Linux in a Virtual Machine (QEMU) - HackMD (2023)

---tags: Linux Kernel---# Linux on Virtual Machine (QEMU)contributed by < Dung-Ru Tsai ># Ubuntu Image on [QEMU](https://www.qemu.org/download/)**1. Build and Install QEMU**```bash git clone https://gitlab.com/qemu-project/qemu.gitcd qemugit submodule initgit submodule update --recursivegit checkout v6.1.0mkdir buildcd build../configure --prefix=/usr/local/bin \ --enable-debug \ --enable-virtfsmake -j8sudo make install```:::success[Dependency](https://wiki.qemu.org/Hosts/Linux#Simple_build_and_test):```sudo apt-get install git libglib2.0-dev libfdt-dev libpixman-1-dev zlib1g-dev```:::**2. Bridge host network with TAP interface**> [Setting up Qemu with a tap interface](https://gist.github.com/extremecoders-re/e8fd8a67a515fee0c873dcafc81d811c)- Create a bridge interface on Host (by netplan)```bashvim /etc/netplan/01-network-manager-all.yaml===== copy start =====network: version: 2 renderer: networkd ethernets: eno1: dhcp4: false dhcp6: false bridges: br0: interfaces: [eno1] addresses: [192.168.100.4/24] gateway4: 192.168.100.254 mtu: 1500 nameservers: addresses: [8.8.8.8] parameters: stp: false forward-delay: 4 dhcp4: false dhcp6: true===== copy end =====sudo netplan apply```- Create tap0 interface[bridge network with tap](https://blog.elastocloud.org/2015/07/qemukvm-bridged-network-with-tap.html)```bash=sudo ip tuntap add dev tap0 mode tapsudo ip link set dev tap0 master br0sudo ip link set dev tap0 up```**3. Create Disk image**```shellqemu-img create -f qcow2 kvm-generic.qcow2 30G```**4. Install Ubuntu ISO**> [qemu ubuntu20.04](https://www.arthurkoziel.com/qemu-ubuntu-20-04/)> [qemu quick reference](https://www.notion.so/QEMU-11408fae00c74630914c044f815d8549)```bash=#!/bin/bashPREFIX=/home/jake/mount_1TB/gns3serverISO=${PREFIX}/ubuntu-20.04.3-live-server-amd64.iso # Installation mediaNET=br0 # bridge nameOS=linux # os typeVM_DISK=${PREFIX}/kvm-generic.qcow2 # VM image on disksudo qemu-system-x86_64 \ -machine type=q35,accel=hvf \ -smp 2 \ -hda ${VM_DISK}\ -cdrom ${ISO} \ -m 4096 \ -vga virtio \ -usb \ -device usb-tablet \ -enable-kvm \ -cpu host \ -display default \ -boot d \ -netdev tap,id=mynet0,ifname=tap0,script=no,downscript=no \ -device e1000,netdev=mynet0,mac=52:55:00:d1:55:01```:::successQEMU Parameter help`qemu-system-x86_64 -accel ?``qemu-system-x86_64 -netdev ?`:::- Connect to VNC: `127.0.0.1:5900` **5. Running the system**```bash#!/bin/bashPREFIX=/home/jake/mount_1TB/gns3serverNET=br0 # bridge nameOS=linux # os typeVM_DISK=${PREFIX}/kvm-generic.qcow2 # VM image on disksudo ip tuntap add dev tap0 mode tapsudo ip link set dev tap0 master br0sudo ip link set dev tap0 upsudo qemu-system-x86_64 \ -machine type=q35,accel=hvf \ -smp 4 \ -hda ${VM_DISK}\ -m 4096 \ -vga virtio \ -usb \ -device usb-tablet \ -enable-kvm \ -cpu host \ -netdev tap,id=mynet0,ifname=tap0,script=no,downscript=no \ -device e1000,netdev=mynet0,mac=52:55:00:d1:55:01 \ -serial telnet:127.0.0.1:4322,server,nowait \ -display default -nographic```[Another example](https://gist.github.com/dungru/bf11265caf466d5a82672f3e984c8be9)**6. Redirect GRUB output to serial console (optional)**> [SerialConsoleHowto](https://help.ubuntu.com/community/SerialConsoleHowto)- Connect to VNC- Edit the `/etc/default/grub`, redirect serial message to ttyS0```bash=# If you change this file, run 'update-grub' afterwards to update# /boot/grub/grub.cfg. GRUB_DEFAULT=0GRUB_TIMEOUT=1GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200n8" # Uncomment to disable graphical terminal (grub-pc only)GRUB_TERMINAL=serialGRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"...