Linux Lab

This project aims to make a Qemu-based Linux development Lab to easier the learning and development of the Linux Kernel.

A full Chinese document is added: Using Linux Lab to do embedded linux development.

For Linux 0.11, please try our Linux 0.11 Lab.

Homepage

See: http://tinylab.org/linux-lab/

Download the lab

$ git clone https://github.com/tinyclub/cloud-lab.git
$ cd cloud-lab/ && tools/docker/choose linux-lab

$ tools/docker/pull # Pull from docker hub

$ tools/docker/run

For Ubuntu 12.04, please install the new kernel at first, otherwise, docker will not work:

$ sudo apt-get install linux-generic-lts-trusty

Quickstart

Login the VNC page via tools/open-docker-lab.sh with the password printed in the console, and then open the 'Linux Lab' desktop shortcut on the desktop to launch into the Lab, and issue the following command to boot the prebuilt kernel and rootfs on the default versatilepb board:

$ make boot

Notes

If the screen size doesn't fit your display, set the scaling mode via the setting button on the top right side, or just modify the -screen 0 1720x960x16 of tools/supervisord.conf to your own. the second method need to rerun tools/install-docker-lab.sh and tools/run-docker-lab-daemon.h.

Usage

Check supported boards:

$ make list
[ pc ]:
      ARCH     = x86
      CPU     ?= i686
      LINUX   ?= 4.6
      ROOTDEV ?= /dev/ram0
[ g3beige ]:
      ARCH     = powerpc
      CPU     ?= generic
      LINUX   ?= 4.6
      ROOTDEV ?= /dev/ram0
[ vexpress-a9 ]:
      ARCH     = arm
      CPU     ?= cortex-a9
      LINUX   ?= 4.6
      ROOTDEV ?= /dev/mmcblk0
[ malta ]:
      ARCH     = mips
      CPU     ?= mips32r2
      LINUX   ?= 4.6
      ROOTDEV ?= /dev/ram0
[ versatilepb ]:
      ARCH     = arm
      CPU     ?= arm926t
      LINUX   ?= 4.6
      ROOTDEV ?= /dev/ram0

Check the board specific configuration:

$ cat boards/versatilepb/Makefile

Download the sources:

$ make core-source -j3     # All in one

$ make kernel-source       # One by one
$ make root-source

Checkout/Configure the sources:

$ make checkout         # Without uboot
$ make config           # Configure all with defconfig, without uboot

$ make kernel-checkout  # Checkout the specific version, *Please make sure changes are saved before do it!*
$ make kernel-defconfig # Configure one by one
$ make root-defconfig

$ make kernel-defconfig
$ make kernel-defconfig KP=0  # Disable kernel patch action

Manually configure the sources:

$ make kernel-menuconfig
$ make root-menuconfig

Build them:

$ make build   # All in one without uboot

$ make kernel  # One by one
$ make root

$ make kernel-modules # Build internel kernel modules, Must ensure CONFIG_MODULES=y
$ make kernel-modules-install
$ make root-rebuild && make boot

$ make kernel-modules LDT=1                # Compile examples/ldt/
$ make kernel-modules M=$PWD/examples/ldt  # With traditional methods

Boot it:

$ make boot     # Boot with graphic

$ make boot G=0  # Boot with serial port (no graphic), exit with 'CTRL+a x' or 'pkill qemu'

$ make boot PBK=0 PBD=0 PBR=0 # Disable prebuilt kernel, dtb and rootfs

$ make boot U=1  # Boot with Uboot

Boot with different rootfs:

$ make boot ROOTDEV=/dev/ram    # default
$ make boot ROOTDEV=/dev/nfs
$ make boot ROOTDEV=/dev/sda
$ make boot ROOTDEV=/dev/mmcblk0

Debug it:

Compile the kernel with `CONFIG_DEBUG_INFO=y` and debug it directly:

$ make BOARD=malta debug

Or debug it in two steps:

$ make BOARD=malta boot DEBUG=1

Open a new terminal:

$ make env | grep KERNEL_OUTPUT
/labs/linux-lab/output/mipsel/linux-4.6-malta/

$ mipsel-linux-gnu-gdb output/mipsel/linux-4.6-malta/vmlinux
(gdb) target remote :1234
(gdb) b kernel_entry
(gdb) b start_kernel
(gdb) b do_fork
(gdb) c
(gdb) c
(gdb) c
(gdb) bt

Note: some commands have been already added in `.gdbinit`, you can customize it for yourself.

