Add QEMUEXTRA environment to add extra QEMU arguments, like in JOS

diff --git a/Makefile b/Makefile
index e259619fd12f8e69c774ecdf5e456dd075346339..b13ab4d09752a8df6319f7a21b7f5c1b8a5b573d 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -201,7 +201,7 @@ QEMUGDB = $(shell if $(QEMU) -help | grep -q '^-gdb'; \
 ifndef CPUS
 CPUS := 2
 endif
-QEMUOPTS = -hdb fs.img xv6.img -smp $(CPUS) -m 512
+QEMUOPTS = -hdb fs.img xv6.img -smp $(CPUS) -m 512 $(QEMUEXTRA)
 
 qemu: fs.img xv6.img
        $(QEMU) -serial mon:stdio $(QEMUOPTS)