diff --git a/README.adoc b/README.adoc
index aaee759..cfc9799 100644
--- a/README.adoc
+++ b/README.adoc
@@ -1506,6 +1506,8 @@ Tested architectures:
 * `aarch64`
 * `x86_64`
 
+Like QEMU, gem5 also has a syscall emulation mode (SE), but in this tutorial we focus on the full system emulation mode (FS). For a comparision see: https://stackoverflow.com/questions/48986597/when-should-you-use-full-system-fs-vs-syscall-emulation-se-with-userland-program
+
 === gem5 vs QEMU
 
 * advantages of gem5: