Does the MSP430 port support the MSP430X extended architecture, including 20-bit address? What about compiling with Code Composer 3.2? As far as I know the MSP430 version of GCC does not support the 430X extensions to any useful degree.

Google for "Westmoorland Engineering FreeRTOS". You will find an X port there.

The Westmoreland Engineering website appears to be inactive, no recent updates. I sent an email, no response.

In looking at a port for MSP430X, the big differences are 20 bit address and registers. The task stack size will have to be doubled over an MSP430 to push the larger register set, but context switches should be about the same since the 430X has a push/pop multiple instruction. The other difference is in handling interrupt return address (hi 4 bits of PC stored with status register). Has anyone else looked at what it would take to do a port from MSP430 to MSP430X?

And does anyone know if there are plans to fully support the 430X in GCC? Doesn't seem to be much effort in that direction from what I can find on a web search.

I'm also looking for a MSP430X port at the moment, and I've also tried to contact Westmoreland Engineering at the website, without response... So, does anyone else have this particular port?
It should be possible to make a port for MSP430X, but it would ofcourse be nice to get inspired from someone who has already made it! (Or thought about it at least ...)

I found this old thread, which covers some of the aspects of the X-port:

https://sourceforge.net/forum/message.php?msg_id=4456703

BTW, I'm using CCE and want to try out FreeRTOS on a MSP430F5418.

Regards.