Don't try to put pixel off-screen

src/framebuffer.c

@@ -0,0 +1,24 @@
+#include "framebuffer.h"
+
+static unsigned long fb_address;
+static unsigned long fb_pitch;
+static unsigned short fb_width, fb_height;
+static unsigned char fb_bpp, fb_bytespp;
+static unsigned char fb_rpos, fb_bpos, fb_gpos;
+
+void initfb(unsigned long addr, unsigned short w, unsigned short h, unsigned char bpp, unsigned long pitch, unsigned char rpos, unsigned char gpos, unsigned char bpos) {
+	fb_address = addr;
+	fb_pitch = pitch;
+	fb_width = w;
+	fb_height = h;
+	fb_bpp = bpp;
+	fb_bytespp = bpp/8;
+	fb_rpos = rpos;
+	fb_gpos = gpos;
+	fb_bpos = bpos;
+}
+
+void putpixel(unsigned short x, unsigned short y, unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+	if (x>fb_width || y> fb_height) return;
+	*((unsigned long *)(fb_address + y*fb_pitch + x*fb_bytespp)) = r<<fb_rpos | g<<fb_gpos | b<<fb_bpos;
+}

src/framebuffer.h

@@ -0,0 +1,7 @@
+#ifndef _FRAMEBUFFER_H
+#define _FRAMEBUFFER_H 1
+
+void initfb(unsigned long addr, unsigned short w, unsigned short h, unsigned char bpp, unsigned long pitch, unsigned char rpos, unsigned char gpos, unsigned char bpos);
+void putpixel(unsigned short x, unsigned short y,  unsigned char r, unsigned char g, unsigned char b, unsigned char a);
+
+#endif

src/kernel.c

@@ -1,5 +1,5 @@
 #include "multiboot.h"
-#include "vga.h"
+#include "framebuffer.h"
 #include "serial.h"
 #include "xtoa.h"
 
@@ -18,90 +18,58 @@ void kmain (unsigned int mbootmagick, multiboot_info_t* mbootinfo) {
     outb(0x3D4, 0x0A);
     outb(0x3D5, 0x20);
 
-    //cls();
-    vga_init(VGA_COLOR_BLACK, VGA_COLOR_GRAY);
-
-    vga_write_line("=== KoalemOS ===");
-
-    if (serial_init() > 0) {
-        vga_write_line_color("Serial initialization failed", VGA_COLOR_BLACK,
-                             VGA_COLOR_ORANGE);
-    } else {
-        vga_write_line("\nInitialized serial.");
-        serial_write_string("\n=== KoalemOS ===\n");
-    }
-    vga_write("Checking multiboot loader: ");
+    int serial_initialized = serial_init();
+    serial_write_string("\n=== KoalemOS ===\n");
 
     // Check multiboot header
     if (mbootmagick != MULTIBOOT_BOOTLOADER_MAGIC) {
-        vga_write_color("INVALID MAGIC", VGA_COLOR_BLACK, VGA_COLOR_RED);
         return;
     }
-    if (mbootinfo->flags & MULTIBOOT_INFO_BOOT_LOADER_NAME)
-        vga_write((char *)mbootinfo->boot_loader_name);
-    else
-        vga_write_color("Unknown", VGA_COLOR_BLACK, VGA_COLOR_ORANGE);
 
-    vga_write("\nMultiboot flags: ");
-    vga_write(itoa(mbootinfo->flags, 2));
+    serial_write_string("\nMultiboot flags: ");
+    serial_write_string(itoa(mbootinfo->flags, 2));
 
     serial_write_string("\nMultiboot flags: ");
     serial_write_string(itoa(mbootinfo->flags, 2));
 
     // Check videomode
     if (mbootinfo->flags & MULTIBOOT_INFO_VBE_INFO) {
-        vga_write("\nVBE Mode: 0x");
-        vga_write(itoa(mbootinfo->vbe_mode, 16));
-        serial_write_string("\nVBE Mode: 0x");
-        serial_write_string(itoa(mbootinfo->vbe_mode, 16));
+      serial_write_string("\nVBE Mode: 0x");
+      serial_write_string(itoa(mbootinfo->vbe_mode, 16));
     }
-    if (mbootinfo->flags & MULTIBOOT_INFO_FRAMEBUFFER_INFO) {
-        vga_write("\nFramebuffer: ");
-        serial_write_string("\nFramebuffer: ");
-        vga_write("address: 0x");
-        serial_write_string("\n  Address: 0x");
-        vga_write(ultoa(mbootinfo->framebuffer_addr, 16));
-        serial_write_string(ultoa(mbootinfo->framebuffer_addr, 16));
 
