docs/DEVELOPMENT.MD

@@ -2,44 +2,28 @@
 
 ## Design Goals & Philosophy
 
-General design goals are outlined in [DESIGN.md](DESIGN.md). Security-relevant
+General design goals are outlined in [DESIGN.md](DESIGN.md). Security-relevant design details can be found in [SECURITY.md](SECURITY.md).
-design details can be found in [SECURITY.md](SECURITY.md).
 
 ## Navigating
 
-- [kernel/](/src/kernel/): Kernel-specific code.
+* [kernel/](/src/kernel/): Kernel-specific code.
-  - [arch/](/src/kernel/arch/): Architecture specific features like the
+  * [arch/](/src/kernel/arch/): Architecture specific features like the display, serial, and interrupts. Each architecture is a subfolder, containing a file or module for each feature.
-  display, serial, and interrupts. Each architecture is a subfolder,
+  * [boot/](/src/kernel/boot/mod.rs): Handles bootloader-managed data structures. Gila uses Limine. Other bootloaders are NOT supported.
-  containing a file or module for each feature.
+    * [params.rs](/src/kernel/boot/params.rs): Command line parameter parsing.
-  - [boot/](/src/kernel/boot/mod.rs): Handles bootloader-managed data
+    * [modules.rs](/src/kernel/boot/modules.rs): Kernel module handling.
-  structures. Gila uses Limine. Other bootloaders are NOT supported.
+  * [constants.rs](/src/kernel/constants.rs): Constants referenced elsewhere in the kernel.
-    - [params.rs](/src/kernel/boot/params.rs): Command line parameter parsing.
+  * [device/](/src/kernel/device/mod.rs): Functions for discovering hardware and assigning drivers.
-    - [modules.rs](/src/kernel/boot/modules.rs): Kernel module handling.
+    -[acpi.rs](/src/kernel/device/acpi.rs): ACPI handling functions and structures.
-  - [constants.rs](/src/kernel/constants.rs): Constants referenced elsewhere
+  * [log.rs](/src/kernel/log.rs): Logging structures, macros, and singletons for logging to serial or the display.
-  in the kernel.
+  * [interrupt/](/src/kernel/interrupt/mod.rs): Interrupt handlers with platform-agnostic APIs.
-  - [device/](/src/kernel/device/mod.rs): Functions for discovering hardware
+  * [main.rs](/src/kernel/main.rs): The entry point that gets called by the bootloader.
-  and assigning drivers.
+  * [memory.rs](/src/kernel/memory.rs): Types relating to memory regions and allocation.
-    - [acpi.rs](/src/kernel/device/acpi.rs): ACPI handling functions and
+  * [panic.rs](/src/kernel/panic.rs): The panic handler and associated functionality.
-    structures.
+  * [process.rs](/src/kernel/process.rs): Process types and functions.
-  - [log.rs](/src/kernel/log.rs): Logging structures, macros, and singletons
+  * [syscall\_runner.rs](/src/kernel/syscall_runner.rs): Chooses a system call by its ID and defers actual syscall execution to code in `src/lib/`.
-  for logging to serial or the display.
+* [lib/](/src/lib/lib.rs): Library that all Gila's binary programs will be built against. Some of this code is shared with the kernel.
-  - [interrupt/](/src/kernel/interrupt/mod.rs): Interrupt handlers with
+  * [arch/](/src/lib/arch/mod.rs): Architecture specific functionality like system call register storing/loading.
-  platform-agnostic APIs.
+  * [syscall.rs](/src/lib/syscall.rs): System call types common to apps and the kernel.
-  - [main.rs](/src/kernel/main.rs): The entry point that gets called by the
-  bootloader.
-  - [memory.rs](/src/kernel/memory.rs): Types relating to memory regions and
-  allocation.
-  - [panic.rs](/src/kernel/panic.rs): The panic handler and associated
-  functionality.
-  - [process.rs](/src/kernel/process.rs): Process types and functions.
-  - [syscall\_runner.rs](/src/kernel/syscall_runner.rs): Chooses a system call
-  by its ID and defers actual syscall execution to code in `src/lib/`.
-- [lib/](/src/lib/lib.rs): Library that all Gila's binary programs will be
-built against. Some of this code is shared with the kernel.
-  - [arch/](/src/lib/arch/mod.rs): Architecture specific functionality like
-  system call register storing/loading.
-  - [syscall.rs](/src/lib/syscall.rs): System call types common to apps and
-  the kernel.
 
