Cross compile kernel. For the query How the C library works in cross-tools.

Cross compile kernel Related. My Pi 2 run out of RAM before by setting to 0 (auto, it eventually uses 5 threads) and i couldn't compile the toolchain (the kernel killed the compiler as it uses too much RAM). Hot Network Questions Quartz crystals: Is it "load capacitance" or "loading You can cross compile the kernel modules by running a make linux command from the SDK's top directory. Prerequisites. 1. cross compile raspberry pi kernel module. Cross Compile Android and Dependencies. When installing a cross-compiled kernel, you need to get the kernel and related files into the SD card. You can find the subtasks and other build targets in the Makefile. 34. But, it seems not working. Then follow the instructions given at the end of the command used to build the kernel (see above). e for Available system calls and their numbers, Constant definitions, Data structures, etc. user3215598 user3215598. 04-based environment for cross-compiling Raspberry Pi kernel. /boot/kernel7l. Since i didn't get how to compile just kernel modules in a standalone way, i decided to cross-compile the entire kernel and take the modules i needed. Ongoing work has allowed for Clang and LLVM utilities to be used as viable substitutes. In this section, you will find how to get the Jetson Orin AGX BSP sources and cross-compile to generate the kernel image and modules. user3215598. The Linux kernel has always traditionally been compiled with GNU toolchains such as GCC and binutils. For other platdorm just adjust ARCH, KERNEL, and CROSS_COMPILE envs. ; linux-libc-dev: Linux Building the toolchain works fine but when using it to cross-compile the Linux kernel (Using the multi_v7_defconfig from kernel version 4. System on a Chip¶. The kernel should be installed into the sysroot so if desired to cross-compile packages which include kernel modules, the process will be transparent. How to cross compile is easy, just install the appropriate cross compiler, and in the config set the target architecture and the compiler and build it as normal. Makefile for building library across multiple architectures. 2 Release, and faild. So I wish that I can compile kernel on PC and compile modules on Pi. 140-tegra SMP preempt mod_unload Cross-compiling of kernel module for ARM architecture. Drone), linux-2. --with-fpu=vfp declares to use the “vector floating point” unit of the ARM I can't remember, right now, if 2. source. But none of them can start correctly. Do make. You know what to do next. g: qemu) testing on non-native architectures becomes easier The above explanation is slightly broad; let’s make it more focused on the kw context, i. I am looking into cross compiling a kernel module for an ARM linux. Cross Install. If CROSS_COMPILE is not specified, the --target=<triple> is inferred from ARCH. In the Rules. 8. 9 failed to compile. CF is often used on the command-line like this: Fortunately, cross-compilation is part of the kernel DNA; as a result, Linux provides options such as CROSS_COMPILE and ARCH that allow developers to indicate which cross-compile and architecture they want to use to build their kernel. 1 Packaging a single kernel module; 8. Cross-compiling on a powerful host enables quick detection of kernel compile errors and config errors, as shown in the stable queue builds project. Four approaches to creating a specialized LLM. 0 target: ARM machine (Parrot AR. Change the make file of the kernel module to set the compiler as CROSS_COMPILE. --with-sysroot gives the sys-root on the host, containing header and libraries compiled for the target system. Author: Ziheng Jiang, Lianmin Zheng. , let’s talk about cross-compiling the Linux kernel. You might as well at this point rebuild the entire kernel. 1 2 3 4 GCC is the Traditional Default C Compiler used in the Linux kernel back then and now. If you use only LLVM tools, CROSS_COMPILE or target-triple-prefixes become unnecessary. Cross Compile Linux Kernel Module. I have tired to build kernel and modules directly on Pi, it is fine. The Overflow Blog Even high-quality code can lead to tech debt. I have done this earlier for another custom build imx233 board - in that case I had configured the kernel build system (LTIB) to leave the kernel sources and rootfs intact after building the image. cpp $(CXX) $(INCLUDES) $(CPPFLAGS) $(CXXFLAGS) -c $^ -o $@ ozw-power-on-off. 24. Right? If not, here is a hint: $ . However, by default, the kernel is compiled for the native architecture of the machine doing the compiling (x86_64 in my case). A System on a Chip (SoC) is an integrated circuit (IC) that integrates an entire system onto it. 0. Making your package ready for cross-compilation. The difference is just the name of the kernel— kernel. Hot Network Questions Must one be a researcher at a university to become an author of a research paper? Qt cross-architecture development in Debian by Enrico Zini . ; linux-image: The kernel image and the associated modules. PHONY: ozw owz: ozw-power-on-off. deb generated to the target Raspbery Pi, for example using scp. Mainline – Download CROSS_COMPILE¶ Specify an optional fixed part of the binutils filename. Build the kernel Now instead use make menuconfig we will use . Note, that documentation usually notes only the minimal compiler version. 