From 548905a86473101325540446f35ffda8acd0c3bb Mon Sep 17 00:00:00 2001
From: Nathan Lee <me@nwlee.tech>
Date: Fri, 25 Sep 2026 23:24:31 -0500
Subject: scaffold kernel from parts of wkern x86

---
 website-emu/src/lib.rs | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

(limited to 'website-emu/src')

diff --git a/website-emu/src/lib.rs b/website-emu/src/lib.rs
index 7c1a285..ffaa677 100644
--- a/website-emu/src/lib.rs
+++ b/website-emu/src/lib.rs
@@ -11,8 +11,41 @@ const REGISTER_NAME_WIDTH: u32 = 0b11111;
 
 const DRAM_LOAD: u32 = 0x20000000;
 const OS_LOAD: u32 = 0x80000000;
+
+const CONSOLE_LOAD: u32 = 0x70000000;
+
 const INITRD_LOAD: u32 = 0;
 
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(js_namespace = console)]
+    fn log(s: &str);
+}
+
+pub struct Uart {
+    pub addr: u32,
+    pub value: u8
+}
+
+impl MemoryDevice for Uart {
+    fn read(&self, address: u32) -> Result<u8, ()> {
+        if (address == self.addr) {
+            Ok(self.value)
+        } else {
+            Err(())
+        }
+    }
+
+    fn write(&mut self, address: u32, value: u8) -> Result<(), ()> {
+        if (address == self.addr) {
+            self.value = value;
+            Ok(())
+        } else {
+            Err(())
+        }
+    }
+}
+
 #[wasm_bindgen]
 pub fn boot(image: &[u8], initrd: &[u8], memory: &[u8]) {
     let mut cpu_memory = CpuMemory {
@@ -41,10 +74,27 @@ pub fn boot(image: &[u8], initrd: &[u8], memory: &[u8]) {
         dram: initrd.to_vec().into_boxed_slice(),
     };
 
+    let uart = Uart {
+        addr: CONSOLE_LOAD,
+        value: 0
+    };
+
     cpu_memory.register_device(
         DRAM_LOAD..DRAM_LOAD + memory_len as u32,
         Box::new(ram_device)
     );
+    cpu_memory.register_device(
+        OS_LOAD..OS_LOAD + os_size as u32,
+        Box::new(os_image)
+    );
+    cpu_memory.register_device(
+        INITRD_LOAD..INITRD_LOAD + initrd_size as u32,
+        Box::new(initrd_image)
+    );
+    cpu_memory.register_device(
+        CONSOLE_LOAD..CONSOLE_LOAD + 1,
+        Box::new(uart)
+    );
 
     let mut state = CpuState::new(cpu_memory);
 
-- 
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