Merge ~rafaelfolco/cirros:ppc_console into cirros:master

[Rafael Folco]

Enable console during kernel boot on Power

On Power systems console should be added the kernel command line
in the following order: 'console=tty0 console=hvc0'.
The first one is the graphical console. The last one is the serial
console. The kernel enables all the consoles pointed through the
kernel command line. However, only the last one will receive
input/output during kernel boot. All the other consoles will be
enabled after the boot.

This is required for QCOW2 images now used by default in DevStack.

[Robin H. Johnson (robbat2)]

+1 on this change, but note that which console is chosen in QEMU without this patch depends on availability of VGA & USB input.

review: Approve

Unmerged commits

8ccdc1c... by Rafael Folco on 2017-07-07

Enable console during kernel boot on Power

On Power systems console should be added the kernel command line
in the following order: 'console=tty0 console=hvc0'.
The first one is the graphical console. The last one is the serial
console. The kernel enables all the consoles pointed through the
kernel command line. However, only the last one will receive
input/output during kernel boot. All the other consoles will be
enabled after the boot.

diff --git a/bin/part2disk b/bin/part2disk
index e2dae8c..4a1d543 100755
--- a/bin/part2disk
+++ b/bin/part2disk
@@ -264,7 +264,7 @@ menuentry 'CirrOS' {
           search --no-floppy --label --set=root cirros-rootfs
         fi
 
-    linux  /boot/${kernelfile} LABEL=cirros-rootfs ro
+    linux  /boot/${kernelfile} LABEL=cirros-rootfs ro console=tty0 console=hvc0
     initrd /boot/${initrdfile}
 }
 EOF