Added:

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

*NOTE*: iceOS not works at this stage.

Makefile

@@ -0,0 +1,10 @@
+iso:
+	grub-mkrescue iso_root -o iceOS.iso
+
+run:
+	qemu-system-x86_64 -cdrom iceOS.iso
+
+clean:
+	rm -rf obj/ kernel/*.o kernel/cpu/*.o iso_root/boot/kernel.elf
+	rm -rf kernel/drivers/*.o kernel/libc/*.o
+	rm -rf PyramidKernel.iso bochslog.txt commands

build.sh

@@ -0,0 +1,30 @@
+# grub config file
+mkdir -p iso_root/boot/grub/
+cat iso_root/boot/grub/grub.cfg <<EOF
+set timeout = 0
+set default = 0
+
+menuentry "iceOS" {
+    multiboot2 /boot/kernel.elf
+    boot
+}
+EOF
+
+# CPU
+mkdir -p obj/
+make -C kernel/cpu
+cp kernel/cpu*.o obj/
+
+# Kernel
+make -C kernel/
+cp kernel/*.o obj/
+
+# Drivers
+make -C kernel/drivers/
+cp kernel/drivers/*.o obj/
+
+# Libc
+make -C kernel/libc
+cp kernel/libc/*.o obj/
+
+i686-elf-ld -melf_i386 -nostdlib -O2 -T link.ld -o iso_root/boot/kernel.elf obj/*.o

kernel/Makefile

@@ -0,0 +1,10 @@
+OBJS = kernel_main.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/cpu/kernel_load.asm

@@ -6,14 +6,14 @@
 ;   https://github.com/ice-bit/iceOS  ;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-global kernel_loader
+global kernel_load
-extern main
+extern kernel_main
 
 section .text
 kernel_loader:
     mov esp, kernel_stack + KERNEL_STACK_SZ ; Stack pointer
     push ebx
-    call main ; jump to kernel's main function
+    call kernel_main ; jump to kernel's main function
 .loop:
     jmp .loop ; endless loop
 

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

kernel/kernel_main.c

@@ -0,0 +1,9 @@
+#include "drivers/tty.h"
+#include "libc/stdio.h"
+
+void kernel_main() {
+    clear_prompt();
+    init_prompt();
+
+    puts("Hello World!");
+}

kernel/libc/Makefile

@@ -0,0 +1,10 @@
+OBJS = stdio.o string.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/libc/stdio.c

@@ -1,7 +1,6 @@
 #include "stdio.h"
 #include "string.h"
-#include "drivers/shell.h"
+#include "../drivers/tty.h"
-
 
 int printf(const char *format, ...) {
     char buf[20],c,*s;
@@ -20,32 +19,36 @@ int printf(const char *format, ...) {
                 case 'i':
                     val = va_arg(ap, int);
                     itoa(val, buf, 10);
-                    printk(buf);
+                    kprint(buf);
                     break;
                 case 'x':
                     uval = va_arg(ap, uint32_t);
                     uitoa(uval, buf, 16);
-                    printk(buf);
+                    kprint(buf);
                     break;
                 case 'd':
                     uval = va_arg(ap, uint32_t);
                     uitoa(uval, buf, 10);
-                    printk(buf);
+                    kprint(buf);
                     break;
                 case 'c':
                     s = va_arg(ap, char*);
-                    printk_c(&c, 1);
+                    kprint_c(&c, 1, WHITE, BLACK);
                     break;
                 case 's':
                     s = va_arg(ap, char*);
-                    printk(s);
+                    kprint(s);
                     break;
                 default:
-                    printk_c((char*)format+1, 1);
+                    kprint_c((char*)format+1, 1, WHITE, BLACK);
             }
         } else
-            printk_c((char*)format+1, 1);
+            kprint_c((char*)format+1, 1, WHITE, BLACK);
     }
     va_end(ap);
     return 0;
 }
+
+void puts(int8_t *buf) {
+    printf("%s\n", buf);
+}

kernel/libc/stdio.h

@@ -1,10 +1,19 @@
+/**************************************
+ *          iceOS Kernel              *
+ * Developed by Marco 'icebit' Cetica * 
+ *            (c) 2019                *
+ *       Released under GPLv3         *
+ * https://github.com/ice-bit/iceOS   *
+ ***************************************/
+
 #ifndef _STDIO_H_
-#define _STDIO_H
+#define _STDIO_H_
 
 #include <stdint.h>
 #include <stddef.h>
 #include <stdarg.h>
 
 int printf(const char *format, ...);
+void puts(uint8_t *buf);
 
 #endif

link.ld

@@ -0,0 +1,35 @@
+ENTRY(kernel_load)
+
+. = 0x00100000;
+
+SECTIONS {
+
+    .boot ALIGN (0x1000):
+    {
+        *(.multiboot)
+    }
+
+    .text ALIGN (0x1000):
+    {
+        *(.text)
+    }
+
+    .rodata ALIGN (0x1000):
+    {
+        *(.rodata*)
+    }
+
+    .data ALIGN (0x1000):
+    {
+        *(.data)
+    }
+
+    .bss ALIGN (0x1000):
+    {
+        *(COMMON)
+        *(.bss)
+    }
+
+}
+
+end = .;