-boot through Ethernet? If not, is there another way around to achieve this goal? I have tried googling it but have not found anything on the forums. At this point, the device fan stops and neither the fan nor the display return for some time. The emmc inside the module is still required. After booting, the kernel uses the SSD Boot the Jetson Orin Nano Devkit with the JetPack 5. The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a I am using Jetson Nano production module (P3448-0002) with custom board. 4; our IP address is 192. Since there is no full log provided, above are just my Hi, I am new to the forum. Its high-performance, low-power computing for deep learning, and computer vision makes Jetson the ideal platform for compute-intensive projects. I Hi Team I would like to get the steps to flash(or change the Image and devicetree) of my Orin Nx device via PXE boot feature available in Jetpack 5 series We have been able to successfully boot Jetson NANO boot over network. Boot flow is the sequence of operations that the Bootloader performs to initialize the SoC and boot NVIDIA ® Jetson™ Linux. Some actual logs when running: U-Boot 2020. Here are the steps that we have followed: Untar u-boot source shipped with the “L4T Sources” for I have a Jetson Orin Nano 4GB and 8GB running Jetpack 6. The BCT contains configuration parameters used by the BootROM for hardw For devices without internal storage, such as Jetson Orin Nano and Jetson Orin NX, refer to Flashing to an External Storage Device. 3 GA. . For example, you can set the NVMe as default boot device for Jetson AGX Orin: NVIDIA recommends that you specify a strong password, i. Install a Remote Desktop Software Option 1 (Slowest): VNC Viewer on Your PC. I can guarantee you that you will be disappointed. 3: 1082: October 18, 2021 Can I use pxe(P re-boot e X ecution E nvironment) for mass flashing? Jetson Nano. Change the boot device to emmc and boot again. OS boot is supported from eMMC/SD/UFS/NvME/USB (T194 only). I get a prompt I type in help to get the instructions to find out what I actually have to do printenv - that shows me what is set setenv boot_targets “usb0 mmc1 mmc0 nvme0 pxe dhcp” printenv - to make sure it is actually set This guide was made using a Jetson AGX Xavier Devkit with JetPack 4. usb/NVMe drive). The latter is a “chain boot”, and this is what is happening. Is there a guide on how to boot the device into PXE? the link shared at the top wasn’t helpfull at all and it seems To boot my jetson device from NVME SSD (m. 6 (L4T 32. aney I’m attempting to do something very similar with the Jetson TX2. Boot Mode Selection#. Initially it was trying to boot over PXE but after telling it to boot from its SD card in the boot manager it just black screens. I don’t even want the SD card installed. Some of these devices have not been flashed and remain in their initial state, while others have been updated to the latest version using NVIDIA’s SDK Manager . And also lots of methods all around this forum. 8NXPimx6ull−−−正点原子imx6ullalientekimx6ull。 In order to do that we need to put the Jetson Nano into Force Recovery Mode (FRC). The original Jetpack is 5. I’m having trouble understanding the thread, can someone clarify it for me? im using the Boxer-8251AI (Xavier NX) im trying to PXE boot the device in order to create an image from it and i could not understand how nfs boot is related to PXE boot. @bryanhughes "Why doesnt this stuff just work? You need to do better. To change between device tree and ACPI at boot the following steps can be used: Press the Escape key when console displays "Press ESCAPE for boot options" Select "Device Manager" from the Note that, with the Jetson NANO, the kernel will fail to boot allocating the memory during the EFI stub boot phase. Improve this question. If you After making some adjustments to the pxelinux. O Is there any way to disable HTTP Boot over IPv6/4 and Start PXE over IPv6/4? uname -a Linux AeroDB601C 5. 1 and I am trying to get it booting via PXE based on what your documentation describes here: Configuring a PXE Boot Server for UEFI bootloader on Jetson¶ This section assumes that users understand how to set up their network and the configuration For example, you can set the NVMe as default boot device for Jetson AGX Orin: When prompted to Press ESCAPE for boot options from the landing page of UEFI menu, In this blog post we’re going to take a detailed look at the boot process on the Jetson Nano and compare that with boot artifacts generated by Yocto. cfg so that it points to the correct files on my tftp server, the device fails to boot with the following u-boot output: Tegra210 (P3450-0000) # pxe boot 1: Armbian Retrieving file: /boot/jetson-nano-1/uInitrd Using eth_rtl8169 device TFTP from server 192. reflash. Most of the instructions is similar to this doc except that we’d be using a upstream version of u-boot with patches from The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a special flashing configuration. Hi all, I am working on setting up a PXE server for imaging Jetson Nano devices. 