dd

git-svn-id: https://spexeah.com:8443/svn/Asuro@170 6dbc8c32-bb84-406f-8558-d1cf31a0ab0c

src/contextswitcher.pas

@@ -0,0 +1,16 @@
+{ ************************************************
+  * Asuro
+  * Unit: ContextSwitcher
+  * Description: Switches context between processes
+  *              when preempted by the scheduler.
+  ************************************************
+  * Author: K Morris
+  * Contributors:
+  ************************************************ }
+unit contextswitcher;
+
+interface
+
+implementation;
+
+end.

src/gdt.pas

@@ -35,6 +35,7 @@ var
     gdt_pointer : TGDT_Pointer;
 
 procedure init();
+procedure set_gate(Gate_Number : uint32; Base : uint32; Limit : uint32; Access : uint8; Granularity : uint8);
     
 implementation
 
@@ -71,11 +72,11 @@ begin
     console.writestringln('GDT: INIT START.');
     gdt_pointer.limit := (sizeof(TGDT_Entry) * 5) - 1;
     gdt_pointer.base  := uint32(@gdt_entries);
-    set_gate($00, $00, $00,       $00, $00);
+    set_gate($00, $00, $00,       $00, $00); //OFFSET: 0
-    set_gate($01, $00, $FFFFFFFF, $9A, $CF);
+    set_gate($01, $00, $FFFFFFFF, $9A, $CF); //OFFSET: 8
-    set_gate($02, $00, $FFFFFFFF, $92, $CF);
+    set_gate($02, $00, $FFFFFFFF, $92, $CF); //OFFSET: 16
-    set_gate($03, $00, $FFFFFFFF, $FA, $CF);
+    set_gate($03, $00, $FFFFFFFF, $FA, $CF); //OFFSET: 24
-    set_gate($04, $00, $FFFFFFFF, $F2, $CF);
+    set_gate($04, $00, $FFFFFFFF, $F2, $CF); //OFFSET: 32
     console.writestringln('GDT: FLUSH.');
     flush_gdt(uint32(@gdt_pointer));
     console.writestringln('GDT: INIT END.');

src/kernel.pas

@@ -25,6 +25,7 @@ uses
      vmemorymanager,
      pmemorymanager,
      lmemorymanager,
+     tss,
      scheduler,
      PCI;
  
@@ -64,9 +65,11 @@ begin
      pmemorymanager.init();
      vmemorymanager.init();
      lmemorymanager.init();
-
+     tss.init();
      scheduler.init();
 
+     while true do begin end;
+
      STI;
      isr32.hook(uint32(@bios_data_area.tick_update));
 

src/scheduler.pas

@@ -32,6 +32,9 @@ type
     end;
     PScheduler_Entry = ^TScheduler_Entry;
 
+var
+    Active : Boolean;
+
 procedure init;
 procedure add_task(priority : uint8);
 
@@ -70,9 +73,11 @@ end;
 
 procedure delta(data : void);
 begin
-    Tick:= Tick + 1;
+    If Active then begin
-    If Tick = 0 then context_switch();
+        Tick:= Tick + 1;
-    If (Current_Task^.Delta + (Current_Task^.Priority * Quantum)) <= Tick then context_switch();
+        If Tick = 0 then context_switch();
+        If (Current_Task^.Delta + (Current_Task^.Priority * Quantum)) <= Tick then context_switch();
+    end;
 end;
 
 procedure init;
@@ -85,6 +90,7 @@ begin
     Root_Task^.Next:= void(Root_Task);
     Current_Task:= Root_Task;
     Tick:= 0;
+    Active:= False;
     isr32.hook(uint32(@delta));
     console.writestringln('SCHEDULER: INIT END.');
 end;

src/vmemorymanager.pas

@@ -36,17 +36,42 @@ type
     PPageDirectory = ^TPageDirectory;
 
