stap-onboot - Man Page

stap-onboot [Options] [SCRIPT...]

The stap-onboot command compiles SystemTap scripts and uses dracut to embed them into an initramfs, allowing the scripts to run during early boot before the root filesystem is mounted. This is useful for debugging early-boot issues or applying CVE band-aid scripts that need to run as early as possible.

Scripts are read from /etc/systemtap/script.d/. Compiled modules are cached in /var/cache/systemtap/KERNEL/.

-b

Backup the existing initramfs before overwriting it. The backup is saved with a .bak extension.

-c configfile

Specify an alternate configuration file instead of the default /etc/systemtap/config.

-o path.img

Specify the output initramfs file path. By default, the initramfs for the current kernel is updated at /boot/initramfs-KERNEL.img.

-r kernelrelease

Specify the kernel release to build the initramfs for. Defaults to the currently running kernel (uname -r).

SCRIPT

One or more script names (without the .stp extension) to compile and embed in the initramfs. Scripts must exist in /etc/systemtap/script.d/. If no scripts are specified, a clean initramfs without SystemTap scripts is created.

Compile and embed myScript.stp into the initramfs, backing up the original: # stap-onboot -b myScript

Create an initramfs for a different kernel: # stap-onboot -r 6.1.0-1.fc37.x86_64 earlyDebug

Create a custom initramfs in a specific location: # stap-onboot -o /tmp/test-initramfs.img bandaid

Remove all SystemTap scripts from the initramfs: # stap-onboot

/etc/systemtap/script.d/SCRIPT.stp

Source SystemTap scripts to be embedded.

/etc/systemtap/config

Configuration file for script options. Each script can have options defined as SCRIPTNAME_OPT=....

/var/cache/systemtap/KERNEL/

Directory where compiled .ko modules are cached.

/boot/initramfs-KERNEL.img

Default output location for the generated initramfs.

/usr/lib/dracut/modules.d/99stap

Dracut module directory for SystemTap integration.

stap(1), staprun(8), dracut(8), systemd.service(5)