From 1f57e99720c4bc5e3e27a88ff469cef43c202a43 Mon Sep 17 00:00:00 2001
From: Aleksa Vučković <aleksav013@gmail.com>
Date: Wed, 29 Jun 2022 01:52:48 +0200
Subject: HigherHalf

---
 src/c/kernel.c     |  2 +-
 src/c/paging.c     | 24 ++++++++++++++++--------
 src/c/shell/game.c |  8 ++++----
 src/c/vga.c        |  3 ++-
 4 files changed, 23 insertions(+), 14 deletions(-)

(limited to 'src/c')

diff --git a/src/c/kernel.c b/src/c/kernel.c
index a5dc31a..9692b32 100644
--- a/src/c/kernel.c
+++ b/src/c/kernel.c
@@ -14,7 +14,7 @@ void kernel_main(void)
     init_timer(50);
     init_keyboard();
     kheapinit();
-    kheapaddblock(0x00200000, 0x00100000, 16);
+    kheapaddblock(0xC0700000, 0x00100000, 16);
 
     terminal_initialize();
     prompt();
diff --git a/src/c/paging.c b/src/c/paging.c
index 4aba4af..0a4c01f 100644
--- a/src/c/paging.c
+++ b/src/c/paging.c
@@ -3,6 +3,7 @@
 
 extern void loadPageDirectory(uint32_t*);
 extern void enablePaging(void);
+extern void flushPaging(void);
 
 uint32_t page_directory[1024] __attribute__((aligned(4096)));
 
@@ -23,11 +24,6 @@ uint32_t page_table[1024][1024] __attribute__((aligned(4096)));
 
 void set_pt(size_t num,uint32_t address)
 {
-    // holds the physical address where we want to start mapping these pages
-    // to.
-    // in this case, we want to map these pages to the very beginning of
-    // memory.
-
     //we will fill all 1024 entries in the table, mapping 4 megabytes
     for(size_t i=0;i<1024;i++)
     {
@@ -37,14 +33,26 @@ void set_pt(size_t num,uint32_t address)
         // attributes: supervisor level, read/write, present.
     }
 
-    page_directory[num] = ((uint32_t)page_table[num]) | 3;
+    page_directory[num] = ((uint32_t)page_table[num] - 0xC0000000) | 3;
     // attributes: supervisor level, read/write, present
 }
 
+void empty_pt(size_t num)
+{
+    for(size_t i=0;i<1024;i++)
+    {
+        page_table[num][i] = 0;
+    }
+
+    page_directory[num] = 0x00000002;
+}
+
 void set_paging(void)
 {
     set_pd();
-    for(size_t i=0;i<1024;i++) set_pt(i,0x00400000 * i); // all 4GB mapped
+    set_pt(768,0x00000000); // maps 0x00000000 to 0xC0000000
+    set_pt(769,0x00400000); // maps 0x00400000 to 0xC0400000
+    set_pt(832,0x000B8000); // maps 0x000B8000 to 0xD0000000
     loadPageDirectory(page_directory);
-    enablePaging();
+    flushPaging();
 }
diff --git a/src/c/shell/game.c b/src/c/shell/game.c
index ce7793b..9e7323e 100644
--- a/src/c/shell/game.c
+++ b/src/c/shell/game.c
@@ -56,8 +56,8 @@ void game_keyboard_handler(uint16_t keycode)
 
 void game_init(void)
 {
-    x=VGA_WIDTH/2;
-    y=VGA_HEIGHT/2;
+    x=(uint16_t)VGA_WIDTH/2;
+    y=(uint16_t)VGA_HEIGHT/2;
     game_time=0;
     game_tick=0;
     duzina=1;
@@ -80,7 +80,7 @@ void game_timer_handler()
         {
             case 1:
                 if(y>0) y--;
-                else y=VGA_HEIGHT-1;
+                else y=(uint16_t)VGA_HEIGHT-1;
                 break;
             case 2:
                 if(y<VGA_HEIGHT-1) y++;
@@ -88,7 +88,7 @@ void game_timer_handler()
                 break;
             case 3:
                 if(x>0) x--;
-                else x=VGA_WIDTH-1;
+                else x=(uint16_t)VGA_WIDTH-1;
                 break;
             case 4:
                 if(x<VGA_WIDTH-1) x++;
diff --git a/src/c/vga.c b/src/c/vga.c
index 84eb538..4e20745 100644
--- a/src/c/vga.c
+++ b/src/c/vga.c
@@ -27,7 +27,8 @@ void terminal_initialize(void)
     terminal_row=0;
     terminal_column=0;
     set_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK);
-    terminal_buffer=(uint16_t*) 0xB8000;
+    //terminal_buffer=(uint16_t*) 0xC00B8000;
+    terminal_buffer=(uint16_t*) 0xD0000000;
     for(size_t y=0;y<VGA_HEIGHT;y++)
     {
         for(size_t x=0;x<VGA_WIDTH;x++)
-- 
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