diff --git a/README.md b/README.md
index 8d17ec350afc4bf3e63ef403cb0b16c1621f8370..a85f664f9375895b6ffd865777a049516d4020db 100644
--- a/README.md
+++ b/README.md
@@ -31,9 +31,18 @@ sudo resize2fs /dev/sdx2
 
 Building the images requires considerable disk space and CPU resources, it is generally only required if you want to contribute to the development of the system images.
 
-To start the process, use `./mkimage.sh`. To start over, execute `./cleanup.sh` to delete the existing userland and image.
+To create a system image for all platforms, run this:
 
-The resulting file is `reform-system.img`.
+    ./mkimage.sh
+
+To only create the image for a specific platform, choose one out of imx8mq,
+a311d and ls1028a like so:
+
+    ./mkimage.sh imx8mq
+
+The resulting file is named `reform-system-${PLATFORM}.img` where `${PLATFORM}`
+is the name of the platform the image was built for (one of imx8mq, a311d or
+ls1028a).
 
 ## License