+A significant amount of effort has gone into crafting clean abstractions,
+implementing advanced kernel features, and applying performance optimizations
+throughout the system.
+
+To better illustrate the scope of work already done, the following non-exhaustive
+list outlines currently supported features in Lunaix:
+
+### List of All Features
+<details>
+
+<summary>Click to Expand</summary>
+
++ Multi-ISA
+ + x86_32
+ + x86_64
+ + Aarch64 (WIP)
++ Boot protocol
+ + abstraction for different protocol
+ + configurable kernel boot-time parameters
++ Platform resource management and definition
+ + read-only ACPI table interpretation
+ + full devicetree implementation
++ Memory management
+ + architecture-neutral abstraction
+ + highmem
+ + copy-on-write
+ + page sharing
+ + explicit huge page
+ + on-demand paging
+ + compound page
+ + reverse mapping (rmap)
+ + memory compaction (WIP)
+ + slab-style object allocator
+ + inter-process address space access
++ Multi-tasking
+ + fully preemptive
+ + protection levels
+ + process isolation
+ + native threading
+ + signal mechanism
+ + round-robin scheduler (for now)
+ + kernel level multi-tasking (i.e. kernel threads)
+ + taskfs: file system interface to process and threads
++ File system
+ + POSIX-compliant interface
+ + virtual file system framework
+ + file system mounting mechanism
+ + page cache for file IO
+ + inode/dnode caching
+ + ext2 (rev.0, rev.1)
+ + iso9660 (rock-ridge)
+ + twifs: kernel state fs interface.
++ Device management and interrupt handling
+ + unified IRQ framework
+ + unified driver framework for heterogenous devices
+ + modular driver model allow compiled-time toggling
+ + asynchronous operation model supported
+ + devfs: device fs interface.
++ Block I/O (blkio)
+ + unified block IO interface
+ + IO request packets caching
+ + asynchronous IO operation
++ Serial I/O
+ + POSIX-compliant serial IO model
++ Caching Infrastructure
+ + LRU replacement policy and pooling
+ + kernel daemon for dynamic and transparent cache managements
++ Error handling and detection
+ + stack backtracing with symbol resolution
+ + stack unwinding for nested exception
+ + CPU state dumping
+ + deadlock/hung-up detection
+
+</details>
+
+### List of Built-in Drivers
+
+<details>
+
+<summary>Click to Expand</summary>
+
++ Architecture Neutral
+ + UART 16650-compatible driver
+ + Serial ATA AHCI
+ + PCI 3.0
+ + PCIe 1.1
+ + Standard VGA
++ Intel x86
+ + RTC (Intel PCH)
+ + IOAPIC IRQ controller
+ + APIC Timer
+ + Legacy i8042 keyboard controller
++ ARM
+ + GICv3
+ + PL011 (WIP)
+</details>
+
+## Documentations
+
+There are documentations avaliable if you want to dig deeper. Keep in mind they are still work in progress and missing localisation.
+
++ [Luna's Tour - Into Lunaix's Inner Workings](docs/lunaix-internal.md)
++ [Syscall Number Assignments](docs/lunaix-syscall-table.md)
+
+## Compile and Build
+
+Building lunaix is simple, no more bloated dependencies to install, basic
+`build-essentials` installation plus a python are sufficient.
+
++ gcc (recommend v12+)
++ binutils
++ make
++ python (recommend v3.11+)
+
+And also one should have environment variable `ARCH=<arch>` exported, where
+`<arch>` is one of the supported arhcitecture (`x86_32`, `x86_64`, `aarch64`).
+
+For cross compilation, also export `CX_PREFIX` to the gcc prefix for the
+corresponding `<arch>`.
+
+The following `make` actions are then available to use.
+
+| Make command | Usage |
+| ---- | ---- |
+| `make all` | Build the kernel bin |
+| `make rootfs` | Build the stock rootfs |
+| `make clean` | clean |
+| `make config` | run configuration tool |
+| `make reconfig` | revert to default and restart configuration |
+
+A successful build will give `build/bin/kernel.bin`.
+
+> Please note: this is the kernel, not a bootable image, it require a bootloader
+> to boot and specify the rootfs.
+
+## Get Started
+
+If you are impatient, or just want something to run and don't want to went
+through tedious process of configuring rootfs and tweak kernel parameters. You
+can use the `live_debug.sh` provided in the lunaix root directory to quickly
+bring up the system with default parameters (also used by the author for
+debugging).
+
+### Quick Start
+
+This will get you up and running real quick. We will use `x86_64` as example.
+
+Assuming a Linux or other Unix-like shell environment. We also expect you to be able to sort out trivial issues like missing packages.
+
+**Select your target**
+```sh
+$ export ARCH=x86_64
+```
+
+**Check Python**
+```sh
+$ python --version
+```
+
+Ensure at least `3.11`
+
+**Check compiler**
+```sh
+$ gcc -dumpmachine
+```
+
+Ensure `x86_64-linux-gnu` or anything resemble `x86_64`
+
+**Check QEMU**
+```sh
+$ which qemu-system-x86_64
+```
+
+Should display a valid installation path
+
+**Optional: Setting up Cross-Compiler**
+
+```sh
+$ export CX_PREFIX=x86_64-linux-gnu-
+```
+
+**Run Configuration**
+```sh
+make config
+```
+
+Then hitting `q` in the interactive shell to accept default setting.
