Wrote stack unwinder. NEEDTO: fix NoUnwindInfo

Probably incorrect PC was set.

kernel/src/lib.rs

@@ -12,23 +12,33 @@
 )]
 
 extern crate alloc;
-use crate::{arch::x86_64::memory::init_page_table, prelude::*};
-use arch::x86_64::memory::allocation::heap_alloc::init_heap;
+
+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::{
+            ascii::screensize_chars, framebuffer::display::screensize_px,
+        },
+        memory::{
+            FRAME_ALLOCATOR,
+            allocation::{
+                heap_alloc::init_heap, page_alloc::FoundryOSFrameAllocator,
+            },
+            init_page_table,
+            units::MemoryUnits,
+        },
+    },
+    prelude::*,
+};
+
 use arch::x86_64::memory::mapping;
 use core::arch::asm;
 use limine::BaseRevision;
-use std::unwind;
-use std::unwind::eh_info::ELF;
 use x86_64::VirtAddr;
-use arch::x86_64::memory::allocation::page_alloc::FoundryOSFrameAllocator;
-use crate::arch::x86_64::cpu::apic::enable_apic;
-use crate::arch::x86_64::drivers::ascii::screensize_chars;
-use crate::arch::x86_64::drivers::framebuffer::display::screensize_px;
-use crate::arch::x86_64::memory::FRAME_ALLOCATOR;
-use crate::arch::x86_64::memory::units::MemoryUnits;
 
 pub mod arch;
-mod panic;
 pub mod resources;
 #[allow(unused)] // We aren't using much of this right now.
 pub mod std;
@@ -36,11 +46,10 @@ pub mod util;
 
 pub mod prelude {
     pub use crate::{
-        eprint, eprintln, print, print_log, println, println_log, serial_print,
-        serial_println,
-        debug, debugln,
-        std::io::{_print, _print_log, _serial_write, _print_err},
+        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},
     };
 }
 
@@ -54,13 +63,6 @@ pub mod prelude {
 #[unsafe(link_section = ".requests")]
 static BASE_REVISION: BaseRevision = BaseRevision::new();
 
-#[panic_handler]
-fn rust_panic(_info: &core::panic::PanicInfo) -> ! {
-    println!("Kernel panic: {}", _info);
-    serial_println!("Kernel panic: {}", _info);
-    hcf();
-}
-
 pub fn hcf() -> ! {
     loop {
         unsafe {
@@ -70,6 +72,9 @@ pub fn hcf() -> ! {
     }
 }
 
+/// 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> {
     if !BASE_REVISION.is_supported() {
         return Err("Base revision not supported");
@@ -104,11 +109,16 @@ pub fn boot() -> Result<(), &'static str> {
     debugln!("[Success]");
 
     debugln!("    Initialising Memory Subsystem... ");
-    let physical_memory_offset = VirtAddr::new(*mapping::PHYSICAL_MEMORY_OFFSET);
+    let physical_memory_offset =
+        VirtAddr::new(*mapping::PHYSICAL_MEMORY_OFFSET);
     init_page_table(physical_memory_offset);
     FoundryOSFrameAllocator::init(memory_map);
-    let available_bytes = FRAME_ALLOCATOR.get().unwrap().lock().available_memory();
-    debugln!("      => Available Memory: {}", MemoryUnits::from_bytes(available_bytes as usize));
+    let available_bytes =
+        FRAME_ALLOCATOR.get().unwrap().lock().available_memory();
+    debugln!(
+        "      => Available Memory: {}",
+        MemoryUnits::from_bytes(available_bytes as usize)
+    );
 
     debugln!("[Success]");
 
@@ -134,16 +144,5 @@ pub fn boot() -> Result<(), &'static str> {
     x86_64::instructions::interrupts::enable();
     debugln!("[Success]");
 
-    debug!("    Setting up stack unwinder, panic handler... ");
-    // Setup stack traces and proper panic handler. TODO: Handle panics
-    // differently if not initialised.
-    let eh_frame_ptr = ELF
-        .get_section_addr(".eh_frame_hdr")
-        .expect("Could not get `.eh_frame_hdr` address.");
-
-    let _eh_info =
-        unsafe { unwind::eh_info::EhInfo::from_hdr_ptr(eh_frame_ptr) };
-    debugln!("[Success]");
-
     Ok(())
 }