 ## Building and running
 
@@ -49,116 +33,74 @@ generated. However, it cannot be booted without installing it in a bootable
 Limine filesystem, and it cannot do anything useful without an initramfs
 containing system servers, such as the init server and device drivers.
 
-This project uses [cargo-make](https://github.com/sagiegurari/cargo-make) to
+This project uses [cargo-make](https://github.com/sagiegurari/cargo-make) to handle building ISOs and managing files not associated with Cargo. You need to install it before you can build an ISO automatically. To do so, you can run `cargo install cargo-make`. In addition, you will also need:
-handle building ISOs and managing files not associated with Cargo. You need to
-install it before you can build an ISO automatically. To do so, you can run
-`cargo install cargo-make`. In addition, you will also need:
 
-- `rustup` command installed
+* `rustup` command installed
-- `limine` command installed
+* `limine` command installed
-- `xorriso` command installed
+* `xorriso` command installed
-- `qemu-system-{your target architecture}` command installed (for running)
+* `qemu-system-{your target architecture}` command installed (for running)
 
 Then run `cargo make` to invoke the [Makefile.toml](Makefile.toml).
 
-- `cargo make clean_all`: Cleans all built binaries, libraries, initramfs
+* `cargo make clean_all`: Cleans all built binaries, libraries, initramfs files, and ISOs.
-files, and ISOs.
+* `cargo make lib`: Builds `libgila`, the library that the kernel and user code are linked against.
-- `cargo make lib`: Builds `libgila`, the library that the kernel and user
+* `cargo make kernel`: Builds the kernel ELF file.
-code are linked against.
+* `cargo make initramfs`: Build the init archive.
-- `cargo make kernel`: Builds the kernel ELF file.
+* `cargo make iso`: Builds the bootable ISO with Limine installed.
-- `cargo make initramfs`: Build the init archive.
+* `cargo make run`: Builds the ISO and boots it in QEMU.
-- `cargo make iso`: Builds the bootable ISO with Limine installed.
+* `cargo make debug`: Launch the kernel in QEMU with debugging enabled, and start and connect GDB.
-- `cargo make run`: Builds the ISO and boots it in QEMU.
-- `cargo make debug`: Launch the kernel in QEMU with debugging enabled, and
-start and connect GDB.
 
-You do not need to clean any files after making changes. The `lib`, `kernel`,
+You do not need to clean any files after making changes. The `lib`, `kernel`, and `iso` tasks will automatically be rerun if their input files change.
-and `iso` tasks will automatically be rerun if their input files change.
 
 ### Configuration
 
-- Variable `LIMINEDIR`: Location of binary files for limine. Default is
+* Variable `LIMINEDIR`: Location of binary files for limine. Default is `/usr/share/limine`.
-`/usr/share/limine`.
+* Variable `TARGET`: rustc target triple to compile for. Default is `x86_64-unknown-none`. Options are listed [in the targets section](#targets).
-- Variable `TARGET`: rustc target triple to compile for. Default is
+* Argument `-p`: Rust build profile to use. Default is `dev`. Options are `dev` and `release`.
-`x86_64-unknown-none`. Options are listed [in the targets section](#targets).
-- Argument `-p`: Rust build profile to use. Default is `dev`. Options are
-`dev` and `release`.
 
-> [!NOTE]
+> \[!NOTE]
-> The `-p {profile}` argument must go between `cargo make` and the task
+> The `-p {profile}` argument must go between `cargo make` and the task argument.
-argument.
 
 ### Features
 
-Gila has four optional features, which I made optional in anticipation of a
+Gila has four optional features, which I made optional in anticipation of a potential future port to older systems which might not support modern standards like UEFI or ACPI. They are all enabled by default. Disabling them reduces kernel size and forces the kernel to fall back to other implementations for some functionality like device discovery.
-potential future port to older systems which might not support modern
-standards like UEFI or ACPI. They are all enabled by default. Disabling them
-reduces kernel size and forces the kernel to fall back to other
-implementations for some functionality like device discovery.
 
-- `acpi`: Advanced Configuration and Power Interface, for device discovery &
+* `acpi`: Advanced Configuration and Power Interface, for device discovery & power management
-power management
+* `dtb`: Device Tree Blob, for device discovery in embedded systems
-- `dtb`: Device Tree Blob, for device discovery in embedded systems
+* `compression`: Compressed initramfs archive
-- `compression`: Compressed initramfs archive
+* `uefi`: Universal Extensible Firmware Interface specific bootloader features
-- `uefi`: Universal Extensible Firmware Interface specific bootloader features
 
 ### Targets
 
 Gila ~~currently supports~~ aims to support four different CPU architectures:
 
-- `x86_64`
+* `x86_64`
-- `aarch64`
+* `aarch64`
-- `riscv64`
+* `riscv64`
-- `loongarch64`
+* `loongarch64`
 
-It currently only builds on `x86_64`, and will continue to only support it
+It currently only builds on `x86_64`, and will continue to only support it until I can implement support for important features in other architectures.
-until I can implement support for important features in other architectures.
 