Save your changes:

$ make save         # Save all of the configs and rootfs/kernel/dtb images

$ make kconfig-save # Save configs to boards/BOARD/, kernel config
$ make rconfig-save # rootfs config

$ make root-save    # Save images to prebuilt/
$ make kernel-save

If NFS boot fails, please make sure IP_PNP and ROOT_NFS are configured in kernel and if issue still exists, then try to fix up it:

$ /configs/tools/restart-net-servers.sh

By default, the default board: 'versatilepb' is used, we can configure, build and boot for a specific board with 'BOARD', for example:

$ make BOARD=malta
$ make root-defconfig
$ make root
$ make kernel-checkout
$ make kernel-defconfig
$ make kernel
$ make boot U=0

To transfer files between Qemu Board and Host, three methods are supported by default:

The first one is simply put the files with a relative path in system/

$ cd system/ $ mkdir system/root/ $ touch system/root/new_file $ make root-install $ make root-rebuild $ make boot G=1
Another is /dev/nfs, this need to boot the board with ROOTDEV=/dev/nfs

Boot/Qemu Board:
```
  $ make boot ROOTDEV=/dev/nfs
```
Host:
```
  $ make env | grep ROOTDIR
```
ROOTDIR = /linux-lab/prebuilt/root/mipsel/mips32r2/rootfs

The third one is use tftp server of host from the Qemu board with the tftp command.

Host:

  $ ifconfig br0
  inet addr:172.17.0.3  Bcast:172.17.255.255  Mask:255.255.0.0
  $ cd tftpboot/
  $ ls tftpboot
  kft.patch kft.log

Qemu Board:

  $ ls
  kft_data.log
  $ tftp -g -r kft.patch 172.17.0.3
  $ tftp -p -r kft.log -l kft_data.log 172.17.0.3

Note: while put file from Qemu board to host, must create an empty file in host firstly. Buggy?

The fourth one is using 9p virtio (tested on vexpress-a9 board)

Reconfigure the kernel with:

  CONFIG_NET_9P=y
  CONFIG_NET_9P_VIRTIO=y
  CONFIG_9P_FS=y

Docker host:

  $ modprobe 9pnet_virtio
  $ lsmod | grep 9p
  9pnet_virtio           17519  0
  9pnet                  72068  1 9pnet_virtio

Host:

  $ make BOARD=vexpress-a9

  $ make root-install PBR=1
  $ make root-rebuild PBR=1

  $ touch share/test     # Create a file in host

  $ make boot U=0 ROOTDEV=/dev/ram0 PBR=1 SHARE=1

Qemu Board:

  $ ls /hostshare/       # Access the file in guest
  test
  $ touch /hostshare/guest-test   # Create a file in guest

Buildroot has provided many examples about buildroot and kernel configuration:

buildroot: configs/qemu_ARCH_BOARD_defconfig
kernel: board/qemu/ARCH-BOARD/linux-VERSION.config

To start a new ARCH, BOARD and linux VERSION test, please based on it.

Note1: different qemu version uses different kernel VERSION, so, to find the suitable kernel version, we can checkout different git tags.

Note2: If nfs or tftpboot not work, please run modprobe nfsd in host side and restart the net services via /configs/tools/restart-net-servers.sh and please make sure not use tools/docker/trun.

AubrCool / linux-lab

Linux Lab

Homepage

Download the lab

Quickstart

Usage

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