progress: new assembler works, instruction set fully implemented with call/ret and push/pop, bf.dsa works which means the dsa assembly language works reliably. still a few bugs to fix. might be able to squeeze out a tiny bit more performance

dsa/emulator/src/memory/ram/prealloc.rs

@@ -0,0 +1,50 @@
+use crate::memory::{
+    PhysAddr, RandomAccessMemory,
+    ram::{NUM_PAGES, Page},
+};
+
+pub struct PreAllocStore {
+    heap: Box<[u8; NUM_PAGES * 4096]>,
+}
+
+unsafe impl Send for PreAllocStore {}
+impl PreAllocStore {
+    pub fn new() -> Self {
+        Self {
+            heap: unsafe { Box::new_zeroed().assume_init() },
+        }
+    }
+}
+
+impl RandomAccessMemory for PreAllocStore {
+    #[inline(always)]
+    fn read_word(&self, addr: PhysAddr) -> u32 {
+        unsafe { (self.heap.as_ptr().add(addr as usize) as *const u32).read() }
+    }
+
+    #[inline(always)]
+    fn read_byte(&self, addr: PhysAddr) -> u8 {
+        self.heap[addr as usize]
+    }
+
+    #[inline(always)]
+    fn read_page(&self, addr: PhysAddr) -> &Page {
+        debug_assert_eq!(addr % 4096, 0);
+        unsafe { (self.heap.as_ptr().add(addr as usize) as *const Page).as_ref_unchecked() }
+    }
+
+    #[inline(always)]
+    fn write_byte(&mut self, addr: PhysAddr, value: u8) {
+        self.heap[addr as usize] = value;
+    }
+
+    #[inline(always)]
+    fn write_word(&mut self, addr: PhysAddr, value: u32) {
+        unsafe { (self.heap.as_ptr().add(addr as usize) as *mut u32).write(value) };
+    }
+
+    #[inline(always)]
+    fn write_page(&mut self, addr: PhysAddr, value: &Page) {
+        self.heap[addr as usize..addr as usize + 4096].copy_from_slice(value);
+    }
+}