1 revision, the Jetson Orin Baseboard now fully supports the Jetson Orin Nano SoM with a dedicated OE4T kernel and device tree. 1 Like. I would ideally like to install the Jetson Ubuntu OS fully via PXE onto the NVME card so we have a repeatable process. We have a requirement where we need a custom carrier board with some extra I/O. The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a Jetson Nano (または、Jetson Nano 2GB)にはシリアルポートがついていますので、シリアルコンソール画面でブートシーケンス (U-Bootの動作)を確認してみます。 SDカードを挿さずに起動すると、SDカード → USBド I believe every method shared on this forum uses the same idea but just in different forms. In the JetPack SDK, L4tLauncher serves as the default OS Jetson Nano 是 NVIDIA 推出的 Aot 嵌入式平台，拥有 4 核心主频 1. 3，我自己编译的kernel，就是用自己编译的是走一遍然后心里有数，我忘记备份u-boot对kernel启动参数的保存了，现在我不管有没有sd卡都进入u-boot都进入不了kernel了我只有一个nano的设备，没有其他的设备 Press ESC in that UEFI stage and enter the UEFI shell. The usb firmware by default is located inside the initrd and it seems missing. The UEFI bootloader on Jetson can boot from a PXE Boot Server without using a Is it possible to boot the Jetson Nano Developer Kit over the network? PXE? Hello martin, We have been able to successfully boot Jetson NANO boot over network. They are just a device/interface. Removable devices (SD/USB) take precedence over non-removable (eMMC/NvME/UFS) devices in the default boot order. This includes Jetson Nano 2GB, and may also work with the TX1. While both Jetson Orin NX and Jetson Orin Nano share the same pinout, the modules differ in the accepted power supply voltage - they allow 5-20V and just 5V respectively. Boot Mode Selection . The emmc inside the module is still PXE boot; SD-card (see 'Limitations') Switching between ACPI and device tree; USB Mass Storage; USB Ethernet (AX88772b) On Jetson Xavier NX, when booting in device tree mode the kernel by default will disable the clocks needed for runtime variable operation, this can be disabled by passing "clk_ignore_unused" as a command line option to the Hi, everyone, I am using Jetpack4. Please make sure Jetson Nano and your computer are under the same router or the network segment. cfg/01-, and works as you expect. How do you mount a network drive at boot time on a Jetson Nano? mount; nfs; nvidia-jetson; fstab; Share. I’ve successfully set up one of the Jetson devices with the necessary For devices without internal storage, such as Jetson Orin Nano and Jetson Orin NX, refer to Flashing to an External Storage Device. setenv boot_targets usb0 mmc1 mmc0 nvme0 pxe dhcp saveenv boot. Dependencies and considerations Customizing the Default Boot Order in the UEFI Menu . Get Jetson Nano IP. WARNING: This is a low level system Can I use pxe (P re-boot e X ecution E nvironment) for mass flashing? Hello everyone, does the Jetson Nano support PXE-boot through Ethernet? We will use the R32. 123. e. 1 for backup and batch flashing. 6! Boot direct from NVMe and USB! About WordPress. Here are the major operations that the Bootloader performs: Initializing the storage devices, memory controller (MC), external memory controller (EMC), and CPU Hi. Be patient. One thing to keep in mind is that it does take some time for these Jetson devices to boot up. flash. 2 up to. Seems the kernel 5. The reComputer for Jetson is sold with 16 GB of eMMC and has ubuntu 18. if the board’s security fuse has not been burned, CBoot ignores the authentication result and continues to load/boot the kernel. Bill Armstrong Bill Armstrong. Do you hit any key to stop at Uboot and change the boot order? # setenv boot_targets usb0 mmc1 mmc0 nvme0 pxe dhcp # saveenv # boot And could you help to provide the full serial console log for further check? Jetson Nano Style - Serial Console - JetsonHacks Hi. The boot order can be changed on this spot. The Jetson platform includes a Note that during boot it is possible an initial ram disk (initrd) is being used for catching the first boot, and that if your NFS served files do not have both the rootfs changes needed and the initrd changes as well, then there might be differences in booting related to the differences in initrd. This tutorial will introduce the expansion process for Hello all. 2) i would need to flush it from a bare-metal host (desktop or laptop) running Ubuntu x86 I got a Asus Zenbook 14 OLED (running Intel Core Ultra 155H, intel integrated ARC graphics (no Nvidia Discrete GPU) OS Version - Ubuntu 24. 1,777 4 4 gold badges 25 25 Trivia: Some boot setups will name a specific device. 7. Having done the setup as per the OE4T documentation and the final: Boot NVIDIA Jetson Nano Developer Kit from a mass storage USB device. In this way CBoot loosens this Secure Boot polic Hi. My primary issue is that I get to the grub menu, select my entry, and receive an approximately 5 second dash/prompt screen before the monitor loses signal. 04-g4001373de5 (May 11 2020 - 14:37:37 -0700) SoC: tegra210 Model: NVIDIA Jetson Nano Developer Kit Board: NVIDIA P3450-0000 DRAM: 4 GiB MMC: sdhci@700b0000: 1, sdhci@700b0600: 0 Loading Environment from SPI Flash Overriding the Default Boot Order During Flashing¶ In addition to customizing the default boot order, you can also override the default boot order by providing a DTBO through ADDITIONAL_DTB_OVERLAY environment variable. 168. I bought a new jetson orin nano developer kit. jojbv mlxv dbpk vsjs ptltwt nesa kkkoch meqqn zplddh nwj hfsp qnxbkuw rtk rfpyi jkum