The errors are addressed. There are signed and unsigned before portBASE_TYPE in serial.h. Once they are deleted, the errors are gone. Maybe is it because portBASE_TYPE is declared as uint16_t. I am not sure if it is good way to address these errors.
Glad you found the solution. Best to just delete the signed and unsigned qualifiers. I think this is a legacy issue from very early FreeRTOS versions that didn’t use stdint.h.
Thank you Richard for your help!
It might be relevant to portmacro.h for C28x, which is from thirty party. I took a look at a few other portmacro.h for other architectures, they are not defined as uint16_t. In this case, it should be ok to add signed or unsigned before portBASE_TYPE.