gem5: how to get the gem5 linux

Author: cirosantilli

README.adoc

@@ -3480,7 +3480,7 @@ But https://github.com/qemu/qemu/blob/v2.12.0/docs/config/mach-virt-graphical.cf
 
 so maybe it is not possible?
 
-=== gem5 Graphic mode
+=== gem5 graphic mode
 
 gem5 does not have a "text mode", since it cannot redirect the Linux terminal to same host terminal where the executable is running: you are always forced to connect to the terminal with `gem-shell`.
 
@@ -3491,6 +3491,7 @@ Overview: https://stackoverflow.com/questions/50364863/how-to-get-graphical-gui-
 More concretely:
 
 ....
+git -C "$(./getvar linux_src_dir)" fetch https://gem5.googlesource.com/arm/linux gem5/v4.15:gem5/v4.15
 git -C "$(./getvar linux_src_dir)" checkout gem5/v4.15
 ./build-linux \
   --arch arm \