NULLs in SWO output

[RobMeades]

Description

With the introduction of #5571, it is now possible to redirect stdio to SWO really easily, which is very sweet indeed. There is an issue, though, which is that one character of output is written as an ITM 32-bit word. The two clients I have used (GDB and JLinkSWOViewer) interpret each byte of the 32-bit word as an individual character and so either emit three white-space characters (GDB) or, seeing NULL, terminate the string and print nothing more (JLinkSWOViewer), which is not really usable.

@kjbracey-arm is fixing this in #7371.

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

[ciarmcom]

ARM Internal Ref: MBOTRIAGE-982