```- Update the GRUB```bashsudo update-grubreboot# Open another terminaltelnet 127.0.0.1 4322```**7. Connect with ssh**```ssh dutsai@your-vm-ip```- [Install/running scripts](https://gist.github.com/dungru/96f4dd9f7a69c6baae1c77425f5a25af)# Enlarge the disk on VMhttps://www.linuxtechi.com/extend-lvm-partitions/https://www.tecmint.com/extend-and-reduce-lvms-in-linux/- Add new the partition```shell=qemu-img resize kvm-generic.qcow2 +60Gsudo fdisk -lsudo fdisk -cu /dev/sdaTo Create new partition Press n.Change the type using t.Type 8e to change the partition type to Linux LVM.Press w to write the changes.sudo sudo fdisk -l #check ```- Add new physical volume and add to volume group```shell=# Add physical volumesudo pvcreate /dev/sda4$ sudo pvs PV VG Fmt Attr PSize PFree /dev/sda3 ubuntu-vg lvm2 a-- <29.00g 0 /dev/sda4 ubuntu-vg lvm2 a-- 29.26g 0# Extend Volume Groupsudo vgextend ubuntu-vg /dev/sda4$ sudo vgs # check volume VG #PV #LV #SN Attr VSize VFree ubuntu-vg 1 1 0 wz--n- <29.00g <9.00g```- Resize Logical Volume```shell=# Get LV Pathsudo lvdisplay # Do it$ sudo lvextend /dev/ubuntu-vg/ubuntu-lv -l+100%FREE$ sudo resize2fs -p /dev/ubuntu-vg/ubuntu-lv$ df -h /Filesystem Size Used Avail Use% Mounted on/dev/mapper/ubuntu--vg-ubuntu--lv 28G 19G 8.1G 70% /```-------< obsoleted ># ARM64 QEMU Environment Setting## Method01: buildroot### 1. Set up the QEMU for aarch64```shell=wget https://download.qemu.org/qemu-2.12.1.tar.xztar xvJf qemu-2.12.1.tar.xzcd qemu-2.12.1./configure --target-list=aarch64-softmmu# Work with VirtIO + 9Psudo apt-get install libcap-dev libattr1-dev./configure --enable-virtfs --target-list=aarch64-softmmumake````--enable-virtfs` : 使得 VirtIO + 9P 可以運作，`--target-list` : 只產生可以運行 aarch64 架構的 qemu耐心等待一段時間之後，在 `aarch64-softmmu` 目錄下可以找到`qemu-system-aarch64`- Install the binary qemu-system-aarch64 to /usr/bin/```shell#$ sudo cp qemu-2.12.1/aarch64-softmmu/qemu-system-aarch64 /usr/binsudo make install```:::infoBuildroot Guide- 第3章 行程(process)環境:https://hackmd.io/s/rJf1ONuye - from link: [Taiwan linux study group](https://hackmd.io/KYRgLADAZgJgzFAtAQwBxwKyLHYrEBGAbBmIsBARGAQJxgDGUlQA):::### 2. Build AArch64 image with buildroot```shell=$ sudo apt-get install libncurses-dev$ git clone https://github.com/buildroot/buildroot$ make list-defconfigs# Generate the .config$ make qemu_aarch64_virt_defconfig$ make menuconfig# 使用Kernel 5.0 header$ make linux-menuconfig# 開啟 9P File System$ make```- [設定Kernel 5.0 教學](https://hackmd.io/s/ryQIj1MKV#%E8%AA%BF%E6%95%B4%E8%87%B3-Linux-50x)- 9P File System9P File System [設定教學](https://wiki.qemu.org/Documentation/9psetup)### 3. Run the emulation Qemu```shell=$ qemu-system-aarch64 -M virt \-cpu cortex-a53 \-nographic -smp 1 \-kernel output/images/Image \-append "root=/dev/vda console=ttyAMA0" \-netdev user,id=eth0 -device virtio-net-device,netdev=eth0 \-drive file=output/images/rootfs.ext4,if=none,format=raw,id=hd0 \-device virtio-blk-device,drive=hd0 \-fsdev local,security_model=passthrough,id=fsdev0,path=/tmp \-device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=host_mount```注意最後兩行 `-fsdev` and `-device`, 是為了掛載 host 的目錄才有的### 4. 