e7a509176d
Added the cpptoml library (and license), and moved to using that for the initrd manifest. It's now possible to specify the `executable` flag for files, and the kernel correctly only launches new processes for the initrd files marked `executable`.
popcorn: A toy OS kernel
popcorn is the kernel for the hobby OS that I am currently building. It's far from finished, or even being usable. Instead, it's a sandbox for me to play with kernel-level code and explore architectures.
The design goals of the project are:
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Modernity - I'm not interested in designing for legacy systems, or running on all hardware out there. My target is only 64 bit architecutres, and modern commodity hardware. Currently that means x64 systems with Nehalem or newer CPUs and UEFI firmware. Eventually I'd like to work on an AArch64 port, partly to force myself to factor out the architecture-dependent pieces of the code base.
-
Modularity - I'd like to pull as much of the system out into separate processes as possible, in the microkernel fashion. A sub-goal of this is to explore where the bottlenecks of such a microkernel are now, and whether eschewing legacy hardware will let me design a system that's less bogged down by the traditional microkernel problems. Given that there are no processes yet, the kernel is monolithic by default.
-
Exploration - I'm really mostly doing this to have fun learning and exploring modern OS development. Modular design may be tossed out (hopefully temporarily) in some places to allow me to play around with the related hardware.
Building
Popcorn uses the waf build tool, which is included in the repo. The other
requirements are:
- python (to run waf)
- clang
- nasm
- mtools
After cloning, run waf configure. Then you can run waf build to build the
project, and waf test to run the tests. A floppy disk image will be built in
build/popcorn.img. If you have qemu-system-x86_64 installed, then you can
run waf qemu to run it in -nographic mode.
I personally run this either from a real debian amd64 testing/buster machine or a windows WSL debian testing/buster installation. The following should be enough to set up such a system to build the kernel:
sudo apt install qemu-system-x86 nasm clang-6.0 mtools
sudo update-alternatives /usr/bin/clang clang /usr/bin/clang-6.0 1000
sudo update-alternatives /usr/bin/clang++ clang++ /usr/bin/clang++-6.0 1000