-All these architectures are supported by Limine, and the appropriate backends
+All these architectures are supported by Limine, and the appropriate backends are present in the Makefile to compile and build bootable images for each. While Limine and rustc also support `IA32` (also referred to as `i686`), support is missing from the [Limine crate](https://crates.io/crates/limine). Compilation will fail if a build for an unsupported target is attempted.
-are present in the Makefile to compile and build bootable images for each.
-While Limine (the bootloader) and rustc also support `IA32` (also referred to
-as `i686`), the Limine boot protocol cannot work on a 32-bit architecture, as
-it relies heavily on 64-bit pointers. Compilation will fail if a build for an
-unsupported target is attempted.
 
-EFI boot is presently supported, at least on `x86_64`. No features depend on
+EFI boot is presently supported, at least on `x86_64`. No features depend on EFI, and as such, the `uefi` feature can be safely disabled when booting through BIOS.
-EFI, and as such, the `uefi` feature can be safely disabled when booting
-through BIOS.
 
 ## Kernel Parameters
 
-Kernel parameters are passed as part of the `cmdline` through
+Kernel parameters are passed as part of the `cmdline` through [limine.conf](configs/limine.conf). The parameters are passed as a space-delimited list of keys and values. Keys begin with a hyphen (`-`), and keys are separated from their values with equals signs (`=`). Keys can have a set of multiple values, separated by a comma (`,`). Gila does not currently support parameter values with spaces. That would require an *actual* parser.
-[limine.conf](configs/limine.conf). The parameters are passed as a
-space-delimited list of keys and values. Keys begin with a hyphen (`-`), and
-keys are separated from their values with equals signs (`=`). Keys can have a
-set of multiple values, separated by a comma (`,`). Gila does not currently
-support parameter values with spaces. That would require an *actual* parser.
 
 List of current extant kernel parameters:
 
-- `-loglevel`: Can be a number or string corresponding to a log level. Only
+* `-loglevel`: Can be a number or string corresponding to a log level. Only one value supported. Current options are `Disabled`, `Trace`, `Info`, `Warning`, `Error`, and `Critical`. This parameter is case insensitive.
-one value supported. Current options are `Disabled`, `Trace`, `Info`,
+* `-logdev`: A sequence of one or more values representing devices to log to. Current options are `display` and `serial`. This parameter is case insensitive.
-`Warning`, `Error`, and `Critical`. This parameter is case insensitive.
+* `-initramfs`: A valid path to a module to serve as the initramfs (containing the init binary). Only one value supported. This parameter is case sensitive.
-- `-logdev`: A sequence of one or more values representing devices to log to.
-Current options are `display` and `serial`. This parameter is case
-insensitive.
-- `-initramfs`: A valid path to a module to serve as the initramfs (containing
-the init binary). Only one value supported. This parameter is case sensitive.
 
 The default behavior for each parameter, when not supplied, is:
 
 `-loglevel=Info -initramfs=/boot/initramfs.tar.lzma`
 
-The `.lzma` extension is removed from the default initramfs name when
+The `.lzma` extension is removed from the default initramfs name when compression is disabled. It must also be changed in [limine.conf](configs/limine.conf) or else Limine will not load it.
-compression is disabled. It must also be changed in
-[limine.conf](configs/limine.conf) or else Limine will not load it.
 
 ## Writing Programs for Gila
 
-Gila's system calls will soon be fully defined in `libgila`. The library is
+Gila's system calls will soon be fully defined in `libgila`. The library is developed in tandem with, and is used within, the kernel. As Gila does not currently support any kind of Rust or C standard library, you must compile your programs for the same architecture as Gila itself, bare metal. Userspace programs must not use any privileged instructions that would cause an exception if running in Ring 3 or any other least-privileged mode of a processor.
-developed in tandem with, and is used within, the kernel. As Gila does not
-currently support any kind of Rust or C standard library, you must compile
-your programs for the same architecture as Gila itself, bare metal. Userspace
-programs must not use any privileged instructions that would cause an
-exception if running in Ring 3 or any other least-privileged mode of a
-processor.