掛載 host 的目錄```shell=mkdir sharemount -t 9p -o trans=virtio host_mount share -oversion=9p2000.L```Reference: [0xff07](https://hackmd.io/s/ryQIj1MKV#2019q1-Homework4-smallsys)[9psetup](https://wiki.qemu.org/Documentation/9psetup)## Method-02: Kernel source### 1. Set up the QEMU for aarch64```shell=wget https://download.qemu.org/qemu-2.12.1.tar.xztar xvJf qemu-2.12.1.tar.xzcd qemu-2.12.1./configure --target-list=aarch64-softmmu# Work with VirtIO + 9Psudo apt-get install libcap-dev libattr1-dev./configure --enable-virtfs --target-list=aarch64-softmmumake````--enable-virtfs` : 使得 VirtIO + 9P 可以運作，`--target-list` : 只產生可以運行 aarch64 架構的 qemu耐心等待一段時間之後，在 `aarch64-softmmu` 目錄下可以找到`qemu-system-aarch64`- Install the binary qemu-system-aarch64 to /usr/bin/```shell$ sudo cp qemu-2.12.1/aarch64-softmmu/qemu-system-aarch64 /usr/binsudo make install```### 2. Create initramfs cpio (Create the file system)```shell$ git clone https://github.com/buildroot/buildroot$ make list-defconfigs$ make qemu_aarch64_virt_defconfig$ make menuconfig```- Target options —> Target Architecture: 選擇 AArch64 little-endian- Toolcahin —> Toolchain type: 選擇 External toolchainToolchain: 選擇 Linaro AArch64 2018.05- System configuration —> Run a getty (login prompt) after bootTTY port 改為 ttyAMA0- Filesystem images —> cpio the root filesystem (for use as an initial RAM filesystem)儲存之後，進行 make。若無異常，可以在 output/images 目錄底下找到 **rootfs.cpio**### 3. Build aarch64 Kernel from source:::infoKernel Source code - [Linux Kernel]( https://www.kernel.org/pub/linux/kernel/ ) - [Preempty Kernel patch]( https://www.kernel.org/pub/linux/kernel/projects/rt/) - [Building the preeempty kernel on ubuntu](https://ubuntuforums.org/showthread.php?t=2273355):::```shell=git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux-stablecd linux-stablesudo apt-get install gcc-aarch64-linux-gnumake ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfigmake ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig```Edit the .config for 9P```shell=CONFIG_CMDLINE="console-ttyAMA0"# points at your buildrootimageCONFIG_INITRAMFS_SOURCE="/home/jake/QEMU/rootfs.cpio" # needed for virtfs mountCONFIG_NET_9P=y CONFIG_NET_9P_VIRTIO=y```一切就緒就開始編譯核心```shell=## Build the Kernelmake ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-```The image path will show at `arch/arm64/boot/Image` or linux/vmlinux### 4. Run the emulation QEMU```shell=#!/bin/bashqemu-system-aarch64 \-machine virt \-machine type=virt \-cpu cortex-a57 \-nographic -smp 1 \-m 8192 \-kernel /home/jake/QEMU/linux-stable/arch/arm64/boot/Image \--append "console=ttyAMA0" \-fsdev local,security_model=passthrough,id=test_dev,path=/home/jake/Workspace/ -device virtio-9p-pci,id=fsdev0,fsdev=test_dev,mount_tag=host_mount ```- `-kernel` : 指定第二步驟編譯好的 image path- `-fsdev, path` : 指定共享目錄的路徑 - path 是在 host 這邊要目錄分享的路徑，這邊是用 `/home/jake/Workspace/` - 而最後面那個 `mount_tag=host_mount` 是到時候在 guest 裡面 mount 時會用到.### 5. 