3. Follow If you look at the Pi kernel source -- it is distinct from the mainline "vanilla" kernel -- on github, you can see by the top level Makefile the current stable is 4. mk_kernel: The name of the kernel config file. CF¶ Additional options for sparse. Example: arm if you want to compile a kernel for the arm architecture when I have cross-compile kernel to TEGRA_KERNEL_OUT path, how can I cross-compile external kernel module next? I follow NVIDIA Tegra Linux Driver Package Development Guide 32. Thanks to its Debian-based OS, Raspberry Pi offers a robust developer experience. Jetson AGX Xavier. g: qemu) testing Cross-compile a kernel for a system with flair! The relevant kernel sources should be installed first. 140-tegra SMP preempt mod_unload cross compile kernel module faild. 10. I have this configuration in my makefile: There is no requirement that CROSS_COMPILE should start with ARCH, it is just a convention. Note: This step is required if you want to have kernel files outside docker. a. It then uses that to do a full world build, where world means basically everything except the kernel and kernel modules; The architecture to cross-build. – Will. 6 Overriding kernel packages; 8 Patching a single In-tree kernel module. Guidelines for cross-build packaging. Before Kernel v5. However, the manufacturer doesn't provide it, nor it's baked into the kernel via CONFIG_IKCONFIG. To compile the driver (aka kernel module), I need the linux headers for the kernel used in the device, for which I need . For instance, maybe your project is large and your board doesn’t have enough It is possible to use the cross compiled kernel as a drop in replacement for the running kernel by replacing the kernel on the file system (e. To find the latest release for that version, start with the next one I try to crosscompile the linux kernel 3. linux-headers: The kernel headers, required when compiling any code that interfaces with the kernel. . - Check the docs for that kernel (README, Documentation/Changes, and so) or google. You can try set it to 2 or 3 for faster build, but 1 should be the safest. Linaro's GCC toolchain of varoius versions can be directly found here. config file) How to set KDIR path? The Path where linux_kernel_2. 6. Let me explain it by using an example. Earthly simplifies the build process for cross-compilation. But there's something I am not quite getting from various how-tos. – Why Ubuntu (vendor) kernel? Why cross-compile? Create flavour and build natively on Enzian "Shallow-fork" the vendor tree; Set up kernel flavour; Cross compile. 17 you need to give CROSS_COMPILE= on the command line when cross-compiling, e. Attempt #1: invoking the rule with arch=arm64; Attempt #2: dpkg-buildpackage; Attempt #3: set up sbuild and a focal chroot; Emulated native build with qemu-user-static and binfmt_misc I find the real problem is the kernel tools contained in the scripts dir must be compiled as native formats, which may assistant kernel building. Cross compilation for ARM board? Hot Network Questions Whose logo for an invited seminar in another university? What if a potential This article discusses how to cross-compile for Raspberry Pi efficiently. E. /scripts/rt-patch. However, it is easy to forget to use these parameters or mess with global variables, especially if you are doing it for the first time. 0 is the same as compiling with GCC 4. s:43: Error: selected processor does not support 'dmb ish' in ARM mode While normally not possible on embedded platforms, it is possible to build kernels on your Raspberry Pi with its luxurious root file system. 1. Below the script file and kernel config patch would work together to The standard way to do cross-compilation is to just override the compiler/linker. PART A: Cross Compile U-Boot and Linux Kernel 1. That means if you use only LLVM tools, CROSS_COMPILE becomes unnecessary. This tutorial introduces cross compilation and remote device execution with RPC in TVM. 0. bin) and reboot. It can be a nice "hack" if we The Linux kernel, by necessity, needs to run on a wide variety of architectures. 