Semihosting output on ARM7TDMI

[Andrew Cagney]

> It looks like it needs to be changed so that it is
> pre-initialized so that stdin, stdout, and stderr are
> "pre-opened".  I think you'll need to change the code in
> rdi-share/hsys.c HostSysInit() so that fds 0,1,2, are
> initialized to map to FILE pointers stdin, stdout, stderr.


Almost.  The theory is right.

For output the ``struct ui_file'' objects gdb_std*, normally target 
output is sent to gdb_stdtarg (one day I'll remember to rename it to 
gdb_targout).

For input, things get messy, if you look at remote.c and fixme's from me 
there are hopefully enough hints on how it can be done, in theory.  It 
is made complicated by the fact that there is an event look wanting a 
look-in.

	Andrew