Removed messy debug logging, added print_oneshot!()

kernel/src/lib.rs

@@ -1,5 +1,6 @@
 #![no_std]
 #![feature(abi_x86_interrupt)]
+#![feature(impl_trait_in_bindings)]
 #![warn(
     clippy::correctness,
     clippy::nursery,
@@ -14,8 +15,6 @@
 extern crate alloc;
 
 use crate::{
-    // TODO: Fix nesting under `arch`. A lot of code does not NEED to run on
-    // x86_64. Note that the panic handler does.
     arch::x86_64::{
         cpu::apic::enable_apic,
         drivers::{
@@ -26,34 +25,29 @@ use crate::{
             allocation::{
                 heap_alloc::init_heap, page_alloc::FoundryOSFrameAllocator,
             },
-            init_page_table,
+            init_page_table, mapping,
             units::MemoryUnits,
         },
     },
     prelude::*,
 };
 
-use arch::x86_64::memory::mapping;
+use alloc::{boxed::Box, format};
 use core::arch::asm;
 use limine::BaseRevision;
 use std::unwind::UNWINDER;
 use x86_64::VirtAddr;
 
 pub mod arch;
+/// Commonly used re-exports.
+pub mod prelude;
 pub mod resources;
-#[allow(unused)] // We aren't using much of this right now.
+// We aren't using much of this right now.
+#[allow(unused)]
 pub mod std;
+mod step;
 pub mod util;
 
-pub mod prelude {
-    pub use crate::{
-        debug, debugln, eprint, eprintln, print, print_log, println,
-        println_log, serial_print, serial_println,
-        std::debug::_debug,
-        std::io::{_print, _print_err, _print_log, _serial_write},
-    };
-}
-
 /// Sets the base revision to the latest revision supported by the crate.
 /// See specification for further info.
 /// Be sure to mark all limine requests with #[used], otherwise they may be
@@ -73,12 +67,25 @@ pub fn hcf() -> ! {
     }
 }
 
+#[derive(Debug)]
+pub struct NoError {}
+
+impl core::fmt::Display for NoError {
+    fn fmt(&self, _f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        Ok(())
+    }
+}
+
+pub struct NoTags;
+
+impl core::error::Error for NoError {}
+
 /// Panicking before this is initialised is unwise. We should probably extract
 /// very early init into it's own function because Stack Traces may require
 /// allocations etc.
-pub fn boot() -> Result<(), &'static str> {
+pub fn boot() -> Result<(), Box<dyn core::error::Error>> {
     if !BASE_REVISION.is_supported() {
-        return Err("Base revision not supported");
+        return Err("Base revision not supported.".into());
     }
 
     use arch::x86_64::{gdt, interrupts};
@@ -116,22 +123,22 @@ pub fn boot() -> Result<(), &'static str> {
     FoundryOSFrameAllocator::init(memory_map);
     let available_bytes =
         FRAME_ALLOCATOR.get().unwrap().lock().available_memory();
+
     debugln!(
         "      => Available Memory: {}",
         MemoryUnits::from_bytes(available_bytes as usize)
     );
 
-    debugln!("[Success]");
-
+    // Allocations should be all fine past this point.
     debugln!("    Initialising Heap... ");
-    if unsafe { init_heap() }.is_err() {
-        return Err("Failed to initialise heap: error");
+    match unsafe { init_heap() } {
+        Ok(_) => debugln!("    [Success]"),
+        Err(why) => return Err(format!("{:?}", why).into()),
     }
-    debugln!("    [Success]");
 
-    // debug!("    Enabling PICs... ");
-    // interrupts::enable_pic();
-    // debugln!("[Success]");
+    debug!("    Enabling PICs... ");
+    interrupts::enable_pic();
+    debugln!("[Success]");
 
     debug!("    Disabling PICs... ");
     interrupts::disable_pic();
@@ -145,7 +152,9 @@ pub fn boot() -> Result<(), &'static str> {
     x86_64::instructions::interrupts::enable();
     debugln!("[Success]");
 
-    UNWINDER.lock(); // Initialises the Unwinder once and only once :fingers_crossed:.
+    // Initialises the Unwinder once and only once because this makes a heap
+    // allocation.
+    UNWINDER.lock();
 
     Ok(())
 }