14. Linux KernelのImageやDevice TreeをARM用にクロスコンパイルする方法 Linux 64-bit binaries for the Aarch64 Linux cross-toolchain $ wget https: {PATH}の配下に"aarch64-linux-gnu-gcc"や"aarch64-linux-gnu-g++"がある) export CROSS_COMPILE = "aarch64-linux-gnu-" # 同時に実行可能なジョブ(コマンド)数の Cross Compiling Linux Arm Kernel with new driver module. Cross-compiling Linux kernel using crosstool-ng based toolchain. 2 Replacing default kernel modules; 9 Sysctls; 10 Troubleshooting. Cross compile module with arm-eabi-gcc. As compare to compile kernel, compiling simple modules is fast and easy. img or kernel7. When compiling and building cross-tool chain during configuration they will provide sysroot. Do I need to cross-compile the kernel first? How? Yes you do. It is useful when the remote device resource are limited, like Raspberry Pi and mobile platforms. Export the cross tool chain path in your host PC using export command. L2 cache or branch prediction) I cannot find anything (with search). 2. The file contains: # 'source' this script in your shell export VERSION=gcc-linaro-7. If you pick the cross compiler wrongly, the following may happen: $ make ARCH=arm CROSS_COMPILE=${CC} distclean $ make ARCH=arm CROSS_COMPILE=${CC} am335x_evm_defconfig $ make ARCH=arm CROSS_COMPILE=${CC} Linux Kernel. . 19; make ARCH=mips CROSS_COMPILE=mips64-linux-gnuabi64- oldconfig; make ARCH=mips CROSS_COMPILE=mips64-linux-gnuabi64- KDEB_PKGVERSION=1 -j`nproc` bindeb-pkg; Download the source. It always stop at ## B Cross Compiling¶ A single Clang compiler binary (and corresponding LLVM utilities) will typically contain all supported back ends, which can help simplify cross compiling especially when LLVM=1 is used. 20 for RISC-V. It is defined by the name of the subdirectory in arch/ in the kernel sources . As the config (1) program used to create header files and Makefile for a kernel build is platform specific, it is necessary to use the nbconfig program that's part of a newly created toolchain (created for example with /usr/src/build. 19. 1-2018. gz is extracted?. 4, you point the CROSS_COMPILE variable at the GCC 9. tar. Linux kernel images; Task Description Hi, I need help to cross-compile the kernel, in refer to this post. o all: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules In gcc, I would use the -m32 flag but in this case, I don't know how the Kernel compilation works, so I I try to crosscompile the linux kernel 3. 27. 5 Compiling Linux with clang; 7. For the query How the C library works in cross-tools. img. 70) I get a whole bunch of the following error: /tmp/ccMrtEje. This is different from traditional compilation, where code is compiled for the same platform on which it will be executed. 14 much time for my beaglebone black with different ARCH(x64, i386) and different toolchain. 8 (this works ok). This script will build the kernel, modules, device tree binaries and copy them to the deploy directory. I have Zynq target running on 3. Open a terminal and run the following commands to export the environment variables that will be used Cross Compilation and RPC . Part 5. If you pick the cross compiler wrongly, the following may happen: I am trying to build a simple Linux Kernel Module for the Ariane RISC-V implementation. o $(CXX) -o $@ Install cross tool chain in your host PC. It's a lot simpler if you build the kernel on the Pi itself, but the whole process can take hours to Copy the Debian packages *. However, at times, it can be difficult to compile programs. config file) Starting with Kernel v5. 1 Build fails. 1 Too high ram usage; "Can anyone please guide how to compile linux perf tools and dependent kernel module from scratch/source. out ozw-power-on-off. Am I missing any additional steps? linux; linux-kernel; cross-compiling; kernel-module; Share. Must I cross-compile modules if the kernel is cross-compiled? 1. 0 toolchain (or use PATH and update the CROSS_COMPILE prefix to match) and go from there. debian-cross mailing list The meaning of the arguments to configure:--prefix gives the Binutils install location on the host. You are now building tools required for the build for ARM and try to run them on Windows. The most frequent change in that Makefile is the version number, so if you look at its commit history you can find the first commit using 4. sh apply-patches the kernel version is : Linux nvidia-desktop 4. The method for actually compiling the kernel is all the same. To find the latest release for that version, start with the next one Specifying cross-compilation. Move the . Debian cross build quality assurance. Cross-compilation is often used in embedded systems where the development platform To cross-compile a kernel for AArch64 on Ubuntu, you need to install gcc-aarch64-linux-gnu, and run the build as make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Ability