Table of contents
- Checkout out
- Build System
- Booting your kernel
- Debugging your kernel
A readonly git repository given by the LSE can be cloned:
git clone git://git.lse.epita.fr/k.git
Dependencies for building
Here is the description of some important files:
Makefile # top-level Makefile config.mk # build-system configuration k # kernel source folder k/crt0.S # crt0 for the kernel k/elf.h # ELF header k/include/k/iso9660.h # ISO filesystem definitions k/include/k/kfs.h # KFS structures definitions (deprecated) k/include/k/kstd.h # k standard definitions k/include/k/types.h # kernel types definitions k/k.c # kernel entry point k/k.lds # LD script for the kernel binary k/memory.* # kernel allocator k/multiboot.h # Multiboot Specification header libs # SDK folder libs/libc # a basic libc available everywhere libs/libk # userland functions roms # rom folder roms/chichepong # chichepong folder roms/roms.lds # LD script for rom binaries tools # Tools folder tools/create-iso.sh # small tool to generate the iso image tools/mkkfs # small program to create kfs roms tools/mkksf # small program to generate your own sounds
You will find the essential Intel Manuals describing the processor, all the instructions as well as the programming guide on the intel website.
The most interesting one is probably the “Volume 3A: System Programming Guide” which describe everything that is needed to develop an operating system.
The build system uses information stored in config.mk. Feel free to modify this file, but your project must work with the original one.
Here are make rules you need to know:
make | make k.iso # create an ISO with all the roms make k # compile your kernel make rom/GAME # compile the rom in the folder rom/$(GAME) make clean # clean the tree
Booting your kernel in qemu
qemu-system-x86_64 -cdrom k.iso [ -enable-kvm ]
Debugging your kernel
Build your kernel with debug flags.
- Run QEMU with a gdb server and stop the CPU at the first instruction:
qemu-system-x86_64 -cdrom k.iso -s -S
- Run gdb with your kernel binary:
- Once in gdb, connect to QEMU:
target remote localhost:1234
- Add some breakpoints:
- Run the simulation in gdb: