Implemented initial printk. Added multiboot support.

2014-01-31 16:12:04 -05:00
parent 3b27d50edb
commit f23f3a8a8d
12 changed files with 257 additions and 38 deletions
--- a/kernel/printk.c
+++ b/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;
+}