to cross-compile non-natively on an widely available architecture helps detect compile errors Coupled with emulation environments (e. In this post, I will discuss how to successfully cross-compile any program for any architecture in the Linux kernel. Building kernel, however, as you know, is much more time consuming. ARMv7 (32-bit) ARM qemu emulating vexpress-a9 board I use this command to recompile the kernel on xavier. Hot Network Questions Why does a rod move faster when struck at the center If you look at the Pi kernel source -- it is distinct from the mainline "vanilla" kernel -- on github, you can see by the top level Makefile the current stable is 4. "CROSS_COMPILE" for gcc cross platform compile settings "PATH" for the make procedure being able to find the cross platform compiler tools; The settings of these environment variables can be found in Install Xilinx tools page; Input Files Required. 41. If you are cross-compiling the kernel, ensure that the CROSS_COMPILE environment variable is set as described in preceding sections. Nick Desaulniers , a software engineer at Google, is contributing to the Linux kernel build system (kbuild) by submitting and contributing kernel patches. /make menuconfig. With cross compilation and RPC, you can compile a program on your local machine then run it on the remote device. That means that the kernel is compilable by any gcc released before the kernel: the kernel documentation is rarely updated just because new gcc is released. --with-arch gives the CPU architecture of the target system. asked Jan 21, 2014 at 18:35. Featured on Meta We’re (finally!) going to the cloud! Updates to the upcoming Community Asks Sprint. Debian bootstrapping. The kernel version on my Compiling gcc as a cross compiler should be fairly simple, however I have never attempted it on Windows. 140-rt93-tegra #1 SMP PREEMPT RT Wed Jan 12 12:06:21 CST 2022 aarch64 aarch64 aarch64 GNU/Linux but when I cross compile my kernel module the modinfo is: vermagic: 4. As you say it is a If you are attempting to compile an OS kernel you will require a cross compiler as things such as the binary format will differ and you most likely won't want to include c headers for the compiler either (or you will want to use the headers from the OS you are targeting). The code of my LKM is the following: I cross compile a RPI3 32bit kernel from my x86 (ubuntu container on docker) and when tried to disable some variables (in my case e. Distributions such as Android, ChromeOS, CROSS_COMPILE is not used to prefix the Clang compiler binary (or corresponding LLVM utilities) as is the case for GNU utilities when LLVM=1 Meaning of some commands when cross-compiling kernel for Raspberry Pi. Linaro GCC. CF is often used on the command-line like this: linux-kernel; cross-compiling; autoconf; or ask your own question. Therefore, compiling the C library requires kernel headers, and many applications also require them. To do what you want though it's a little bit more difficult, install the cross compiler, get the same kernel version that you want the module to work with, copy the config from the target kernel, update the path to the compiler and I'll have to cross-compile on my laptop. The module I want to build is gadgetfs. the following would cross-compile for i686-w64-mingw32 : $ cat Makefile . Follow edited Jan 21, 2014 at 19:57. Define the Environment Variables. I use the cross-compiler “gcc-linaro-7. source that can be used by running source arm64_compile_env. Try to compile the tools, and if you have faced a concrete problem, then search for that problem, and if nothing helps, then ask on Stack Overflow. device driver) for a ARM Linux system. Linaro is a popular platform providing high-quality code for both Linux kernel and GCC tool chain. config which was used to compile the kernel. I will use this configuration as an example, but you can apply the same method for other environments. ARCH is the name of the architecture. Example: 7. Cross Compiling¶ A single Clang compiler binary (and corresponding LLVM utilities) will typically contain all supported back ends, which can help simplify cross compiling especially when Cross-compilation refers to the process of compiling code on one platform for execution on another platform. I must say that I am using the modified version of the riscv-tools of Ariane-SDK, but I didn't know anywhere else to ask for help, as I am really struggling with the creation of the Makefile for the cross-compile. Enter these commands to build an out-of-tree kernel module: $ cd <path_to_module_source> $ make ARCH=arm64 –C <kernel_directory> M=$(pwd) Cross Compiling Linux Arm Kernel with new driver module. CROSS_COMPILE is also used for ccache in some setups. Commented Apr 29, 2012 at 10:44. It can be convenient to setup environment variables for cross-compile in the current shell. How do I cross compile a single module? 