Implemented initial printk. Added multiboot support.

kernel/brados.c

@@ -1,36 +1,20 @@
 #include <stddef.h>
+#include <stdint.h>
 
+#include <brados/printk.h>
 #include <brados/string.h>
 #include <video/vga.h>
+#include <multiboot.h>
 
 // Make sure we are using the right compiler
 #if defined(__linux__)
 #error "You are using the wrong compiler."
 #endif
 
-// Test various VGA functionality
-void vgaTests(struct vgastate *term)
-{
-	// Test line wrapping
-	term_writeStr(term, "Welcome to the desert of the real. I thought what I'd do was I'd pretend I was one of those deaf mutes.\n\n");
-	
-	// Test colors
-	term_setColor(term, make_color(VGA_COLOR_BLACK, VGA_COLOR_WHITE));
-	term_writeStr(term, "This text should be inverse.\n");
-	term_setColor(term, make_color(VGA_COLOR_LIGHT_BLUE, VGA_COLOR_GREEN));
-	term_writeStr(term, "This text should be colorful.\n\n");
-	
-	// Test scrolling
-	term_setColor(term, make_color(VGA_COLOR_LIGHT_GREY, VGA_COLOR_BLACK));
-	for (size_t i = 0; i < 20; i++) {
-		term_writeStr(term, "Printing some lines.\n");
-		for (volatile size_t j = 0; j < 100000000; j++);
-	}
-}
-
 // Main kernel function
-void brados_main()
+void brados_main(uint32_t multiMagic, uint32_t multiAddr)
 {
+	// Initialize VGA terminal
 	struct vgastate term;
 	term_init(&term);
 	
@@ -38,7 +22,21 @@ void brados_main()
 	term_writeStr(&term, "Welcome to BRaDOS!\n");
 	term_writeStr(&term, "written by L. Bradley LaBoon\n\n");
 	
-	vgaTests(&term);
+	// VGA tests
+	//term_test(&term);
 	
+	// Get multiboot info
+	printk(&term, "Multiboot value: %x\n", multiMagic);
+	if (multiMagic != 0x2BADB002) {
+		term_writeStr(&term, "Error! Multiboot header not present. Quitting.\n");
+		return;
+	}
+	printk(&term, "Multiboot address: %x\n", multiAddr);
+	struct multiboot_header *multiHead = (struct multiboot_header *) multiAddr;
+	printk(&term, "Flags: %x\nMem Lower: %x\nMem Upper: %x\n", multiHead->flags, multiHead->mem_lower, multiHead->mem_upper);
+	char *bootName = (char *) multiHead->boot_loader_name;
+	printk(&term, "Boot loader: %s\n\n", bootName);
+	
+	// Done
 	term_writeStr(&term, "Done.");
 }

kernel/printk.c

@@ -0,0 +1,76 @@
+#include <stdarg.h>
+#include <stddef.h>
+
+#include <brados/printk.h>
+#include <brados/string.h>
+#include <video/vga.h>
+
+const char *BASE16 = "0123456789ABCDEF";
+
+static int printNum(struct vgastate *term, unsigned int num, unsigned int base)
+{
+	int numPrinted = 0;
+	int digit = num % base;
+	if (num >= base)
+		numPrinted += printNum(term, num / base, base);
+	term_putChar(term, BASE16[digit]);
+	numPrinted++;
+	return numPrinted;
+}
+
+int printk(struct vgastate *term, const char *fmt, ...)
+{
+	int numPrinted = 0;
+	va_list args;
+	va_start(args, fmt);
+	
+	for (size_t i = 0; i < strlen(fmt); i++) {
+		if (fmt[i] == '%') {
+			int d;
+			unsigned int x;
+			char *s;
+			switch (fmt[i+1]) {
+			case '%':
+				term_putChar(term, '%');
+				numPrinted++;
+				break;
+			case 'c':
+				term_putChar(term, (char) va_arg(args, int));
+				numPrinted++;
+				break;
+			case 'i':
+				d = va_arg(args, int);
+				if (d < 0) {
+					term_putChar(term, '-');
+					numPrinted++;
+					d *= -1;
+				}
+				numPrinted += printNum(term, (unsigned int) d, 10);
+				break;
+			case 's':
+				s = va_arg(args, char *);
+				term_writeStr(term, s);
+				numPrinted += strlen(s);
+				break;
+			case 'x':
+				x = va_arg(args, unsigned int);
+				term_writeStr(term, "0x");
+				numPrinted += 2;
+				numPrinted += printNum(term, x, 16);
+				break;
+			default:
+				term_putChar(term, fmt[i+1]);
+				numPrinted++;
+				break;
+			}
+			
+			i++;
+		} else {
+			term_putChar(term, fmt[i]);
+			numPrinted++;
+		}
+	}
+	
+	va_end(args);
+	return numPrinted;
+}