 var
+    KERNEL_PAGE_DIRECTORY : PPageDirectory;
     PageDirectory : PPageDirectory;
 
 procedure init;
 function new_page(page_number : uint16) : boolean;
 function map_page(page_number : uint16; block : uint16) : boolean;
+function map_page_ex(page_number : uint16; block : uint16; PD : PPageDirectory) : boolean;
 function new_page_at_address(address : uint32) : boolean;
 procedure free_page(page_number : uint16);
 procedure free_page_at_address(address : uint32);
+function new_page_directory : uint32;
+function new_kernel_mapped_page_directory : uint32;
 
 implementation
 
+uses
+    lmemorymanager;
+
+function new_page_directory : uint32;
+begin
+     new_page_directory:= uint32(kalloc(sizeof(TPageDirectory)));
+end;
+
+function new_kernel_mapped_page_directory : uint32;
+var
+    PD : PPageDirectory;
+    i  : uint32;
+
+begin
+    PD:= PPageDirectory(new_page_directory);
+    for i:=KERNEL_PAGE_NUMBER to 1023 do begin
+        PD^[i]:= KERNEL_PAGE_DIRECTORY^[i];
+    end;
+    new_kernel_mapped_page_directory:= uint32(PD);
+end;
+
 function load_current_page_directory : PPageDirectory;
 var
     Directory : uint32;
@@ -67,30 +92,26 @@ var
 begin
     console.writestringln('VMM: INIT BEGIN.');
     PageDirectory:= load_current_page_directory;
+    KERNEL_PAGE_DIRECTORY:= PageDirectory;
     map_page(KERNEL_PAGE_NUMBER + 1, 1);
     map_page(KERNEL_PAGE_NUMBER + 2, 2);
     map_page(KERNEL_PAGE_NUMBER + 3, 3);
     console.writestringln('VMM: INIT END.');
 end;
 
-function map_page(page_number : uint16; block : uint16) : boolean;
+function map_page_ex(page_number : uint16; block : uint16; PD : PPageDirectory) : boolean;
 var
     addr  : ubit20;
     page  : uint16;
-    rldpd : uint32;
 
 begin
-    map_page:= false;
+    map_page_ex:= false;
-    PageDirectory^[page_number].Present:= true;
+    PD^[page_number].Present:= true;
     addr:= block;
-    PageDirectory^[page_number].Address:= addr SHL 10;
+    PD^[page_number].Address:= addr SHL 10;
-    PageDirectory^[page_number].PageSize:= true;
+    PD^[page_number].PageSize:= true;
-    PageDirectory^[page_number].Writable:= true;
+    PD^[page_number].Writable:= true;
-    rldpd:= uint32(PageDirectory) - KERNEL_VIRTUAL_BASE;
+    
-    asm
-        mov eax, rldpd
-        mov CR3, eax
-    end;
     console.writestringln('VMM: New Page Added:');
 
     console.writestring('VMM: - P:');
@@ -107,7 +128,28 @@ begin
     console.writestring(' - ');
     console.writehex(((block+1) SHL 22));
     console.writestringln(']');
-    map_page:= true;
+    map_page_ex:= true;
+end;
+
+function map_page(page_number : uint16; block : uint16) : boolean;
+var
+    addr  : ubit20;
+    page  : uint16;
+    rldpd : uint32;
+
+begin
+    map_page:= false;
+    PageDirectory^[page_number].Present:= true;
+    addr:= block;
+    PageDirectory^[page_number].Address:= addr SHL 10;
+    PageDirectory^[page_number].PageSize:= true;
+    PageDirectory^[page_number].Writable:= true;
+    map_page:= map_page_ex(page_number, block, PageDirectory);
+    rldpd:= uint32(PageDirectory) - KERNEL_VIRTUAL_BASE;
+    asm
+        mov eax, rldpd
+        mov CR3, eax
+    end;
 end;
 
 function new_page(page_number : uint16) : boolean;