stores

Cargo.lock

@@ -29,12 +29,6 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 name = "compiler"
 version = "0.1.0"
 
-[[package]]
-name = "convert_case"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
-
 [[package]]
 name = "delegate"
 version = "0.9.0"
@@ -46,19 +40,6 @@ dependencies = [
  "syn 1.0.109",
 ]
 
-[[package]]
-name = "derive_more"
-version = "0.99.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fb810d30a7c1953f91334de7244731fc3f3c10d7fe163338a35b9f640960321"
-dependencies = [
- "convert_case",
- "proc-macro2",
- "quote",
- "rustc_version",
- "syn 1.0.109",
-]
-
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -93,7 +74,6 @@ name = "hbvm"
 version = "0.1.0"
 dependencies = [
  "delegate",
- "derive_more",
  "hashbrown",
  "hbbytecode",
  "log",
@@ -186,21 +166,6 @@ version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
-[[package]]
-name = "rustc_version"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
-dependencies = [
- "semver",
-]
-
-[[package]]
-name = "semver"
-version = "1.0.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"
-
 [[package]]
 name = "static_assertions"
 version = "1.1.0"

hbvm/Cargo.toml

@@ -8,7 +8,6 @@ lto = true
 
 [dependencies]
 delegate          = "0.9"
-derive_more       = "0.99"
 hashbrown         = "0.13"
 hbbytecode.path   = "../hbbytecode"
 log               = "0.4"

hbvm/src/vm/mem/mod.rs

@@ -57,6 +57,49 @@ impl Memory {
 
     /// Load value from an address
     pub fn load<S: MemAccessSize>(&self, addr: u64) -> Option<Value> {
+        let lookup = self.page_lookup(addr)?;
+        match lookup.perm {
+            Permission::Empty | Permission::Node => None,
+            Permission::Readonly | Permission::Write | Permission::Exec => {
+                let mut value = MaybeUninit::<Value>::zeroed();
+                unsafe {
+                    core::ptr::copy_nonoverlapping::<u8>(lookup.ptr, value.as_mut_ptr().cast(), 1);
+                    Some(value.assume_init())
+                }
+            }
+        }
+    }
+
+    /// Store value to an address
+    pub fn store<S: MemAccessSize>(&mut self, addr: u64, value: Value) -> Result<(), ()> {
+        let lookup = self.page_lookup(addr).ok_or(())?;
+        match lookup.perm {
+            Permission::Write => {
+                unsafe {
+                    core::ptr::copy_nonoverlapping::<u8>(
+                        (&value as *const Value).cast(),
+                        lookup.ptr,
+                        1,
+                    )
+                };
+                Ok(())
+            }
+            _ => Err(()),
+        }
+    }
+
+    #[inline]
+    pub fn root_pt(&self) -> &PageTable {
+        unsafe { &*self.root_pt }
+    }
+
+    #[inline]
+    pub fn root_pt_mut(&mut self) -> &mut PageTable {
+        unsafe { &mut *self.root_pt }
+    }
+
+    /// Resolve page and offset from the page
+    fn page_lookup(&self, addr: u64) -> Option<PageLookupResult> {
         let mut current_pt = self.root_pt;
         for lvl in (0..5).rev() {
             unsafe {
@@ -69,36 +112,32 @@ impl Memory {
                 match entry.permission() {
                     Permission::Empty => return None,
                     Permission::Node => current_pt = ptr as _,
-                    Permission::Readonly | Permission::Write | Permission::Exec => {
+                    _ if lvl > 2 => return None,
-                        let mut value = MaybeUninit::<Value>::zeroed();
+                    perm => {
-                        core::ptr::copy_nonoverlapping::<u8>(
+                        return Some(PageLookupResult {
-                            entry.ptr() as _,
+                            perm,
-                            value.as_mut_ptr().cast(),
+                            ptr: ptr as _,
-                            1,
+                            size: match lvl {
-                        );
+                                0 => 4096,
-                        return Some(value.assume_init());
+                                1 => 1024_usize.pow(2) * 2,
+                                2 => 4096_usize.pow(3),
+                                _ => unreachable!(),
+                            },
+                            offset: addr as usize & ((1 << 12) - 1),
+                        })
                     }
                 }
             }
         }
-
         None
     }
+}
 
-    /// Store value to an address
+struct PageLookupResult {
-    pub fn store<S: MemAccessSize>(&mut self, addr: u64, value: Value) -> Result<(), ()> {
+    perm: Permission,
-        Err(())
+    ptr: *mut u8,
-    }
+    size: usize,
-
+    offset: usize,
-    #[inline]
-    pub fn root_pt(&self) -> &PageTable {
-        unsafe { &*self.root_pt }
-    }
-
-    #[inline]
-    pub fn root_pt_mut(&mut self) -> &mut PageTable {
-        unsafe { &mut *self.root_pt }
-    }
 }
 
 macro_rules! size_markers {

hbvm/src/vm/mem/paging.rs

@@ -5,7 +5,6 @@ use core::{
     slice::SliceIndex,
 };
 use delegate::delegate;
-use derive_more::{Deref, DerefMut};
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 #[repr(u8)]
@@ -94,14 +93,9 @@ impl Default for PageTable {
     }
 }
 
-/// This byte is special. It has a whole page reserved just for it.
-#[derive(Clone, Copy, PartialEq, Eq, Deref, DerefMut)]
-#[repr(align(4096))]
-pub struct SpecialByte(u8);
-
 #[derive(Clone, Copy)]
-#[repr(C)]
+#[repr(C, align(4096))]
 pub union PtPointedData {
     pub pt: PageTable,
-    pub page: SpecialByte,
+    pub page: u8,
 }