Hi, I meet a boot failure when I use seabios to load my own boot loader on virtual machine. The error message printed on screen say that ”Error loading from operating system”, which neither comes from seabios or my boot loader(I have read the source code of seabios, but I didn’t find any code can print a such message). Actually I don’t know where the error message come from. Therefore I have to trace the execution of seabios and my boot loader. It seems like the error happens before seabios load my boot loader(in the file romlayout.S), but I don’t know the exact position. Can anyone tell me how to print something to screen in the romlayout.S? (I can’t use gdb to debug because the virtual machine is running on our own OS). Thank you very much. Yang Zhang