riscv target spec for newlib and rtems

[Matt Wette]

Hi All,

I'm working on compiling binutils, gcc, newlib and rtems-5.3 for 
RISC-V.   What is appropriate target-spec?
I've searched for specification hints but can't anything. Currently, I'm 
using riscv-rtems-elf but it seems
newlib and rtems want to see a target spec with four fields and rtems is 
#3 or #4 in the list.
Any references for this?

for reference, using binutils-2.38, gcc-12.3.0 and newlib-4.3.0.20230120
I've gotten binutils, gcc and newlib to build (with patch to deal with 
above config issue on newlib).

Matt