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https://github.com/dreamos82/Dreamos64
My experiments with osdev... again
https://github.com/dreamos82/Dreamos64
assembly c kernel operating-system operating-system-development operating-system-kernel operating-system-learning operating-systems-project osdev x86-64
Last synced: about 1 month ago
JSON representation
My experiments with osdev... again
- Host: GitHub
- URL: https://github.com/dreamos82/Dreamos64
- Owner: dreamos82
- Created: 2021-02-28T23:52:45.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2024-11-09T13:42:56.000Z (about 1 month ago)
- Last Synced: 2024-11-09T14:25:48.853Z (about 1 month ago)
- Topics: assembly, c, kernel, operating-system, operating-system-development, operating-system-kernel, operating-system-learning, operating-systems-project, osdev, x86-64
- Language: C
- Homepage:
- Size: 528 KB
- Stars: 164
- Watchers: 8
- Forks: 8
- Open Issues: 20
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
Awesome Lists containing this project
- awesome-os - Dreamos64 - An x86-64 hobby os built from scratch (Open Source Operating Systems)
README
# DreamOS64
[](https://github.com/dreamos82/Dreamos64/actions/workflows/c-cpp.yml) [](https://discordapp.com/channels/578193015433330698/578193713340219392) 
DreamOS64 is just my recent attempt to write a kernel again after many years far from osdev,
But this time in 64bit.
It is not a real replacement of the original DreamOS, and i don't really have any long term plans for it at the moment.
I started this project because i was missing the excitement of low-level programming :)
## What it does
Actually not much! :D
It just prints the OS name, a logo and few other string.
But at kernel level several things have been implemented:
* Long mode
* Kernel load in higher half
* Basic I/O functions (using the VGA bios)
* Basic framebuffer support (it can print strings on the screen, but only on the first half of the screen, the second half will cause a #PF for now)
* IDT Support
* It can load the kernel using 4kb pages or 2Mb pages
* Added support to access paging data structures with recursion tecnique.
* Implemented basic physical memory manager
* Enabled paging
* Implement basic kheap memory manager
* Added basic kmalloc, kfree
* Support Acpi V1 and V2
* Local Apic support
* IO-Apic support (Keyboard IRQ enable)
* Suppoort for PSF v1 and v2 fonts in framebuffer mode
* Basic keyboard driver and keyboard map (most of the keys are mapped)
* It prints the Epoch time! :)
* Extremely basic multi-task/multi-thread support
* Thread switching, thread_sleep and basic spinlock implementation
* Basic Virtual Memory implementation
* Initial Userspace support (so far can run only an idle userspace thread)
* Basic syscall mechanism (altough no real syscalls are implemented, just one that prints the string "example")
## Prerequisites:
These are the packages required to build and run it:
* nasm
* qemu and qemu-kvm
* grub-mkrescue
* grub-pc-bin
* xorriso
* mtools
* Gcc cross compiler or Clang
To build _Dreamos64_, a toolchain that supports the target architecture is required, it can be either `gcc` (in our case `x86-64`) or `clang` installed.
A complete guide on how to build the `gcc` cross-compiler, can be found [here](https://github.com/dreamos82/Osdev-Notes/blob/master/99_Appendices/E_Cross_Compilers.md), for `DreamOS64` the target architecture will be `x86-64`.
For `clang` we just need to install the `llvm`and the `lld` packages (the exact package name depends on the distribution used).
## Compiling and Running the OS
For a complete guide on how to build _DreamOS64_ and the parameters that are availables is in the docs folder: [docs/Building.md](docs/Building.md).
### Build the OS
Before building the os we need to copy a PSF font (either v1 or v2) in the fonts folder, and change its name to `default.psf` (even if we are building with framebuffer off).
Once all the parameters in `build/Config.mk` are set, to build just type:
```bash
make
```
It will use the default goal `build` and produce a bootable iso in the `dist/` folder called.
## Run and Debug
To launch the OS in qemu just use:
```bash
make run
```
Instead if we type:
```bash
make debug
```
It will compile the OS with the debug symbols enabled, all the output logging information will be sent to stdio.
Finally:
```bash
make gdb
```
Will compile the OS with debug symbol, and launch qemu with remote debugging enabled and will wait connection from gdb to start.
### Unit tests
There is a small set of tests implemented using asserts, if you want to run them just run:
```bash
make tests
```
### Known issues
* If at boot with qemu you get the following error message:
```
Booting from DVD/CD...
Boot failed: Could not read from CDROM (code 0009)
```
This means you are missing the grub-pc-bin package, and you need to install it.
* If the linking steps fail with several errors message like:
```
src/kernel/framebuffer/framebuffer.c:122: undefined reference to `_binary_fonts_default_psf_start'
```
This means that the fonts folder is missing (you need either a psf v2 or v1 font file in the fonts folder, the file has to be called default.psf)
### And now show time! :)
### Acknowledgements
Well so far a big thank you goes to [DeanoBurrito](https://github.com/DeanoBurrito) that implemented several stuff for Dreamos64 (x2apic, fixed some bugs, logging, and more to come...) not to mention his precious help explaining things and reviewing my crappy code :)
And his operating system is worth a mention too: [NorthPort](https://github.com/DeanoBurrito/northport)
Finally if you are interested in how to develop your own kernel, you can head to [https://github.com/dreamportdev/Osdev-Notes/](https://github.com/dreamportdev/Osdev-Notes/) a project mantained by me, and [DeanoBurrito](https://github.com/DeanoBurrito) on how to write a kernel from scratch.