serial: Add Darwin/macOS support for custom and >230400 baudrates
This change is based on the patch proposed by Denis Ahrens in
https://review.coreboot.org/c/flashrom/+/67822
Change-Id: I3e6b88d2b4c2a130b16456752681fd9f807bf6f0
Signed-off-by: Peter Stuge <peter@stuge.se>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/70571
Original-Reviewed-by: Thomas Heijligen <src@posteo.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73480
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/serial.c b/serial.c
index cfc9b1e..d3a7e93 100644
--- a/serial.c
+++ b/serial.c
@@ -47,6 +47,10 @@
* On Linux there is a non-standard way to use arbitrary baud rates that we use if there is no
* matching standard rate, see custom_baud.c
*
+ * On Darwin there is also a non-standard ioctl() to set arbitrary baud rates
+ * and any above 230400, see custom_baud_darwin.c and
+ * https://opensource.apple.com/source/IOSerialFamily/IOSerialFamily-91/tests/IOSerialTestLib.c.auto.html
+ *
* On Windows there exist similar macros (starting with CBR_ instead of B) but they are only defined for
* backwards compatibility and the API supports arbitrary baud rates in the same manner as the macros, see
* http://msdn.microsoft.com/en-us/library/windows/desktop/aa363214(v=vs.85).aspx