Signal numbers?

I was wondering...
How can I find out which signal numbers GDB uses for which signals?

I got my bare metal "kind of gdb server/stub" working, but I wish I
could give some reasonable signal numbers in the stop-messages.

It's not nice if stop due to a breakpoint is reported to user as
"SIGPIPE" by the gdb. ;-)

I thought I sent SIGUSR2 (signal 12) when the debuggee stopped at
breakpoint in the program code (not one of debugger's) and GDB
notified: "Program received signal SIGTSTP, Stopped (user)."
Also signal 7 seems to come out as SIGEMT instead of SIGBUS
(prefetch/data aborts).