console: add support for QEMU's debugcon
Add support for sending debug output to an I/O port.
It can be used together with QEMU's isa-debugcon driver to log the
coreboot output to a file. The port is configurable and defaults
to 0x402 which has established as the de facto standard. For example,
SeaBIOS+OVMF  use that one too.
Open Virtual Machine Firmware
Signed-off-by: Gerd Hoffmann <email@example.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <firstname.lastname@example.org>
Reviewed-by: Ronald G. Minnich <email@example.com>
3 files changed