Redirect output to the VM's serial port.

Makefile

@@ -4,7 +4,7 @@ tmp_image := $(shell echo $$$$)
 all: hello.tar hello.sizes vm-image to-be-run-in-vm.sh Makefile
 	qemu-img create -f qcow2 -o backing_file=vm-image vm-image-tmp-${tmp_image}
 # TODO: qcow2: make a derived image.
-	qemu-system-x86_64 -enable-kvm -m 256 \
+	qemu-system-x86_64 -enable-kvm -m 256 -nographic \
 	  vm-image-tmp-${tmp_image} \
 	  -drive format=raw,file=hello.sizes,if=ide,index=1,media=disk \
 	  -drive format=raw,file=to-be-run-in-vm.sh,if=ide,index=2,media=disk \

config.scm

@@ -18,7 +18,9 @@
  (bootloader
   (bootloader-configuration
    (bootloader grub-bootloader)
-   (target "/dev/sdX")))
+   (target "/dev/sdX")
+   (timeout 1)))
+ (kernel-arguments '("console=ttyS0"))
  (host-name "hostname")
  (file-systems
   (cons (file-system