Bochs is a PC emulator. I've introduced it in my blog page.
Bochs reads a file, BIOS-bochs-latest file, to be a BIOS of the PC emulator. We know that CPU considers the address f000:fff0 as a BIOS entry point when the PC is power on. So we open the BIOS file to get the last line.
We can find that there are machine codes and a date signature, 08/02/13, that I guess as the released date of the BIOS. What do the machine codes mean? Le's use debug command in prompt.
> copy BIOS-bochs-latest test.bin
> debug test.bin
So the the assembly language of the machine codes is JMP F000:E05B. Le's show the machine codes at F000:E05B.
The code started at XOR is POST Entry Point. Please refer the link to know what it is.
Above is a way to manually trace the BIOS entry point. How to use Bochs to easily trace it? Just run bochsdbg.exe, a debug mode of Bochs.
It is just like the DOS debug command, it is broken at the line of <bochs:1> to wait for user command. I send the help command to display how to use it. Then I select the n command to trace BIOS entry point step by step. It displays in assembly language and teaches us how BIOS entry point works. Is it interesting?