How to debug RiscV UEFI with gdb

[wjh-study]

Now I want to debug UEFI with gdb.
when I use gdb-multiarch -tui SecMainRiscV64.debug and set breakpoint in: SecStartup,I set cmd continue.
But the Qemu can not stop in my breakpoint.How can I use gdb to set breakpoint to stop Qemu?
and, I want to know how to determine the entry point(the whole dsc)