Debugging EXE File in Windbg and How to set Breakpoints in Assembly

Question

I am trying to set a breakpoint (created in assembly) and step into an EXE file line by line to watch registers and memory behavior. I have done this easily with gdb under Linux like this.

gdb -q ./AssembledLinkedFile -tui
break _start  (or break *&code for C using shellcode)
run
stepi

This works perfectly. However, The documentation for Windbg does not seem so straight forward.

Since using GoLink adds several lines of asm, I need to find my assembly and start at the beginning (_start:)

Current process.

1. Write my assembly program.
2. Assemble (on linux) - nasm -f win64 messageBox64bit.nasm -o messageBox64bit.obj
3. Link with golink (Windows) - golink \console messageBox64bit.obj
4. messageBox64bit.EXE created and works fine. Executed on Windows

After I open the messageBox64bit.EXE in Windbg, how can I set a breakpoint in my assembly (_start:), then step into?

Answer 1

It seems bp $exentry should set breakpoint on the entrypoint, then you can continue (g) until you hit it.