faster memory impl

dsa-emu/src/memory/mod.rs

@@ -1,6 +1,9 @@
 use serde::{Deserialize, Serialize};
 
-use crate::memory::mmu::MMU;
+use crate::{
+    memory::{mainstore::RandomAccessMemory, mmu::MMU},
+    processor::processor::Emulator,
+};
 
 mod cache;
 pub mod mainstore;
@@ -15,7 +18,7 @@ pub enum FaultInfo {
 }
 
 #[repr(u32)]
-#[derive(Serialize, Deserialize, Clone, Copy)]
+#[derive(Serialize, Deserialize, Clone, Copy, Debug)]
 enum RegionType {
     Reserved,
     Bootloader,
@@ -25,14 +28,18 @@ enum RegionType {
     MMIO,
 }
 
-#[derive(Serialize, Deserialize, Clone, Copy)]
+#[derive(Serialize, Deserialize, Debug, Clone, Copy)]
 pub struct Region {
     base: PhysAddr,
-    size: usize,
+    size: u32,
     region_type: RegionType,
+
+    // flags for the emulator
+    #[serde(default)]
+    identity_map_on_boot: bool,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct MemoryMap {
     table_addr: PhysAddr,
     pub regions: Vec<Region>,
@@ -48,9 +55,27 @@ impl MemoryMap {
         }
     }
 
+    pub fn apply(&self, cpu: &mut Emulator<impl RandomAccessMemory>) {
+        for reg in &self.regions {
+            if reg.identity_map_on_boot {
+                Self::identity_map(cpu.mmu_mut(), reg);
+            }
+        }
+
+        let mem = cpu.memory_mut();
+        let mut offset = self.table_addr;
+        for region in &self.regions {
+            println!("Wrote entry: {region:?} to page table");
+            mem.write_word(offset, region.base);
+            mem.write_word(offset + 4, region.size);
+            mem.write_word(offset + 8, region.region_type as u32);
+            offset += 12;
+        }
+    }
+
     pub fn identity_map(mmu: &mut MMU, region: &Region) {
         let first_page = region.base >> 12;
-        let page_count = (region.size >> 12) as u32;
+        let page_count = (region.size >> 12);
 
         for page in (first_page..first_page + page_count).map(|p| p << 12) {
             mmu.create_mapping(page, page);
@@ -60,6 +85,6 @@ impl MemoryMap {
 
 impl Default for MemoryMap {
     fn default() -> Self {
-        ron::from_str(include_str!("../../config/dsa.mmap.ron")).unwrap()
+        ron::from_str(include_str!("../config/dsa.mmap.default.ron")).unwrap()
     }
 }