Merge pull request #29 from E-Almqvist/dev

String Library & Memory

Makefile

@@ -1,5 +1,5 @@
-C_SOURCES = $(wildcard kernel/*.c drivers/*.c)
+C_SOURCES = $(wildcard kernel/*.c drivers/*.c lib/*.c)
-HEADERS = $(wildcard kernel/*.h drivers/*.h)
+HEADERS = $(wildcard kernel/*.h drivers/*.h lib/*.h)
 OBJ = $(C_SOURCES:.c=.o)
 
 all: os-image

TODO.md

@@ -1,6 +1,11 @@
 # TO DO 
- - Refactor the VGA driver
+ - Malloc
- - Finish the book!
+ - String Library
+ 	
+	- Concat
+	- Format
+
+ - Scrolling
  - Multiboot support (for grub etc)
  - Rendering (VGA) 
  - User input (Keyboard)

drivers/vga.c

@@ -50,7 +50,7 @@ void set_cursor_pos(unsigned int col, unsigned int row) {
 void clear_screen() {
 	for( int c = 0; c < MAX_COLS; c++ )
 		for( int r = 0; r < MAX_ROWS; r++ )
-			writechar(0x20, c, r, 0xf0);
+			writechar(0x20, c, r, 0x0f);
 }
 
 /*

kernel/kernel.c

@@ -1,15 +1,18 @@
 #include "../drivers/vga.h"
+#include "../lib/str.h"
+#include "../lib/strf.h"
 
 void main() {
 	vga_init(); 	// Initialize the screen first
 			// i.e. clear the screen et cetera.
 
 	set_cursor_pos(28, 2);
-	print("eOS Version 0.1 2021", 0xf0);
+	print("eOS Version 0.1 2021", 0x0f);
 
-	/*
+
+	char* strbuf = "Hello";
+	char* str2 = "World!";
+	strbuf = strcat(strbuf, str2); 
 	set_cursor_pos(0, 0);
-	for( int i = 0; i < 255; i++ )
+	println(strbuf, 0x0f);
-		println("X", i);
-	*/
 }

kernel/memory.c

@@ -0,0 +1 @@
+#include "memory.h"

kernel/memory.h

@@ -0,0 +1,2 @@
+char* malloc(unsigned int size);
+void mfree(char* p);

lib/str.c

@@ -0,0 +1,28 @@
+#include "str.h"
+
+unsigned int strlen(char* str) {
+	unsigned int len = 0;
+	for( char* c = str; *c != '\0'; c++ ) 	// search for end-of-string
+		len++;
+	
+	return len;
+}
+
+char* strcat(char* buf, char* str) {
+	unsigned int bufferlen = strlen(buf);
+
+	// remove the 0x0 char from the buffer
+	*(buf + bufferlen) = 0x3f;		// replace end-of-string 
+						// with a placeholder
+
+	// concat the str to buf
+	int cc = 0;
+	for( char* c = str; *c != '\0'; c++ ) {
+		*(buf + bufferlen + cc) = *c;
+		cc++;
+	}
+
+	*(buf + bufferlen + cc) = '\0'; 	// add end-of-string
+
+	return buf;
+}

lib/str.h

@@ -0,0 +1,2 @@
+unsigned int strlen(char* str);
+char* strcat(char* buf, char* str);

lib/strf.c

@@ -0,0 +1,15 @@
+#include "strf.h"
+
+#define int_offset 48
+// 0:48 - 9:57
+
+char* int_to_str(int i, char* strbuf) {
+	if( i == 0 ) {
+		return (char*)(int_offset);
+	} else {
+		char cbuf;
+		cbuf = (char)((i % 10) + int_offset);
+
+		return int_to_str(i / 10, strbuf + cbuf);
+	}
+}

lib/strf.h

@@ -0,0 +1 @@
+char* int_to_str(int i, char* strbuf);