USART driver implementations for platforms included in TF-M
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Description

As already mentioned all USART drivers implemented for various platforms included in TF-M are not compliant with CMSIS USART Driver specification. They implement blocking send/receive and no power on/off.

Drivers should be rewritten and should pass the CMSIS Driver Validation.

RobertRostohar triaged this task as High priority.
davidwang claimed this task.
davidwang added a subscriber: mingyangSun.
mingyangSun added a comment.EditedTue, Dec 3, 2:07 AM

Hi, @RobertRostohar
If we remove the "FILE stdout" declaration from uart_stdout.c as mentioned(It prevents Clib mutex initialization), ARMCLANG image will not output anything anymore.
As the example shown in the link:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0475m/chr1359122861400.html
"FILE
stdout" is needed for retargeting.
We do not have the same environment(CMSIS-Pack with MDK environment) to reproduce the output in your environment.
Wonder if you knew the root cause of why "FILE __stdout" prevents Clib mutex initialization?

It seems that we can reimplement low level I/O functions such as _sys_write() and _ttywrch(). In that way, we do not need to declare "FILE __stdio".