52 lines
2.0 KiB
Markdown
52 lines
2.0 KiB
Markdown
# AcadiaOS
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AcadiaOS is a hobby operating system I use to explore and learn about OS development.
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It is built on top of a small capability-based microkernel that provides
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memory management, process scheduling, and hardware access.
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## Directory Structure
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The subdirectories of the project are as follows:
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- **zion**: Contains kernel code as well as a couple headers that user space uses to interface with
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the kernel.
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- **lib**: Library code used by the kernel and user space.
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- **sys**: System services.
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- **sysroot**: Files that are copied to the root filesystem.
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- **toolchain** and **scripts**: Contain tooling for the cross-compile environment.
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- **yunq**: Contains the El Yunque IDL used for IPC between processes in userspace.
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Where available, further documentation about each of these components can be found in the README fi
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les in each respective subdirectory.
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## Building AcadiaOS
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Run `./scripts/build_toolchain.sh` to build a gcc cross-compile toolchain for the project. This
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step may take a long time (~5 mins on my new laptop, ~45 mins on my 2013 laptop).
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Run `./init-dbg.sh` to initialize the CMake project.
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Run `./scripts/qemu.sh` to build and run AcadiaOS in a VM. I usually run this from the `builddbg`
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directory so it is easier to run `ninja clean` when necessary (for instance when updating yunq
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files).
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### System Dependencies
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On arch linux I require the following packages to build this project:
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`base-devel limine dosfstools parted cmake ninja qemu-desktop qemu-system-x86`
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## Boot Process
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AcadiaOS uses the limine bootloader to enter into a 64-bit kernel in the negative 2GB address space
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(mcmodel kernel).
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The Zion kernel then sets up interrupts, scheduling, and memory management before passing off
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control to the Yellowstone process.
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The kernel passes capabilities to the Denali and VictoriaFalls binaries to the Yellowstone process
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to allow it to manage the rest of the boot process.
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The Yellowstone, Denali, and VictoriaFalls processes are all passed at boot using limine modules,
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however any subsequent processes are loaded off disk.
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