Made screen.h use correct resolution instead of assuming

include/graphics.h

@@ -18,9 +18,9 @@
 #define rgb(r,g,b) ( ((r) << 16 | (g) << 8 | (b)) & 0x00ffffff )
 
 void drawPixel(int32_t x, int32_t y, uint32_t color) {
-    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
     
-    uint32_t offset = (y * WIDTH) + x;
+    uint32_t offset = (y * gfxMode->xRes) + x;
     vidmem[offset] = color;
 }
 
@@ -96,9 +96,9 @@ void drawCircle(int32_t x, int32_t y, uint16_t radius, uint32_t color) {
 
 // Recursive (may need large stack)
 void boundaryFill(int32_t x, int32_t y, uint32_t fillColor, uint32_t boundaryColor) {
-    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
 
-    uint32_t offset = y * WIDTH + x;
+    uint32_t offset = y * gfxMode->xRes + x;
 
     if (vidmem[offset] != fillColor && vidmem[offset] != boundaryColor) {
         vidmem[offset] = fillColor;

include/screen.h

@@ -4,24 +4,80 @@
 #include "stdint.h"
 
 #define MODE_INFO_BLOCK 0x5000
-#define WIDTH 1920
-#define HEIGHT 1080
 #define BG_COLOR 0xff010b17
 #define FG_COLOR 0xffebddf4
 
+typedef struct modeInfoBlock_s {
+    // Required by all VBE revisions
+    uint16_t modeAttr;
+    uint8_t windowAAtrr;
+    uint8_t windowBAttr;
+    uint16_t windowGranularity;
+    uint16_t windowSize;
+    uint16_t windowASegment;
+    uint16_t windowBSegment;
+    uint32_t windowFunctionPtr;
+    uint16_t bytesPerScanline;
+
+    // Required by VBE 1.2+
+    uint16_t xRes;
+    uint16_t yRes;
+    uint8_t xCharSize;
+    uint8_t yCharSize;
+    uint8_t planeCount;
+    uint8_t bpp;
+    uint8_t bankCount;
+    uint8_t memoryModel;
+    uint8_t bankSize;
+    uint8_t imagePageCount;
+    uint8_t reserved1;
+
+    // Direct color fields
+    uint8_t redMaskSize;
+    uint8_t redFieldPos;
+    uint8_t greenMaskSize;
+    uint8_t greenFieldPos;
+    uint8_t blueMaskSize;
+    uint8_t blueFieldPos;
+    uint8_t reservedMaskSize;
+    uint8_t reservedFieldPos;
+    uint8_t directColorModeInfo;
+
+    // Required by VBE 2.0+
+    uint32_t physicalBasePtr;
+    uint32_t reserved2;
+    uint16_t reserved3;
+
+    // Required by VBE 3.0+
+    uint16_t linearBytesPerScanline;
+    uint8_t bankImagePageCount;
+    uint8_t linearImagePageCount;
+    uint8_t linearRedMaskSize;
+    uint8_t linearRedFieldPos;
+    uint8_t linearGreenMaskSize;
+    uint8_t linearGreenFieldPos;
+    uint8_t linearBlueMaskSize;
+    uint8_t linearBlueFieldPos;
+    uint8_t linearReservedMaskSize;
+    uint8_t linearReservedFieldPos;
+    uint32_t maxPixelClock;
+
+    uint8_t reserved4[190];
+} __attribute__ ((packed)) modeInfoBlock_t;
+
 struct cursor_s {
     uint32_t x;
     uint32_t y;
 };
 
 static char* font = (char*)0x6000;
-
 static struct cursor_s cursor = { 0, 0 };
+static modeInfoBlock_t* gfxMode = (modeInfoBlock_t*)MODE_INFO_BLOCK;
 
 // TODO: Probably make the font bigger in a better way, but this works for now
 void putcAt(unsigned char c, uint32_t x, uint32_t y) {
-    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
-    uint32_t offset = (WIDTH * y * 16 + x * 8) * 2;
+    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
+    uint32_t offset = (gfxMode->xRes * y * 16 + x * 8) * 2;
 
     char* bitmap = &font[((c % 128) - 1) * 16];
     for (uint8_t i = 0; i < 32; i++) { // Rows (16*2 since we draw font 2x larger)
@@ -34,7 +90,7 @@ void putcAt(unsigned char c, uint32_t x, uint32_t y) {
             }
         } 
 
-        offset += WIDTH;
+        offset += gfxMode->xRes;
     }
 }
 
@@ -67,10 +123,10 @@ void print(const char* str) {
 }
 
 void clear() {
-    uint32_t* vidmem = *(uint32_t**)(MODE_INFO_BLOCK + 40);
+    uint32_t* vidmem = (uint32_t*)gfxMode->physicalBasePtr;
 
     size_t i = 0;
-    while (i < WIDTH*HEIGHT) {
+    while (i < gfxMode->xRes * gfxMode->yRes) {
         vidmem[i] = BG_COLOR; // #1f2937
         i++;
     }

src/stage2.asm

@@ -252,7 +252,6 @@ protected_start:
     mov esi, modeInfoBlock
     mov edi, 0x5000 ; Destination
     mov ecx, 64 ; 64 * 4 = 256B (size of modeInfoBlock)
-
     rep movsd
 
     ; Perform The far jump
@@ -360,9 +359,9 @@ modeInfoBlock:
     .directColorModeInfo: db 0
 
 ;; Required by VBE 2.0+
-    .physicalAddressPtr: dd 0
-    .reserved2: db 0
-    .reserved3: db 0
+    .physicalBasePtr: dd 0
+    .reserved2: dd 0
+    .reserved3: dw 0
 
 ;; Required by VBE 3.0+
     .linearBytesPerScanline: dw 0

todo.txt

@@ -3,7 +3,7 @@
 - [x] Multistage Bootloader
 - [ ] Bootloader reads filetable to find files
 - [ ] Makefile refactorin'
-- [x] Write down where stuff is in memory 
+- [x] Write down where stuff is in memory (in notes.txt)
 - [ ] "Text" mode (not actually)
     - [ ] Scrolling
     - [ ] Scroll-back
@@ -15,6 +15,7 @@
     - [x] Larger text size
     - [ ] Variable text size :)
     - [ ] Make output overflow go to next line
+    - [ ] More fonts
 - [x] Graphics
     - [?] Enter/exit a "graphics" mode (idk if we need this)
     - [x] Pixel drawing