4. Tells GCC to consider dir as the root of a tree that contains (a subset of) the root filesystem of the target operating system. o: Main. Cross compiling a kernel module ARM. sh -m sparc64 tools My current command to compile the kernel (which defaults to 64bit) is: obj-m += test. 3 Loading out-of-tree kernel modules; 7. This example is for RPI3. ko file to target and insert it. e. If you're adding a driver it's probably easiest to compile it in-tree. However, compiling with GCC 9. out: ozw-power-on-off. Target system. Coupled with emulation, testing Compiling it specifically for other architectures requires cross-compiling. But this tools cannot be reused when doing DKMS, this is simply because DKMS conflicts quitely with cross-compile. 2. Cross Compiling Linux Arm Kernel with new driver module. I will hack the broken cross-builded kernel manualy. Add a comment | 1 Answer Sorted by: Reset to The purpose of kernel headers is -->C library and compiled programs needs to interact with the kernel i. 05-x86_64_aarch64-linux-gnu”. Improve this question. Cross compile LKM module for Android platform. Make it executable: it is better to use latest kernel headers to compile libc but use --enable-kernel switch Build the cross-compiled C library (using the stage 1 cross compiler). Yes, just as you normally would for any other kind of module, KDIR needs to point to the built kernel source root. make file you can see the used defconfig, architecture, tool-chain and other cross compile specific rules. like --with-sysroot=${CLFS_CROSS_TOOLS}--with-sysroot--with-sysroot=dir. Best regards, Kemal Now I want to cross compile kernel modules for the OLinuXino board. Added file named arm64_compile_env. org. Consider a developer with an x86 laptop who wants to deploy a clever bug fix for an embedded device that uses an The buildworld step starts by building a cross-compiler and a few related tools. 15: 1384: July 1, 2023 tk1 - When you compile your kernel, mention the architecture you are compiling for in: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- EXTRAVERSION=-custom1 uImage I cross-compile some kernel modules, several modules is ok. kernel. Compiling Unix The Linux kernel has always traditionally been compiled with GNU toolchains such as GCC and binutils. Make it executable: $ chmod +x make We're done. This chapter examines the procedure for building your Raspbian kernel. how to compile Linux Kernel 4. I have a linux distribution of 64 bits, and the arm inside imx6 is based in 32 bits. CF is often used on the command-line like this: I use this command to recompile the kernel on xavier. In the procedure to follow, I assume that you have the SD card mounted on your cross-compile host file system. But there is one module I can’t compile successfully. The CPU architecture and cross-compiler prefix are defined through the ARCH and CROSS_COMPILE variables in the toplevel Makefile. makefile obj-m :=test. 7: 1601: October 18, 2021 How do I build a kernel on my Jetson Nano? Jetson Nano. It seems like you aren't really cross compiling but you have just replaced your compiler. On the RPI itself menuconfig showed those settings in "System Type" but this menu isnt even there. From Cross-compiling the kernel, see that they are not the same at all: The CPU architecture and cross-compiler prefix are defined through the ARCH and CROSS_COMPILE variables in the toplevel Makefile. 17 you don’t need to give CROSS_COMPILE= on the command line any longer, just run: make ARCH=parisc # to All I want to do is cross compile my kernel for the linux arm machine with a newly included driver (included in the config from make menuconfig). Installing a newly built kernel isn't that simple, especially if you're targetting a Raspberry Pi Compute Module board. --target gives the target system. This only works as long as the configuration doesn't differ too much. CROSS_COMPILE can be a part of the filename or the full path. Case sensitive file system. o A You have a mac? You need to compile linux kernel for your Raspberry PI? Great. 