qscuio/ulk

Linux Development Learning

A linux kernel basic function test script.

Step 1

. ./ulk kernel=6.9.6

Note that qemu is started with -S flags, so the system will continue bootup only when gdb is connected and run continue command.

Step 2

. ./scripts/gdb

Step 3 (password qwert)

Do not use root, we mount current directory to /home/qwert/ ...

ssh [email protected]
ssh [email protected]

How To ssh

. ./scripts/connect

How to open Qemu monitor

. ./scripts/monitor

 vim .config
 CONFIG_KCOV=y
 CONFIG_DEBUG_INFO=y
 CONFIG_KASAN=y
 CONFIG_KASAN_INLINE=y
 CONFIG_CONFIGFS_FS=y
 CONFIG_SECURITYFS=y
 # CONFIG_RANDOMIZE_BASE is not set
 make savedefconfig

How To Install New package

rm -rf $RELEASE.id_rsa.pub
. ./ulk
. ./scripts/gdb

How to disable gdb by default

Remove -S flags from qemu

How to debug debootstrap does not work issue.

Check "chroot/debootstrap/debootstrap.log"

rm -rf $RELEASE.id_rsa*
sudo rm -rf chroot/{bin,sbin,lib,lib32,lib64,libx32,etc,usr,tmp,sys,srv,dev,mnt,proc,opt,run,home,boot}

How to build crash

Crash should be compiled after login to guest os.

Our current directory is mapped into /home/qwert.

cd crash && make && make install

It is really too slow to build crash in guest. So we keep a prebuild version in bins/$ARCH/crash

How to run arm64 app with qemu

qemu-aarch64-static -L /usr/aarch64-linux-gnu/ ./main

With -L option we can change the library search path for app run in qemu. This will fix the lib* cannot find issue.