+
+**Build stock rootfs**
+
+```sh
+make rootfs
+```
+
+Note, this requires root for creating fs image. You can check script `lunaix-os/scripts/mkrootfs` if you feel uncertain.
+
+**Build & Run**
+```sh
+./live_debug.sh
+```
+
+you should see gdb now take control of your shell
+
+**Connect to serial via telnet**
+
+Open up another window or session
+```sh
+telnet localhost 12345
+```
+
+**Commence simulation**
+
+Back to the gdb session and type `c` to countine
+
+
+**Watch Lunaix booting!**
+
+Congrats, enjoy your lunaix! (or submit an issue)
+
+
+### Not so Quick Start
+
+Here is a slower and yet more verbose steps:
+
+1. Select an architecture `<arch>`
+2. Check the compilation prerequisites and presence of `qemu-system-<arch>`
+3. Optionally export `CX_PREFIX` if you are building for another architecture.
+4. Run `make ARCH=<arch> rootfs` to build stock rootfs image, require support
+ of `dd`，`mkfs.ext2`, `mount -o loop`, `mktemp`.
+5. Run `ARCH=<arch> live_debug.sh` to boot in QEMU with gdb hooked (one should
+ see a gdb session)
+6. telnet to `localhost:12345`, this is QEMU emulated serial port
+7. type `c` in the active gdb session and commence emulation.
+8. Congrats, enjoy your lunaix!
+(or submit an issue)
+
+
+## Booting the kernel
+
+Since lunaix is a kernel, much like linux. It requires additional setup to do
+the magic. And, as in "much like linux", methods to make linux kernel boot can
+also apply to lunaix without or with little translation, as we will discuss
+below.
+
+The bootloader part is generic, any bootloader, for example GRUB will work (not
+tested for UEFI, but I expect this would be an exception), or booting up in QEMU
+using `-kernel` option
+
+The kernel command line, is however, a bit differentiated.
+The syntax is similar, both takes form of space-separated array of `<key>=<val>`
+pairs or boolean `<flag>`.
+
+Currently, lunaix support the following options
+
+| Option | Default Value | Optional | Usage |
+| ------ | ---- | ----- | ---- |
+| console | `/dev/ttyS0` | No | Specify the system console device, path within lunaix's devfs |
+| rootfs | `/dev/block/sda` | No | Specify the device contain rootfs image, path within lunaix's devfs |
+| init | `/init` | Yes | Path within rootfs of the `init` |
+
+
+## Submit an Issue
+
+If one ran into bug, one can submit an issue by filling up the following template
+
+```
+1. Describe the problem
+ "How does it look like, anything descriptive: visual, sonic, emotional experience"
+
+2. Steps to reproduce
+ "How you ran into this mess?"
+
+3. Expected behaviour
+ "What do you intended/expected to achieve/to be"
+
+4. Lunaix's panic trace (if applicable)
+
+5. Other clues that you think might be helpful
+```
+
+
+## Limitations
+
+The development process is still in motion, any limitation can be categorised as
+a feature yet to be. However, some features that the author considered to be the
+most urgent and wish the matters to be discussed.
+
+Lunaix is under impression of uniprocessor and not capable of running in SMP
+environment. This is major held back of being a modern operating system. It has
+the highest priority among all other tasks
+
+Lunaix do not have a mature (or even, an infant) user space ecosystem, mainly
+because the lack of a proper and sophisticated libc. Efforts need to be done for
+porting one to the target. However, given the author's tight schedule, this task
+is unfortunately still beyond the horizon.
+
+## Acknowledgement
+
+Albeit one must realise that the author has mentioned it in the very beginning,
+the author would like to emphaise **again** on the nature of this project.
+
+As a personal challenge, this project is independently developed by the author
+single-handly, which means:
+
++ No reference to existing tutorials, books, online courses or any open source
+ project that might provide any example, hint or working prototype on the
+ design and implementation of kernel, subsystems or anythings that can be
+ contributed towards a working prototype.
++ The author has no prior knowledge on Linux kernel through out 90% of the
+ project time.
++ All knowledge on the kernel design is coming from the basic textbook on
+ operating system theory, that is, *Modern Operating System* by Tanenbaum.
++ All knowledge on the system programming is coming from the basic textbook,
+ that is, *Computer System - A Programmer's Perspective Third Edition*
++ All knowledge on the generic framework design and driver development are
+ ingested from various technical specifications gathered across the Internet.
+
+## References
+
++ Intel 64 and IA-32 Architecture Software Developer's Manual (Full Volume Bundle)
++ ACPI Specification (version 6.4)
++ Devicetree Specification
++ ARM® Generic Interrupt Controller (v3)
++ Arm® Architecture Reference Manual (Profile-A)
++ Procedure Call Standard for the Arm® 64-bit Architecture (AArch64)
git://scm.lunaixsky.com / lunaix-os.git / blobdiff