掛載 host 的目錄透過 VirtIO + 9P 使得 guest 與 host 共享目錄:`mount -t 9p -o trans=virtio host_mount /mnt`- Exit the QEMU:Ctrl+a X#### Reference- Video: [Starting Linux kernel exploration with Eukabuka](https://www.youtube.com/watch?v=zK2Agg3U2cU)- QEMU Source :https://www.qemu.org/download/#source- [Running Linux in QEMU’s aarch64 system emulation mode](https://www.bennee.com/~alex/blog/2014/05/09/running-linux-in-qemus-aarch64-system-emulation-mode/)- [atlantis0914](https://hackmd.io/s/HJb80Rdt4#2019q1-Homework4-smallsys)# X86_64 QEMU Environment Setting [PASS]## Method-01 buildroot source### 1. Build the QEMU```shellwget https://download.qemu.org/qemu-4.2.0.tar.xztar xvJf qemu-4.2.0.tar.xzcd qemu-4.2.0# Work with VirtIO + 9Psudo apt-get install libcap-dev libattr1-devsudo apt install build-essential kernel-package fakeroot libncurses5-dev libssl-dev ccache flex bison libelf-devsudo apt-get install libglib2.0-dev libfdt-dev libpixman-1-dev zlib1g-dev install libnfs-dev libiscsi-dev./configure --enable-virtfs --target-list=x86_64-softmmu --enable-debugmake -j8... wait for a whilesudo make install````--enable-virtfs`: Enable the virtual file IO system### 2. Build the Linux from buildrootCheck the basic build guide in`cat README````shellmake list-defconfigsmake qemu_x86_64_defconfigmake# find the kernel, bootloader, root filesystem, etc. in output/images```### 3. Run the qemu with LinuxCheck the qemu startup guide`cat board/qemu/x86_64/readme.txt````shellqemu-system-x86_64 -M pc \ -kernel output/images/bzImage \ -drive file=output/images/rootfs.ext2,if=virtio,format=raw \ -append "rootwait root=/dev/vda console=tty1 console=ttyS0" \ -serial stdio \ -net nic,model=virtio \ -net user# Optionally add -smp N to emulate a SMP system with N CPUs.```:::success```shelludhcpc: sending select for 10.0.2.15udhcpc: lease of 10.0.2.15 obtained, lease time 86400deleting routersrandom: mktemp: uninitialized urandom read (6 bytes read)adding dns 10.0.2.3OKWelcome to Buildrootbuildroot login: root```:::## Method-02 Kernel Source### 1. Build the QEMU```shellsudo apt update -ysudo apt install libcap-ng-dev libattr1-dev build-essential kernel-package fakeroot libncurses5-dev libssl-dev ccache flex bison libelf-dev libglib2.0-dev libfdt-dev libpixman-1-dev zlib1g-dev libnfs-dev libiscsi-dev ninja-buildwget https://download.qemu.org/qemu-6.2.0.tar.xztar xvJf qemu-6.2.0.tar.xzcd qemu-6.2.0./configure --enable-virtfs --target-list=x86_64-softmmu --enable-debugmake -j8... wait for a whilesudo make install````--enable-virtfs`: Enable the virtual file IO system### 2.1 Create the root file system```shell$ git clone https://github.com/buildroot/buildroot$ make list-defconfigs$ make qemu_x86_64_defconfig$ make menuconfig```- Target options —> Target Architecture: 選擇 x86_64- Filesystem images —> ext2/3/4 root file system:::infocpio the root filesystem (for use as an initial RAM filesystem) :::儲存之後，進行 make。若無異常，可以在 output/images 目錄底下找到 **rootfs.cpio**### 2.2 Build Kernel from linux source- [Prepare the environment for developing Linux kernel with qemu](https://medium.com/@daeseok.youn/prepare-the-environment-for-developing-linux-kernel-with-qemu-c55e37ba8ade)- https://mirrors.edge.kernel.org/pub/linux/kernel/```bash=make ARCH=x86_64 x86_64_defconfig make ARCH=x86_64 menuconfigmake -j8```- Kernel hacking -> Compile the kernel with debug info -> Provide GDB scripts for kernel debugging- `Reduce debugging information` option off- Force unload the kernel module: `MODULE_FORCE_UNLOAD`- KGDB```shellCONFIG_DEBUG_INFO=yCONFIG_FRAME_POINTER=yCONFIG_HAVE_ARCH_KGDB=yCONFIG_KGDB=yCONFIG_KGDB_SERIAL_CONSOLE=y```- Ensure the following 9P options are enabled in the kernel configuration.