`b' cannot be used because these format letters are also
used with the x command, where `b' stands for "byte";
see section Examining memory.
This is a way of removing
one word from the stack, on machines where stacks grow downward in
memory (most machines, nowadays). This assumes that the innermost
stack frame is selected; setting $sp is not allowed when other
stack frames are selected. To pop entire frames off the stack,
regardless of machine architecture, use return;
see section Returning from a function.
If you choose a port number that
conflicts with another service, gdbserver prints an error message
and exits.
In `gdb-4.15.1/gdb/refcard.ps' of the version 4.15.1 release.
If you have a more recent version of GDB than 4.15.1, look at the `README' file in the sources; we may have improved the installation procedures since publishing this manual.