EvOS

Multitasking OS and kernel with an interactive shell.

Debugging with GDB

1. Run gdb:

   $ gdb

2. Load symbol file:

   add-symbol-file <root>/build/kernelfull.o 0x100000

3. Set a breakpoint:

   break kernel_main

4. Attach the debugger to QEMU:

   target remote | qemu-system-x86_64 -S -gdb stdio -hda ./os.bin

Cheat sheet

Command	Description
c	Continue
layout asm	Enter assembly layout
layout src	Enter source layout
step	Step program until it reaches a different source line
stepi	Step one instruction exactly
finish	Complete the current stack frame

References

• BIOS routines
• Cross compiler