Added formatted print function

7 files changed, 153 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index eb9e863..5954371 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,8 @@ COBJS = src/main.o \
 		src/lib/str.o \
 		src/lib/mem.o \
 		src/lib/math.o \
-		src/lib/conv.o
+		src/lib/conv.o \
+		src/lib/print.o
 CC = cross/opt/bin/i686-elf-gcc
 LD = cross/opt/bin/i686-elf-ld
 AS = nasm
diff --git a/src/lib/conv.c b/src/lib/conv.c
index 89d1786..3bde4ec 100644
--- a/src/lib/conv.c
+++ b/src/lib/conv.c
@@ -114,3 +114,31 @@ char *itoa(int n)
 	strinv(ret);
 	return ret;
 }
+
+char *conv_base(int value, char *result, int base, int is_signed)
+{
+	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);
+
+	if (is_signed && tmp_value < 0)
+		*ptr++ = '-';
+	*ptr-- = '\0';
+	while (ptr1 < ptr) {
+		tmp_char = *ptr;
+		*ptr-- = *ptr1;
+		*ptr1++ = tmp_char;
+	}
+	return result;
+}
diff --git a/src/lib/inc/arg.h b/src/lib/inc/arg.h
new file mode 100644
index 0000000..73e592d
--- /dev/null
+++ b/src/lib/inc/arg.h
@@ -0,0 +1,11 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#ifndef ARG_H
+#define ARG_H
+
+typedef __builtin_va_list va_list;
+#define va_start __builtin_va_start
+#define va_end __builtin_va_end
+#define va_arg __builtin_va_arg
+
+#endif
diff --git a/src/lib/inc/conv.h b/src/lib/inc/conv.h
index 8295756..d878deb 100644
--- a/src/lib/inc/conv.h
+++ b/src/lib/inc/conv.h
@@ -10,4 +10,6 @@ char *htoa(u32 n);
 int htoi(char *str);
 char *itoa(int n);
 
+char *conv_base(int value, char *result, int base, int is_signed);
+
 #endif
diff --git a/src/lib/inc/print.h b/src/lib/inc/print.h
new file mode 100644
index 0000000..1a2419b
--- /dev/null
+++ b/src/lib/inc/print.h
@@ -0,0 +1,13 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+// I may (re)move this in the future // TODO
+
+#ifndef PRINT_H
+#define PRINT_H
+
+#include <arg.h>
+
+int printf(const char *format, ...);
+int vprintf(const char *format, va_list ap);
+int vsprintf(char *str, const char *format, va_list ap);
+
+#endif
diff --git a/src/lib/print.c b/src/lib/print.c
new file mode 100644
index 0000000..9379f68
--- /dev/null
+++ b/src/lib/print.c
@@ -0,0 +1,95 @@
+#include <arg.h>
+#include <conv.h>
+#include <def.h>
+#include <mem.h>
+#include <serial.h>
+#include <str.h>
+
+static void append(char *dest, char *src, int index)
+{
+	for (u32 i = index; i < strlen(src) + index; i++)
+		dest[i] = src[i - index];
+	dest[index + strlen(src)] = 0;
+}
+
+int vsprintf(char *str, const char *format, va_list ap)
+{
+	u8 ready_to_format = 0;
+
+	int i = 0;
+	char buf = 0;
+	char format_buffer[20] = "\0";
+
+	for (; *format; format++) {
+		if (ready_to_format) {
+			ready_to_format = 0;
+
+			if (*format == '%') {
+				str[i] = '%';
+				continue;
+			}
+
+			buf = *format;
+
+			// TODO: Improve this repetitive code
+			if (buf == 's') {
+				char *string = va_arg(ap, char *);
+				append(str, string, i);
+				i = strlen(str);
+			} else if (buf == 'x') {
+				conv_base(va_arg(ap, u32), format_buffer, 16, 0);
+				append(str, format_buffer, i);
+				i = strlen(str);
+			} else if (buf == 'd' || buf == 'i') {
+				conv_base(va_arg(ap, s32), format_buffer, 10, 1);
+				append(str, format_buffer, i);
+				i = strlen(str);
+			} else if (buf == 'u') {
+				conv_base(va_arg(ap, u32), format_buffer, 10, 0);
+				append(str, format_buffer, i);
+				i = strlen(str);
+			} else if (buf == 'o') {
+				conv_base(va_arg(ap, u32), format_buffer, 8, 0);
+				append(str, format_buffer, i);
+				i = strlen(str);
+			} else if (buf == 'b') {
+				conv_base(va_arg(ap, u32), format_buffer, 2, 0);
+				append(str, format_buffer, i);
+				i = strlen(str);
+			} else if (buf == 'c') {
+				str[i] = (char)va_arg(ap, int);
+				i++;
+			}
+		} else {
+			if (*format == '%')
+				ready_to_format = 1;
+			else {
+				str[i] = *format;
+				i++;
+			}
+		}
+
+		format_buffer[0] = '\0';
+	}
+
+	return strlen(str);
+}
+
+int vprintf(const char *format, va_list ap)
+{
+	char buf[1024];
+	memset(buf, 0, 1024);
+	int len = vsprintf(buf, format, ap);
+	serial_print(buf); // TODO: Remove temporary serial print
+	return len;
+}
+
+int printf(const char *format, ...)
+{
+	va_list ap;
+	va_start(ap, format);
+	int len = vprintf(format, ap);
+	va_end(ap);
+
+	return len;
+}
diff --git a/src/main.c b/src/main.c
index 947c0e1..a4b290c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -4,6 +4,7 @@
 #include <def.h>
 #include <interrupts.h>
 #include <keyboard.h>
+#include <print.h>
 #include <serial.h>
 #include <vesa.h>
 
@@ -23,7 +24,7 @@ void main(struct mem_info *mem_info, struct vid_info *vid_info)
 	vesa_fill(terminal_background);
 
 	serial_install();
-	serial_print("hello\n");
+	printf("hello");
 
 	while (1) {
 	};