move stuff aroundd

src/kernel/entry.asm

@@ -0,0 +1,5 @@
+section .text
+    [bits 32]
+    [extern init]
+    call init
+    jmp $

src/kernel/kernel.c

@@ -0,0 +1,7 @@
+#include "print.h"
+
+void init(void)
+{
+    print_init();
+    println("Starting nub-os");
+}

src/kernel/makefile

@@ -0,0 +1,19 @@
+CC = i386-elf-gcc -ffreestanding -m32
+
+kernel.bin: entry.o kernel.o mem.o print.o
+	i386-elf-ld -o kernel.bin -Ttext 0x1000 entry.o kernel.o mem.o print.o --oformat binary
+
+entry.o: entry.asm
+	nasm -f elf -o entry.o entry.asm
+
+kernel.o: kernel.c
+	$(CC) -c -o kernel.o kernel.c
+
+mem.o: mem.c
+	$(CC) -c -o mem.o mem.c
+
+print.o: print.c
+	$(CC) -c -o print.o print.c
+
+clean:
+	@rm *.o *.bin 2>/dev/null || true

src/kernel/mem.c

@@ -0,0 +1,26 @@
+#include "mem.h"
+
+void* memcpy(void* dest, const void* src, long n)
+{
+    char* d = dest;
+    const char* s = src;
+    for (long i = 0; i < n; i++)
+        d[i] = s[i];
+    return dest;
+}
+
+void* memset(void* dest, int val, long n)
+{
+    char* d = dest;
+    for (long i = 0; i < n; i++)
+        d[i] = val;
+    return dest;
+}
+
+long strlen(const char* str)
+{
+    long len = 0;
+    while (str[len])
+        len++;
+    return len;
+}

src/kernel/mem.h

@@ -0,0 +1,3 @@
+void* memcpy(void* dest, const void* src, long n);
+void* memset(void* dest, int val, long n);
+long strlen(const char* str);

src/kernel/print.c

@@ -0,0 +1,41 @@
+#include "print.h"
+
+#define VGA_WIDTH 80
+#define VGA_HEIGHT 25
+
+char* vga_text_pos;
+
+void print_init(void)
+{
+    vga_text_pos = (char*)0xb8000;
+}
+
+void print_newline(void)
+{
+    vga_text_pos += 160 - ((vga_text_pos - (char*)0xb8000) % 160);
+}
+
+void print_clr(const char* string, enum VGA_FG_COLOR fg_color, enum VGA_BG_COLOR bg_color)
+{
+    for (int i = 0; string[i]; i++)
+    {
+        *vga_text_pos++ = string[i];
+        *vga_text_pos++ = (bg_color << 4) | fg_color;
+    }
+}
+
+void println_clr(const char* string, enum VGA_FG_COLOR fg_color, enum VGA_BG_COLOR bg_color)
+{
+    print_clr(string, fg_color, bg_color);
+    print_newline();
+}
+
+void print(const char* string)
+{
+    print_clr(string, VGA_FG_WHITE, VGA_BG_BLACK);
+}
+
+void println(const char* string)
+{
+    println_clr(string, VGA_FG_WHITE, VGA_BG_BLACK);
+}

src/kernel/print.h

@@ -0,0 +1,41 @@
+enum VGA_FG_COLOR
+{
+    VGA_FG_BLACK = 0x0,
+    VGA_FG_BLUE = 0x1,
+    VGA_FG_GREEN = 0x2,
+    VGA_FG_CYAN = 0x3,
+    VGA_FG_RED = 0x4,
+    VGA_FG_MAGENTA = 0x5,
+    VGA_FG_BROWN = 0x6,
+    VGA_FG_LIGHT_GRAY = 0x7,
+    VGA_FG_DARK_GRAY = 0x8,
+    VGA_FG_LIGHT_BLUE = 0x9,
+    VGA_FG_LIGHT_GREEN = 0xA,
+    VGA_FG_LIGHT_CYAN = 0xB,
+    VGA_FG_LIGHT_RED = 0xC,
+    VGA_FG_LIGHT_MAGENTA = 0xD,
+    VGA_FG_YELLOW = 0xE,
+    VGA_FG_WHITE = 0xF,
+};
+
+enum VGA_BG_COLOR
+{
+    VGA_BG_BLACK = 0x0,
+    VGA_BG_BLUE = 0x1,
+    VGA_BG_GREEN = 0x2,
+    VGA_BG_CYAN = 0x3,
+    VGA_BG_RED = 0x4,
+    VGA_BG_MAGENTA = 0x5,
+    VGA_BG_BROWN = 0x6,
+    VGA_BG_LIGHT_GRAY = 0x7,
+};
+
+void print_init(void);
+
+void print_newline(void);
+
+void print(const char* string);
+void println(const char* string);
+
+void print_clr(const char* string, enum VGA_FG_COLOR fg_color, enum VGA_BG_COLOR bg_color);
+void println_clr(const char* string, enum VGA_FG_COLOR fg_color, enum VGA_BG_COLOR bg_color);