-        serial_write_string("\n  Dimensions: ");
-        serial_write_string(itoa(mbootinfo->framebuffer_width, 10));
-        serial_write_string("X");
-        serial_write_string(itoa(mbootinfo->framebuffer_height, 10));
-        serial_write_string("x");
-        serial_write_string(itoa(mbootinfo->framebuffer_bpp, 10));
-        serial_write_string("\n  Pitch: ");
-        serial_write_string(itoa(mbootinfo->framebuffer_pitch, 10));
-        serial_write_string("\n  RPos:");
-        serial_write_string(itoa(mbootinfo->framebuffer_red_field_position, 10));
-        serial_write_string("\n  GPos:");
-        serial_write_string(itoa(mbootinfo->framebuffer_green_field_position, 10));
-        serial_write_string("\n  BPos:");
-        serial_write_string(itoa(mbootinfo->framebuffer_blue_field_position, 10));
+    if (!(mbootinfo->flags & MULTIBOOT_INFO_FRAMEBUFFER_INFO)) {
+      serial_write_string("\nVideo info not available");
+      return;
+    }
 
-        unsigned long *vmem;
-        int i;
-        for (i = 0; i < mbootinfo->framebuffer_height; i++) {
-          vmem = mbootinfo->framebuffer_addr + i*mbootinfo->framebuffer_pitch + i*(mbootinfo->framebuffer_bpp/8);
-          *vmem = 0xff<<mbootinfo->framebuffer_red_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_red_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_red_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_red_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_green_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_green_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_green_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_green_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_blue_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_blue_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_blue_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
-          *vmem = 0xff<<mbootinfo->framebuffer_blue_field_position;((char *)vmem)+=mbootinfo->framebuffer_bpp/8;
+    serial_write_string("\nFramebuffer: ");
+    serial_write_string("\n  Address: 0x");
+    serial_write_string(ultoa(mbootinfo->framebuffer_addr, 16));
+
+    serial_write_string("\n  Dimensions: ");
+    serial_write_string(itoa(mbootinfo->framebuffer_width, 10));
+    serial_write_string("X");
+    serial_write_string(itoa(mbootinfo->framebuffer_height, 10));
+    serial_write_string("x");
+    serial_write_string(itoa(mbootinfo->framebuffer_bpp, 10));
+    serial_write_string("\n  Pitch: ");
+    serial_write_string(itoa(mbootinfo->framebuffer_pitch, 10));
+    serial_write_string("\n  RPos:");
+    serial_write_string(itoa(mbootinfo->framebuffer_red_field_position, 10));
+    serial_write_string("\n  GPos:");
+    serial_write_string(itoa(mbootinfo->framebuffer_green_field_position, 10));
+    serial_write_string("\n  BPos:");
+    serial_write_string(itoa(mbootinfo->framebuffer_blue_field_position, 10));
+
+    initfb(mbootinfo->framebuffer_addr, mbootinfo->framebuffer_width, mbootinfo->framebuffer_height, mbootinfo->framebuffer_bpp, mbootinfo->framebuffer_pitch, mbootinfo->framebuffer_red_field_position, mbootinfo->framebuffer_green_field_position, mbootinfo->framebuffer_blue_field_position);
+
+    int x, y;
+    for (y=0; y<mbootinfo->framebuffer_height;y++) {
+      for (x=0; x<mbootinfo->framebuffer_width;x++) {
+        putpixel(x, y, 0, 255*x/mbootinfo->framebuffer_width, 255*y/mbootinfo->framebuffer_height, 0xff);
       }
-
-
-    } else {
-        vga_write_color("\nVideo info not available", VGA_COLOR_BLACK, VGA_COLOR_RED);
-        serial_write_string("\nVideo info not available");
-        return;
     }
-    vga_write_line("\nExecution finished, halting...");
+
     serial_write_string("\nExecution finished, halting...");
 }

src/xtoa.c

@@ -24,6 +24,30 @@ char* itoa(int value, int base) {
     }
     return result;
 }
+char* uitoa(unsigned int value, int base) {
+    char* result;
+
+    // check that the base if valid
+    if (base < 2 || base > 36) { *result = '\0'; return result; }
+
+    char* ptr = result, *ptr1 = result, tmp_char;
+    int tmp_value;
+
+    do {
+        tmp_value = value;
+        value /= base;
+        *ptr++ = "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz" [35 + (tmp_value - value * base)];
+    } while ( value );
+
+
+    *ptr-- = '\0';
+    while(ptr1 < ptr) {
+        tmp_char = *ptr;
+        *ptr--= *ptr1;
+        *ptr1++ = tmp_char;
+    }
+    return result;
+}
 char* ltoa(long value, int base) {
     char* result;
 

src/xtoa.h

@@ -2,6 +2,7 @@
 #define HEADER_XTOA
 
 char* itoa(int value, int base);
+char* uitoa(unsigned int value, int base);
 char* ltoa(long value, int base);
 char* ultoa(unsigned long value, int base);