From 039afedbc80eea82266c324b6548d59dcd746098 Mon Sep 17 00:00:00 2001
From: Nathan Lee <me@nwlee.tech>
Date: Wed, 17 Jun 2026 13:03:33 -0500
Subject: fix memory issues and add basic device discovery

discuss: pci/dtb device discovery? now that the x0 issue is fixed it is
entirely possible.
---
 src/mem.rs | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

(limited to 'src/mem.rs')

diff --git a/src/mem.rs b/src/mem.rs
index 7458c67..2043aa1 100644
--- a/src/mem.rs
+++ b/src/mem.rs
@@ -38,10 +38,11 @@ impl Memory {
                 return Some(i);
             }
         }
+        eprintln!("tried to allocate {:X} but there are no more pages!", virtual_addr);
         None
     }
 
-    pub fn lookup_page(&mut self, virtual_addr: usize, permission: usize) -> Option<usize> {
+    fn lookup_page(&mut self, virtual_addr: usize, permission: usize) -> Option<usize> {
         for (i, page) in self.pages.iter().enumerate() {
             if page.virtual_addr == virtual_addr
                 && permission >= page.permission
@@ -50,7 +51,7 @@ impl Memory {
                 return Some(i);
             }
         }
-        return self.create_page(virtual_addr, permission);
+        self.create_page(virtual_addr, permission)
     }
 
     pub fn ro_lookup(&self, virtual_addr: usize, permission: usize) -> Option<usize> {
@@ -62,6 +63,7 @@ impl Memory {
                 return Some(i);
             }
         }
+        println!("virtual_addr {:X} is not allocated", virtual_addr);
         None
     }
 
@@ -69,21 +71,22 @@ impl Memory {
         let page = address & PAGE_MASK;
         let offset = address - page;
 
-        if let Some(page) = self.lookup_page(address, permission) {
+        if let Some(page) = self.lookup_page(page, permission) {
             self.memory[self.pages[page].real_addr + offset] = value;
-            Ok(())
-        } else {
-            Err(())
+            return Ok(());
         }
+        Err(())
     }
 
     pub fn read(&self, address: usize, permission: usize) -> Result<u8, ()> {
         let page = address & PAGE_MASK;
         let offset = address - page;
 
-        if let Some(page) = self.ro_lookup(address, permission) {
+        if let Some(page) = self.ro_lookup(page, permission) {
             Ok(self.memory[self.pages[page].real_addr + offset])
         } else {
+            println!("address {:X} is not allocated", address);
+
             Err(())
         }
     }
-- 
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