VMem & PMem

git-svn-id: https://spexeah.com:8443/svn/Asuro@124 6dbc8c32-bb84-406f-8558-d1cf31a0ab0c

src/kernel.pas

@@ -52,12 +52,13 @@ begin
      isr.init();
      irq.init();
      pmemorymanager.init();
+     vmemorymanager.init();
      scheduler.init();
 
      STI;
      isr32.hook(uint32(@bios_data_area.tick_update));
 
-     z:= 1;
+     {z:= 1;
      while true do begin
         console.writeword(z);
         console.writestring(': ');
@@ -65,11 +66,11 @@ begin
         console.writewordln(uint32(pint));
         if pint = nil then while true do begin end else pint^:= 1234;
         z:=z+1;
-     end;
+     end;}
 
      //drivers
      keyboard.init(keyboard_layout);
-     if PageDirectory[KERNEL_PAGE_NUMBER].Present then begin
+     if PageDirectory^[KERNEL_PAGE_NUMBER].Present then begin
         console.writestringln('!');
      end else begin
         console.writestringln('?');  

src/util.pas

@@ -18,6 +18,7 @@ uses
 
 procedure CLI();
 procedure STI();
+procedure GPF();
 function hi(b : uint8) : uint8;
 function lo(b : uint8) : uint8;
 function switchendian(b : uint8) : uint8;
@@ -61,6 +62,11 @@ asm
     STI
 end;
 
+procedure GPF(); assembler;
+asm
+    INT 13
+end;
+
 function switchendian(b : uint8) : uint8; [public, alias: 'util_switchendian'];
 begin
      switchendian:= (lo(b) SHL 4) OR hi(b);

src/vmemorymanager.pas

@@ -2,22 +2,12 @@ unit vmemorymanager;
 
 interface
 
-type
-    {PPageTableEntry = ^TPageTableEntry;
-    TPageTableEntry = bitpacked record
-        Present, 
-        Writable, 
-        UserMode, 
-        WriteThrough,
-        NotCacheable, 
-        Accessed, 
-        Dirty, 
-        AttrIndex,
-        GlobalPage: Boolean;
-        Available: UBit3;
-        FrameAddress: UBit20;
-    end;}
+uses
+    util,
+    pmemorymanager,
+    console;
 
+type
     PPageDirEntry = ^TPageDirEntry;
     TPageDirEntry = bitpacked record
         Present, 
@@ -30,15 +20,93 @@ type
         PageSize,
         GlobalPage: Boolean;
         Available: UBit3;
-        TableAddress: UBit20;
+        Address: UBit20;
     end;
 
-    TPageDirectory = Array[1..1024] of TPageDirEntry;
+    TPageDirectory = Array[0..1023] of TPageDirEntry;
     PPageDirectory = ^TPageDirectory;
 
-Var
-    PageDirectory : TPageDirectory; external name '_PageDirectory';
+var
+    PageDirectory : PPageDirectory;
+
+procedure init;
+function new_page(page_number : uint16) : boolean;
+function new_page_at_address(address : uint32) : boolean;
+procedure free_page(page_number : uint16);
 
 implementation
 
+function load_current_page_directory : PPageDirectory;
+var
+    Directory : uint32;
+
+begin
+    asm
+        MOV EAX, CR3
+        MOV Directory, EAX
+    end;
+    Directory:= Directory + KERNEL_VIRTUAL_BASE;
+    load_current_page_directory:= PPageDirectory(Directory);
+end;
+
+procedure init;
+var
+    i : uint32;
+
+begin
+    console.writestringln('VMM: INIT BEGIN.');
+    PageDirectory:= load_current_page_directory;
+    console.writestringln('VMM: INIT END.');
+end;
+
+function new_page(page_number : uint16) : boolean;
+var
+    block : uint16;
+    page  : uint16;
+
+begin
+    new_page:= false;
+    if PageDirectory^[block].Present then exit;
+    if PageDirectory^[block].Reserved then exit;
+    block:= pmemorymanager.newblock(uint32(PageDirectory));
+    if block < 2 then begin
+        GPF;
+        exit;
+    end else begin
+        PageDirectory^[block].Present:= true;
+        PageDirectory^[block].Address:= block;
+        PageDirectory^[block].PageSize:= true;
+        new_page:= true;
+    end;
+end;
+
+function new_page_at_address(address : uint32) : boolean;
+var
+    page_number : uint16;
+
+begin
+    page_number:= address SHR 22;
+    new_page_at_address:= new_page(page_number);
+end;
+
+procedure free_page(page_number : uint16);
+begin
+    if PageDirectory^[page_number].Present then begin
+        asm
+            invlpg [page_number]
+        end;    
+    end else begin
+        GPF;
+    end;
+end;
+
+function free_page_at_address(address : uint32);
+var
+    page_number : uint16;
+
+begin
+    page_number:= address SHR 22;
+    free_page(page_number);
+end;
+
 end.