The start of interrupt and timer support, with some DeviceTree parsing.

1 files changed, 42 insertions, 3 deletions

diff --git a/kernel/src/lib.rs b/kernel/src/lib.rs
index 0a724c6..840f397 100644
--- a/kernel/src/lib.rs
+++ b/kernel/src/lib.rs
@@ -1,12 +1,21 @@
 #![no_std]
 
+#[macro_use]
+pub mod util;
+
+pub mod allocators;
+pub mod collections;
 pub mod console;
 pub mod device_tree;
-pub mod util;
+pub mod drivers;
+pub mod interrupts;
+pub mod prelude;
 
 #[cfg(not(test))]
 mod panic;
 
+use crate::prelude::*;
+
 /// The entrypoint to the kernel. This should be executed by hart0 alone. It performs some early
 /// boot tasks, then wakes up any other harts.
 ///
@@ -20,7 +29,7 @@ mod panic;
 pub unsafe extern "C" fn hart0_boot(device_tree: *const u8) -> ! {
     console::init();
 
-    log::info!("device_tree = {device_tree:?}");
+    info!("device_tree = {device_tree:?}");
     let flattened_device_tree = unsafe { device_tree::FlattenedDeviceTree::from_ptr(device_tree) }
         .expect("invalid DeviceTree");
     for event in flattened_device_tree.struct_events() {
@@ -28,5 +37,35 @@ pub unsafe extern "C" fn hart0_boot(device_tree: *const u8) -> ! {
         dbg!(event);
     }
 
-    todo!()
+    // Set up the allocator and the timer subsystem.
+    //
+    // TODO: The timer really oughta be later...
+    flattened_device_tree
+        .for_each_property(|node, prop, value| {
+            if node == ["", "cpus"] && prop == "timebase-frequency" {
+                if value.len() == 4 {
+                    let value = [value[0], value[1], value[2], value[3]];
+                    let timebase_frequency = u32::from_be_bytes(value);
+                    // SAFETY: Nobody is concurrently running, so they can't be concurrently
+                    // modifying this.
+                    unsafe {
+                        drivers::riscv_timer::TIMEBASE_FREQUENCY = timebase_frequency;
+                    }
+                    dbg!(timebase_frequency);
+                } else {
+                    warn!("/cpus/timebase-frequency was not a 4-byte quantity");
+                }
+            } else {
+                info!("{node}{prop} = {value:?}");
+            }
+            Ok(())
+        })
+        .map_err(|err| err.left_or_else(|void| void::unreachable(void)))
+        .expect("invalid DeviceTree");
+
+    interrupts::example_timer();
+    info!("sleeping forever...");
+    loop {
+        unsafe { core::arch::asm!("wfi") }
+    }
 }