Added some functions, did some reorganizing.

kttools.h/c is a lib for converting types (only currently contains
i_to_str).

Also added a printf for i/o.

include/kio.h

@@ -1,8 +1,9 @@
-#ifndef KERNIO_H
-#define KERNIO_H
-#define VGA_GRID_COLS 79
+#ifndef KIO_H
+#define KIO_H
+#define VGA_GRID_COLS 80
 #define VGA_GRID_ROWS 25
 #include <stdint.h>
+#include <stdarg.h>
 
 /*
  * CONSTANTS AND VARIABLES
@@ -29,7 +30,8 @@ void vga_putc(char c);
 void vga_set_attributes(uint8_t attributes);
 void vga_print(const char* out);
 void vga_println(const char* out);
-
-
+void vga_printhex(uint32_t out);
+void vga_prindec(uint32_t out);
+void vga_printf(const char* fmt, ...);
 
 #endif

include/kttools.h

@@ -0,0 +1,7 @@
+#ifndef KTTOOLS_H
+#define KTTOOLS_H
+#include <stdint.h>
+
+void i_to_str(uint32_t num, char* buf, int size, int radix);
+
+#endif

src/kernio.c

@@ -1,57 +0,0 @@
-#include "kernio.h"
-#include <stddef.h>
-
-/*
- * VARS
- */
-
-int cursor_col = 0;
-int cursor_row = 0;
-volatile uint16_t* const vga_buffer = (uint16_t*)0xB8000;
-uint16_t vga_attributes = 0x0F00;
-
-void vga_clear() {
-	for (int col = 0; col < VGA_GRID_COLS; col ++) {
-		for (int row = 0; row < VGA_GRID_ROWS; row ++) {
-            //works out to iterating every cell
-			const size_t index = (VGA_GRID_COLS * row) + col;
-            //vga buffer looks something like xxxxyyyyzzzzzzzz
-            //x=bg color
-            //y=fg color
-            //c=character to use
-            //Therefore, to write, we just take our color data and tack on the character to the end.
-			vga_buffer[index] = vga_attributes | ' '; //blank out
-		}
-	}
-}
-
-void vga_putc(char c)
-{
-    //Check for some freaky escape character first
-    if(c == '\n') {
-        cursor_col = 0;
-        cursor_row = (cursor_row + 1) % 25;
-        return;
-    }
-        //Calculate where in the vga buffer to put the character
-		const size_t index = (VGA_GRID_COLS * cursor_row) + cursor_col;
-        //VGA buffer cell consists of the first half attributes, second half character
-		vga_buffer[index] = vga_attributes | c;
-		cursor_col++;
-}	
-
-void vga_set_attributes(uint8_t attributes) {
-     vga_attributes = ((uint16_t)attributes) << 8;
-}
-
-
-void vga_print(const char* out)
-{
-	for (int i = 0; out[i] != '\0'; i++)
-        vga_putc(out[i]);
-}
-
-void vga_println(const char* out) {
-    vga_print(out);
-    vga_print("\n");
-}

src/kio.c

@@ -1,4 +1,5 @@
 #include "kio.h"
+#include "kttools.h"
 #include <stddef.h>
 
 /*
@@ -34,7 +35,8 @@ void vga_putc(char c)
     //Check for some freaky escape character first
     if(c == '\n') {
         cursor_col = 0;
-        cursor_row = (cursor_row + 1) % 25;
+        //mod implements wraparound
+        cursor_row = (cursor_row + 1) % (VGA_GRID_ROWS-1);
         return;
     }
         //Calculate where in the vga buffer to put the character
@@ -49,8 +51,7 @@ void vga_set_attributes(uint8_t attributes) {
 }
 
 
-void vga_print(const char* out)
-{
+void vga_print(const char* out) {
 	for (int i = 0; out[i] != '\0'; i++)
         vga_putc(out[i]);
 }
@@ -59,3 +60,41 @@ void vga_println(const char* out) {
     vga_print(out);
     vga_print("\n");
 }
+
+void vga_printhex(uint32_t out) {
+    char buff[9];
+    i_to_str(out, buff, 9, 0x10);
+    vga_print(buff);
+}
+
+void vga_printdec(uint32_t out) {
+    char buff[11];
+    i_to_str(out, buff, 11, 10);
+    vga_print(buff);
+}
+
+void vga_printf(const char* fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+    
+    while(*fmt) {
+        if(*fmt == '%') {
+            fmt++;
+            switch(*fmt) {
+                case 'X':
+                    vga_print("0x");
+                case 'x':    
+                    vga_printhex(va_arg(args,uint32_t));
+                    break;
+                case 'd':
+                    vga_printdec(va_arg(args,uint32_t));
+                    break;
+
+            }
+        } else {
+            vga_putc(*fmt);
+        }
+        fmt++;
+    }
+
+}

src/kttools.c

@@ -28,16 +28,16 @@
  *  @return No return value
  *
  */
-void i_to_str(uint32_t num, char* buf, int size) {
+void i_to_str(uint32_t num, char* buf, int size, int radix) {
     //null terminate the string
     buf[--size] = '\0';
     while(size > 0 && (num) != 0){
-        int isolated_num = num % 0x10;
+        int isolated_num = num % radix;
         if(isolated_num > 9){
             isolated_num+=7;
         }
         buf[--size] = '0' + isolated_num;
-        num/=0x10;
+        num/=radix;
     }
 
     //now shift the whole thing to the left

src/main.c

@@ -20,10 +20,19 @@ void kern_main(uint32_t multiboot_magic, multiboot_info_t* multiboot_info)
     //wipe the screen
 	vga_clear();
 
-	//IT IS TIME. TO PRINT.
-    char lol[9];
-    i_to_str(multiboot_info->mem_upper, lol, 9); 
+	//We're going to use this buffer as our 8char hex representation for reading mem
+
+    vga_printf("Entry eax:%X\n", multiboot_magic);
+
+    if(multiboot_magic != 0x2BADB002) {
+        vga_println("Bootloader not multiboot1 compliant! Needed for mmap, etc. Can't work without it, kthxbye!");
+        return;
+    } else {
+        vga_println("Multiboot detected! Continuing...");
+    }
+
+    vga_printf("MEM_LOWER:%X\n", multiboot_info->mem_lower);
+    vga_printf("MEM_UPPER:%X\n", multiboot_info->mem_upper);
         
-	vga_println(lol);
 }