From 43fdee65b9d639b99cf442ab43796d32eb4ad3e9 Mon Sep 17 00:00:00 2001
From: lohrrrr <loh12345678909@outlook.com>
Date: Mon, 25 May 2026 14:43:58 +0300
Subject: [PATCH] =?UTF-8?q?=D0=A1=D0=B4=D0=B5=D0=BB=D0=B0=D0=BB=20=D0=B1?=
 =?UTF-8?q?=D0=B0=D0=B7=D0=BE=D0=B2=D0=BE=D0=B5=20=D1=8F=D0=B4=D1=80=D0=BE?=
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---
 kernel/kernel.c  | 67 ++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/linker.ld | 24 +++++++++++++++++
 kernel/start.s   | 26 +++++++++++++++++++
 3 files changed, 117 insertions(+)
 create mode 100644 kernel/kernel.c
 create mode 100644 kernel/linker.ld
 create mode 100644 kernel/start.s

diff --git a/kernel/kernel.c b/kernel/kernel.c
new file mode 100644
index 0000000..75af17c
--- /dev/null
+++ b/kernel/kernel.c
@@ -0,0 +1,67 @@
+// fether os kernel.
+#include <stddef.h>
+#include <stdint.h>
+
+// protecting compilation.
+#if defined(__linux__)
+	#error "You should compile all with a cross-compiler. See project wiki."
+#elif !defined(__i386__)
+	#error "This is an 32bit kernel. Please use i386 target."
+#endif
+
+volatile uint16_t* vga_buffer = (uint16_t*)0xB8000; // defining VGA text mode.
+
+// vga(2) settings
+const int VGA_COLS = 80;
+const int VGA_ROWS = 25;
+
+// terminal settings
+int term_col = 0;
+int term_row = 0;
+uint8_t term_color = 0x0F;
+
+// clearing the terminal
+void term_init() {
+	for(int col = 0; col < VGA_COLS; col++) {
+		for(int row = 0; row < VGA_ROWS; row++) {
+			const size_t index = (VGA_COLS * row) + col;
+			vga_buffer[index] = ((uint16_t)term_color << 8) | ' ';
+		}
+	}
+}
+
+void term_put(char c) {
+	switch(c) {
+		case '\n': // newline implemintation
+			{
+				term_col = 0;
+				term_row++;
+				break;
+			}
+		default: // if char doesn't match any special symbol
+			{
+				const size_t index = (VGA_COLS * term_row) + term_col;
+				vga_buffer[index] = ((uint16_t)term_color << 8) | c;
+				break;
+			}
+	}
+
+	if(term_col >= VGA_COLS) {
+		term_col = 0;
+		term_row++;
+	}
+
+
+	if(term_row >= VGA_ROWS) {
+		term_col = 0;
+		term_row = 0;
+	}
+}
+
+
+void term_print(const char* str) { for(size_t i = 0; str[i] != '\0'; i++) { term_put(str[i]); } }
+
+void kmain() {
+	term_init();
+	term_print("Kernel loaded.\nFether.");
+}
diff --git a/kernel/linker.ld b/kernel/linker.ld
new file mode 100644
index 0000000..4d6c890
--- /dev/null
+++ b/kernel/linker.ld
@@ -0,0 +1,24 @@
+{
+	. = 1M;
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.multiboot)
+	}
+	.text BLOCK(4K) : ALIGN(4K)
+	{
+		*(.text)
+	}
+	.rodata BLOCK(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+	.data BLOCK(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+	.bss BLOCK(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+	}
+}
diff --git a/kernel/start.s b/kernel/start.s
new file mode 100644
index 0000000..731a1bc
--- /dev/null
+++ b/kernel/start.s
@@ -0,0 +1,26 @@
+.extern kmain // entry
+.global start
+.set MB_MAGIC, 0x1BADB002
+.set MB_FLAGS, (1 << 0) | (1 << 1)
+.set MB_CHECKSUM, (0 - (MB_MAGIC + MB_FLAGS))
+
+.section .multiboot
+	.align 4
+	.long MB_MAGIC
+	.long MB_FLAGS
+	.long MB_CHECKSUM
+
+.section .bss
+	.align 16
+	stack_bottom:
+		.skip 4096
+	stack_top:
+
+.section .text
+	start:
+		mov $stack_top, %esp
+
+	hang:
+		cli
+		hlt
+		jmp hang