Hi Wilson,
On Fri, Aug 25, 2017 at 11:29 AM, Wilson Lee wilson.lee@ni.com wrote:
From: Keng Soon Cheah keng.soon.cheah@ni.com
Some device the serial console's initialization cannot run early during the boot process. Hence, nulldev serial device is helpful on that situation.
For example, if the serial module was implemented in FPGA. Serial initialization is prohibited to run until the FPGA was programmed.
I still don't fully understand this. Shouldn't the FPGA serial driver has some sort of register bits that determine if it's ready? And if not ready, the FPGA serial driver can do nothing like your null serial driver does?
This commit is to adding nulldev serial driver. This will allows the default console to be specified as a nulldev.
Signed-off-by: Joe Hershberger joe.hershberger@ni.com Signed-off-by: Keng Soon Cheah keng.soon.cheah@ni.com Cc: Chen Yee Chew chen.yee.chew@ni.com
drivers/serial/Kconfig | 7 ++++++ drivers/serial/Makefile | 1 + drivers/serial/serial_nulldev.c | 48 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 56 insertions(+) create mode 100644 drivers/serial/serial_nulldev.c
[snip]
Regards, Bin