console: add qemu debugcon detection
authorGerd Hoffmann <kraxel@redhat.com>
Thu, 30 May 2013 08:33:38 +0000 (10:33 +0200)
committerRonald G. Minnich <rminnich@gmail.com>
Wed, 5 Jun 2013 16:24:08 +0000 (18:24 +0200)
commit22f01e611be6fbd3ee5a70b27b96478ff1f4e93a
tree5c07114e40071065c33f0de56865c29bd5f3132a
parentd7c6e444acfc3284c4a9ff49dd138cd0c37545e2
console: add qemu debugcon detection

The qemu debugcon port returns 0xe9 on reads in case the device is
present.  Use that for detection and write console output to the
port only in case the device is actually present.

Change-Id: I41aabcf11845d24004e4f795dfd799822fd14646
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-on: http://review.coreboot.org/3338
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
src/console/qemu_debugcon_console.c