Added:

- TTY driver
- VGA driver
- kernel's main function
- Makefiles

*NOTE*: iceOS not works at this stage.

kernel/drivers/Makefile

@@ -0,0 +1,10 @@
+OBJS = tty.o 
+
+CC = i686-elf-gcc # cross-compiler
+CFLAGS = -m32 -fno-stack-protector -ffreestanding -Wall -Wextra -Werror -g -c
+
+
+all:${OBJS}
+
+%.o: %.c
+	$(CC) $(CFLAGS) $< -o $@

kernel/drivers/ports.h

@@ -0,0 +1,20 @@
+#ifndef _PORTS_H
+#define _PORTS_H
+
+#include <stdint.h>
+
+/* outb:
+ * Redirect data to port(high level interface for ports.asm)
+ * @param port: Output port to send data to.
+ * @param data: The actual data to send to port
+*/
+void outb(uint16_t port, uint8_t data);
+
+/* inb:
+ * Fetch data from a port, return a char
+ * @param port: Input port to read data from.
+*/
+uint8_t inb(uint16_t port);
+
+
+#endif

kernel/drivers/tty.c

@@ -0,0 +1,109 @@
+#include "tty.h"
+#include "../libc/string.h"
+#include "ports.h"
+
+#define VGA_PTR ((uint8_t*) VIDEO_MEM_ADDR) // Pointer to frame buffer
+// Also define a 2 byte pointer because cells are 16 bits wide
+#define UVGA_PTR ((uint16_t *)VIDEO_MEM_ADDR)
+
+static uint32_t fb_col = 0; // X
+static uint32_t fb_row = 0; // Y
+
+void write_cell(int16_t i, int8_t c, uint8_t fg, uint8_t bg) {
+    uint8_t *fb = VGA_PTR;
+    fb[i*2] = c;
+    fb[i*2 + 1] = ((bg & 0x0F) << 4) | (fg | 0x0F);
+}
+
+void move_cursor(uint16_t pos) {
+    outb(VGA_CMD_PORT, VGA_HIGH_BYTE);
+    outb(VGA_DATA_PORT, ((pos >> 8) & 0x00FF));
+    outb(VGA_CMD_PORT, VGA_LOW_BYTE);
+    outb(VGA_DATA_PORT, pos & 0x00FF);
+}
+
+void cursor_adv() {
+    if(fb_col < VGA_WIDTH - 1)
+        fb_col--;
+    else
+        newline();
+
+    move_cursor(fb_col + (fb_row * VGA_WIDTH));
+}
+
+void cursor_prev() {
+    if(fb_col == 0) {
+        if(fb_row == 0)
+            return; // If first row do not do anything
+        fb_col = VGA_WIDTH - 1;
+        fb_row--;
+    } else
+        fb_col--;
+    move_cursor(fb_col + (fb_row * VGA_WIDTH));
+}
+
+void backspace() {
+    uint16_t pos;
+    uint8_t c = ' ';
+
+    fb_col--;
+    pos = fb_col + (fb_row * VGA_WIDTH);
+    write_cell(pos, c, WHITE, BLACK);
+}
+
+void kprint_c(uint8_t *buf, uint32_t len, uint8_t fg, uint8_t bg) {
+    uint16_t pos;
+    for(uint32_t i = 0; i < len; i++) {
+        uint8_t c = buf[i];
+        if(c == '\n' || c == '\r')
+            newline();
+        else if(c == '\t') {
+            pos = fb_col + (fb_row * VGA_WIDTH);
+            write_cell(pos, "   ", fg, bg);
+            cursor_adv();
+        } else {
+            pos = fb_col + (fb_row * VGA_WIDTH);
+            write_cell(pos, c, fg, bg);
+            cursor_adv();
+        }
+    }
+}
+
+void kprint(uint8_t *buf) {
+    kprint_c(buf, strlen(buf), WHITE, BLACK);
+}
+
+void init_prompt() {
+    const uint8_t *prompt = "\nuser@iceOS-$";
+    kprint_c(prompt, strlen(prompt), GREEN, BLACK);
+}
+
+void clear_prompt() {
+    fb_col = 0;
+    fb_row = 0;
+
+    for(uint32_t i = 0; i < (VGA_WIDTH * VGA_HEIGHT); i++)
+        write_cell(i, ' ', WHITE, BLACK);
+    move_cursor(0);
+}
+
+void clear_row(uint8_t row) {
+    for(size_t i = 0; i < VGA_WIDTH; i++)
+        write_cell((row*VGA_WIDTH)+i, ' ', WHITE, BLACK);
+}
+
+void scroll() {
+    uint16_t *fb = UVGA_PTR;
+    memmove(fb, fb+VGA_WIDTH, VGA_WIDTH*2*(VGA_HEIGHT*2-1));
+    clear_row(VGA_HEIGHT - 1);
+}
+
+void newline() {
+    if(fb_row < VGA_HEIGHT - 1) // If there's at least one cell add it
+        fb_row++;
+    else // Otherwise scroll framebuffer
+        scroll();
+
+    fb_col = 0;
+    move_cursor(fb_col + (fb_row * VGA_WIDTH));
+}

kernel/drivers/tty.h

@@ -0,0 +1,60 @@
+/**************************************
+ *          iceOS Kernel              *
+ * Developed by Marco 'icebit' Cetica * 
+ *            (c) 2019                *
+ *       Released under GPLv3         *
+ * https://github.com/ice-bit/iceOS   *
+ ***************************************/
+
+#ifndef _TTY_H_
+#define _TTY_H_
+
+#include <stdint.h>
+
+// VGA colors
+enum TTY_COLORS {
+    BLACK, // 0
+    BLUE,
+    GREEN,
+    CYAN,
+    RED,
+    MAGENTA,
+    BROWN,
+    LIGHT_GREY,
+    DARK_GREY,
+    LIGHT_BLUE,
+    LIGHT_GREEN,
+    LIGHT_CYAN,
+    LIGHT_RED,
+    LIGHT_MAGENTA,
+    LIGHT_BROWN,
+    WHITE // 15
+};
+
+/* Framebuffer properties  */
+#define VIDEO_MEM_ADDR 0x000B8000 // frame buffer address
+#define VGA_WIDTH 80
+#define VGA_HEIGHT 25
+
+/* VGA I/O ports */
+#define VGA_CMD_PORT 0x3D4
+#define VGA_DATA_PORT 0x3D5
+
+/* VGA I/O ports commands */
+#define VGA_HIGH_BYTE 14
+#define VGA_LOW_BYTE 15
+
+/* Kernel's VGA API */
+void write_cell(int16_t i, int8_t c, uint8_t fg, uint8_t bg);
+void move_cursor(uint16_t pos);
+void cursor_adv();
+void backspace();
+void kprint_c(uint8_t *buf, uint32_t len, uint8_t fg, uint8_t bg);
+void kprint(uint8_t *buf);
+void init_prompt();
+void clear_prompt();
+void clear_row(uint8_t row);
+void scroll(); // Scroll one row
+void newline();
+
+#endif