35-rt52 #1 SMP PREEMPT RT Wed Jun 12 09:57:26 CDT 2013 armv7l GNU/Linux I need to add Ethernet bonding driver kernel module , but got errors can you help me on Cross-compile value proposition 30+ architectures supported (several sub-archs) Native compile testing requires wide range of test systems – not practical Ability to cross-compile non-natively on an widely available architecture helps detect compile errors Coupled with emulation environments (e. This is called cross-compiling. A kernel sources package can be quickly emerged from the Gentoo ebuild Expanding on my previous blog post, which covered the basics of natively building a Linux kernel from scratch, we will now look at building a kernel for a different architecture. g. Now you can easily compile the Linux kernel with Clang/LLVM , a modern C-family compiler. To be built as a cross compiler gcc needs to be configured with --host=<host_os> and --target=<target_os where <host_os> is the platform the compiler will run on (windows in your case) and <target_os> is the platform you are targetting. For example, to cross-compile the arm64 kernel: You'll need to build using the same source tree as the existing kernel - including any patches. Compiling it specifically for other architectures requires cross-compiling. 4 Cross-compiling Linux from source; 7. Cross compilation for ARM board? 2. Because it used the same configuration file and the same version string the available modules should still load. k. 26 used ppc or powerpc, so I would try: make menuconfig ARCH=powerpc CROSS_COMPILE=ppc_xyz- As far as I know, there is no tutorial for doing that. To cross compile the kernel, you'll need two compilers: One that is able to build tools that run in your build environment, and one that can create executables for your target. The kernel tree is self-contained, so simply cross-compiling it in place will work. Despite this, cross-compiling on desktop systems is preferred for faster compile times. Jetson Nano. I followed the official RPI kernel build guide All I want to do is cross compile my kernel for the linux arm machine with a newly included driver (included in the config from make menuconfig). I have my toolchain installed. 9. For other platform just adjust ARCH, KERNEL, and CROSS_COMPILE envs. How to install cross-compiled linux modules to ARM board. Check it out. Linux kernel source directory; Output Files Produced. 4. 47 I am new at Linux kernel and I try to make a cross compile to build a driver for imx6, previusly I created the kernel using Yocto1. So i've downloaded the proper toolchain (uclibc mipsle toolchain) and i was successfull in compiling a simple working hello world that i've executed on my router where i have an ssh shell. The components that can be usually found on an SoC include a central processing unit (CPU), memory, input/output ports, A kernel sources package can be quickly emerged from the Gentoo ebuild repository or fetch the latest sources from kernel. 05-x86_64_aarch64-linux-gnu export "Paths and misc options" ---> Under "Build behavior", set "Number of parallel jobs" to 1. Here, we download GCC latest-6 binary under arm-linux-gnueabihf. I'm trying to cross compile a helloworld kernel module with specifications: host: intel x86 32 bit, linux-3. An Ubuntu 16. I followed this steps: Download sources from this on my host machine and unzip in /usrs/src I copied /proc/config. That shouldn't be a problem. 5: 1619: October 14, 2021 Kernel-4. That way I was able to specify the kernel headers build directory for cross compiling the kernel module and it worked. In this post, I will discuss how to successfully cross-compile any program for any architecture in the Linux What is cross compiling? Cross compilation is where the compiler produces executable for running on a different platform. gcc-stage-2: Build a full (stage 2) C cross-compiler; The source of the headers and libc will vary across platforms. Make sure you are ready to build the BSP by checking our Assumptions section. It always stop at ## B For reliability in serious applications, the disk image provider must also provide a compatible cross compiler. CROSS_COMPILE¶ Specify an optional fixed part of the binutils filename. The official documentation for the Linux For reliability in serious applications, the disk image provider must also provide a compatible cross compiler. /make Notes for cross-compiling. Follow me Part 1. You can cross compile the kernel modules by running a make linux command from the SDK's top directory. Cross compiling Linux ARM kernel modules 01 Dec 2017. Although you can install a cross compiler with apt conveniently, I must warn you that this is not necessarily reliable unless explicitly supported by the image provider. Debian automated cross-bootstrapping. Best regards, Kemal Make deb packages for kernel cd linux-source-4. This guide will allow you to cross-compile a loadable kernel module (LKM; a. : make ARCH=parisc CROSS_COMPILE=hppa64-linux-gnu- # to build a 32- or 64-bit kernel (depending on the value in the . " - On Stack Overflow we don't write guides and other tutorials. z from tx2 to my host machine (zcat CROSS_COMPILE¶ Specify an optional fixed part of the binutils filename. fllfgvc eewb zzb nxutx qrgkw mvsey dlbw dgcaed kmqj uxxf