```shell CONFIG_NET_9P=y CONFIG_NET_9P_VIRTIO=y CONFIG_NET_9P_DEBUG=y (Optional) CONFIG_9P_FS=y CONFIG_9P_FS_POSIX_ACL=y CONFIG_PCI=y CONFIG_VIRTIO_PCI=y CONFIG_PCI_HOST_GENERIC=y (only needed for the QEMU Arm 'virt' board)```The final image will show in `arch/x86/boot/bzImage`.- ramfile system only```# Only for ramfile system when you choose in builtroot Filesystem images is cpio:CONFIG_INITRAMFS_SOURCE="/home/jake/QEMU/rootfs.cpio"```### 3.1 Run qemu with own Linux Kernel (No File system)```shellqemu-system-x86_64 -s -S\-kernel arch/x86/boot/bzImage \-hda /dev/zero \-append "root=/dev/zero console=ttyS0" \-serial stdio -display none```Try the KGDB```shellcd linuxgdb ./vmlinux(gdb) target remote localhost:1234(gdb) break start_kernel(gdb) cContinuing.Breakpoint 1, start_kernel () at init/main.c:786786{```### 3.2 Run qemu with own Linux Kernel with Files system```bashqemu-system-x86_64 -kernel arch/x86/boot/bzImage \-boot c -m 2049M \-append "root=/dev/sda rw console=ttyS0,115200 acpi=off nokaslr" \-hda output/images/rootfs.ext4 \-fsdev local,security_model=passthrough,id=fsdev0,path=/home/dutsai/Workspace_vm \-device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=host_mount \-nographic \-monitor telnet::45454,server,nowait \-serial mon:stdio```- `-kernel` : 指定第二步驟編譯好的 image path- `-fsdev, path` : 指定共享目錄的路徑 - path 是在 host 這邊要目錄分享的路徑，這邊用 `/home/dutsai/Workspace_vm` - `mount_tag=host_mount` 在 guest 裡面 mount 時會用.- `-serial mon:stdio` Send Ctrl+C to guest - `Ctrl+a X` to exit qemu.### 4. Mount host folderhttps://wiki.qemu.org/Documentation/9psetup```bash=# In qemumount -t 9p -o trans=virtio host_mount /root -oversion=9p2000.L```### 5. KGDB```shellqemu-system-x86_64 \-kernel linux-5.16.14/arch/x86/boot/bzImage \-boot c -m 4096M \-append "root=/dev/sda rw console=ttyS0,115200 acpi=off nokaslr" \-hda buildroot/output/images/rootfs.ext4 \-fsdev local,security_model=passthrough,id=fsdev0,path=/home/dutsai/Workspace_vm \-device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=host_mount \-nographic \-monitor telnet::45454,server,nowait \-serial mon:stdio \-S -gdb tcp::33004```Try to open another terminal to run gdb.```shellcd linuxgdb ./vmlinux(gdb) target remote localhost:33004(gdb) break start_kernel(gdb) cContinuing.Breakpoint 1, start_kernel () at init/main.c:786786{```## Method-03 Ycoto[RISC-V Embedded Linux - Get started with Buildroot/Yocto](https://hackmd.io/@coscup/SJLHICJTc/%2F%40coscup%2FSkfNICy69)# Update Linux Kernel:::infoKernel Source code - [Linux Kernel]( https://www.kernel.org/pub/linux/kernel/ ) - [Preempty Kernel patch]( https://www.kernel.org/pub/linux/kernel/projects/rt/) - [Building the preeempty kernel on ubuntu](https://ubuntuforums.org/showthread.php?t=2273355):::- Get from Newest [release](https://github.com/torvalds/linux/tags)- [Ubuntu 22.04 is Jammy Jellyfish](https://code.