diff --git a/README.md b/README.md
index 657322b..61bbde7 100644
--- a/README.md
+++ b/README.md
@@ -1,11 +1,13 @@
-# Linux kernel for Raspberry Pi 32 bits, for usage in gokrazy
+# Kernel for Raspberry Pi 32 bits (in sync with official bullseye repo)
 
-Usage
+This repository holds a pre-built 32 bits Linux bits kernel image for the Raspberry Pi, compiled from https://github.com/raspberrypi/linux, for usage by the [gokrazy](https://github.com/gokrazy/gokrazy) project.
+
+To use the files in this repository, adjust the `-kernel_package`
+of `gokr-packer`:
 
 ```
-GOARCH=arm ./gokr-packer \
+GOARCH=arm gokr-packer \
     -kernel_package=github.com/oliverpool/kernel-rpi-os-32/dist \
-    -firmware_package=github.com/oliverpool/firmware-rpi/dist \
     github.com/gokrazy/hello
 ```
 
@@ -17,6 +19,14 @@ go run cmd/compile/main.go
 
 It will compile the kernel located in `linux-sources` and copy the resulting files in the `dist` folder.
 
+## Update check
+
+```
+go run cmd/check-update/main.go
+```
+
+It will compare the kernel version distributed on https://archive.raspberrypi.org/debian/ with the `linux-sources` submodule current HEAD.
+
 ## Licenses
 
 - The `vmlinuz` and `*.dtb` files are built from [Linux kernel sources](https://github.com/raspberrypi/linux), released under the GPL (see `linux-sources/COPYING`)