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/jammy)- [將 memchr() 放入核心並重新 compile](https://hackmd.io/@arthur-chang/linux2022-quiz8?fbclid=IwAR3TsBYPmvISIC7xcYQ8s2uPZo9aWk7vm8DZqHwMdggfH5PVUKcUgnAJfCs#%E5%B0%87-memchr-%E6%94%BE%E5%85%A5%E6%A0%B8%E5%BF%83%E4%B8%A6%E9%87%8D%E6%96%B0-compile)Source code: https://www.kernel.org/```shell=$ sudo apt-get install liblz4-tool libc6-dev libncurses5-dev openssl wget ca-certificates bc libzstd-dev zstd$ sudo apt-get install git fakeroot build-essential ncurses-dev xz-utils libssl-dev bc flex libelf-dev bison dwarves$ wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.17.9.tar.xz$ cp /boot/config-`uname -r` .config$ make menuconfig選擇 load 再選擇 save# make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig$ scripts/config --disable SYSTEM_TRUSTED_KEYS$ scripts/config --disable SYSTEM_REVOCATION_KEYSCONFIG_DEBUG_INFO_BTF=n# Build$ make -j12$ make modules -j12# Install$ sudo make INSTALL_MOD_STRIP=1 modules_install -j 4$ sudo make install$ sudo mkinitramfs /lib/modules/5.17.9/ -o /boot/initrd.img-5.17.9$ sudo update-grub2# Install Method2$ su -c "make modules_install install"```# Patch RT (Linux)- Install the ubuntu 16.04- [Building and Install the preeempt kernel on Ubuntu](https://ubuntuforums.org/showthread.php?t=2273355)- Kernel Version https://www.kernel.org/pub/linux/kernel/ - linux-4.4.60- Preempt RT Version https://www.kernel.org/pub/linux/kernel/projects/rt/ - patch-4.4.60-rt73 (Linux preempt RT 4.4.60-rt73+) - https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/4.4/older/patch-4.4.60-rt73.patch.gz- [Linux RT Kernel config](https://gist.github.com/ldotrg/c69d0ee45ab28884d26c9ba8fc275e70) replace the `.config` file - Must turn off **Check for stack overflows** - `sudo apt-get install libssl-dev`### build kernel command```shell=$ sudo apt-get update$ sudo apt-get install build-essential linux-tools-common linux-tools-generic cmake automake libtool libusb-1.0-0-dev openssh-server samba vim linux-headers-`uname -r` can-utils libpopt-dev$ mkdir -p kernel$cd kernel# Download the kernel linux-4.4.60.tar.gz and patch-4.4.60-rt73.patch.gz $ wget https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/linux-4.4.60.tar.gz$ wget https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/4.4/older/patch-4.4.60-rt73.patch.gz$ tar -xzvf linux-4.4.60.tar.gz$ cd linux-4.4.60$ gzip -cd ../patch-4.4.60-rt73.patch.gz | patch -p1 --verbose$ sudo apt-get install libncurses-dev libssl-dev# Change .config file$ make menuconfig##Graphical Menu### Processor type and features ---> [Enter]# Preemption Model (Voluntary Kernel Preemption (Desktop)) [Enter]# Fully Preemptible Kernel (RT) [Enter] #Select# [Esc][Esc]# <Save> [Enter]/*# Kernel hacking --> [Enter]# Memory Debugging [Enter]# Check for stack overflows #Already deselected - do not select# [Esc][Esc]# [Right Arrow][Right Arrow]# .config# <Okay> [Enter]# <Exit> [Enter]# [Esc][Esc]# [Right Arrow]# <Exit> [Enter]*/makesudo make modules_install -j3sudo make install -j3 ```:::danger- [Linux RT Kernel .config simple](https://gist.github.com/ldotrg/c69d0ee45ab28884d26c9ba8fc275e70) replace the `.config` file in Linux-4.4.60- [EGSE .config full](https://gist.github.com/ldotrg/1ca2213f8c8569f59f4169a5ac4eab71):::**After install the kernel**- Verify and update. Verify that `initrd.img-4.4.60-rt73`, `vmlinuz-4.4.60-rt73`, and `config-4.4.60-rt73` exist. They should have been created in the previous step. ```shell$cd /boot$ ls```### Set the default kernel**1. Go to see the menuentry in** ```shellvim /boot/grub/grub.cfg```search your menuentry version and copy it.```menuentry 'Ubuntu, with Linux 4.4.60-rt73'```2. **sudo vim /etc/default/grub**```shell=$ sudo vim /etc/default/grub GRUB_DEFAULT='Advanced options for Ubuntu>Ubuntu, with Linux 4.4.60-rt73' GRUB_CMDLINE_LINUX_DEFAULT="isolcpus=1"```:::dangerCPU Isolation```shell=sudo vim /etc/default/grub ===> add GRUB_CMDLINE_LINUX_DEFAULT="isolcpus=1"sudo update-grubsudo reboot# Loogin Permissionsudo vim /etc/ssh/sshd_config ===> modify "PermitRootLogin yes"```:::3. **sudo update-grub** - it will show the error message, please change the GRUB_DEFAULT by use the correct one on error message.4. In BIOS, Turn off Hyper threading# Lima macOS1st Start```limactl start --name=default template://ubuntu-ltslimactl shell default```https://github.com/lima-vm/lima```sudo apt-get install sshfs build-essential linux-tools-common linux-tools-generic automake* linux-headers-`uname -r` net-tools wireless-tools```[linux-image-5.4.0-109-generic_5.4.0-109.123_arm64.deb](https://ubuntu.pkgs.org/20.04/ubuntu-proposed-main-arm64/linux-image-5.4.0-109-generic_5.4.0-109.123_arm64.deb.html)```sudo apt install linux-modules-extra-`uname -r````- YAML file on mac: ```vim /Users/dutsai/.lima/default# Ubuntu 20.04 LTS (Focal Fossa)# This example requires Lima v0.7.0 or later.images:# Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.- location: "https://cloud-images.ubuntu.com/releases/20.04/release-20220302/ubuntu-20.04-server-cloudimg-amd64.img" arch: "x86_64" digest: "sha256:243157ea0390890d6e60ce5e08e0249b16e23b6b313b63aed50f39f92b020afe"- location: "https://cloud-images.ubuntu.com/releases/20.04/release-20220302/ubuntu-20.04-server-cloudimg-arm64.img" arch: "aarch64" digest: "sha256:fb2b4efdbf0011bd2a9fd49e9d31efdd252966c889f07b5d246351ec5734a329"# Fallback to the latest release image.# Hint: run `limactl prune` to invalidate the cache- location: "https://cloud-images.ubuntu.com/releases/20.04/release/ubuntu-20.04-server-cloudimg-amd64.img" arch: "x86_64"- location: "https://cloud-images.ubuntu.com/releases/20.04/release/ubuntu-20.04-server-cloudimg-arm64.img" arch: "aarch64"mounts:- location: "~"- location: "~/Workspace_mac/vwifi" writable: true- location: "/tmp/lima" writable: true```# User mode Linuxhttps://hackmd.io/@sysprog/user-mode-linux-env```shell$ sudo apt install build-essential libncurses-dev flex bison$ sudo apt install xz-utils wget ca-certificates bc fakeroot$ wget https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.12.tar.xz$ tar xvf linux-5.12.tar.xz$ make mrproper$ make defconfig ARCH=um SUBARCH=x86_64$ make linux ARCH=um SUBARCH=x86_64 -j `nproc````- Root file system```shell$ export REPO=http://dl-cdn.alpinelinux.org/alpine/v3.13/main$ mkdir -p rootfs$ curl $REPO/x86_64/APKINDEX.tar.gz | tar -xz -C /tmp/$ export APK_TOOL=`grep -A1 apk-tools-static /tmp/APKINDEX | cut -c3- | xargs printf "%s-%s.apk"`$ curl $REPO/x86_64/$APK_TOOL | fakeroot tar -xz -C rootfs$ fakeroot rootfs/sbin/apk.static \ --repository $REPO --update-cache \ --allow-untrusted \ --root $PWD/rootfs --initdb add alpine-base$ echo $REPO > rootfs/etc/apk/repositories$ echo "LABEL=ALPINE_ROOT / auto defaults 1 1" >> rootfs/etc/fstab```- UML.sh``````[howto-usermode-linux](https://xeiaso.net/blog/howto-usermode-linux-2019-07-07)### Original Assignment info: [F08: smallsys](https://hackmd.io/s/BkhVVlHu4#F08-smallsys)