From d069fc23bdeba69a2f0c83d53fa9d32530430c3b Mon Sep 17 00:00:00 2001
From: Hjin-BF <kirillroblox71@gmail.com>
Date: Fri, 27 Feb 2026 22:22:48 +0200
Subject: [PATCH] Initial bootloader and kernel loader

---
 .gitignore                     |  4 +++
 Makefile                       | 23 +++++++++++++++
 linker.ld                      | 27 +++++++++++++++++
 sys/arch/x86_64/boot.s         | 17 +++++++++++
 sys/arch/x86_64/bootloader.asm | 54 ++++++++++++++++++++++++++++++++++
 sys/arch/x86_64/kernel.asm     | 19 ++++++++++++
 sys/kern/main.c                | 16 ++++++++++
 7 files changed, 160 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 linker.ld
 create mode 100644 sys/arch/x86_64/boot.s
 create mode 100644 sys/arch/x86_64/bootloader.asm
 create mode 100644 sys/arch/x86_64/kernel.asm
 create mode 100644 sys/kern/main.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..962f7aa
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+build/
+*.o
+*.bin
+*.iso
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..0fd4164
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,23 @@
+CC = x86_64-elf-gcc
+LD = x86_64-elf-ld
+
+CFLAGS = -ffreestanding -O2 -Wall -Wextra
+LDFLAGS = -T linker.ld -nostdlib
+
+OBJS = \
+    sys/arch/x86_64/boot.o \
+    sys/kern/main.o
+
+all: kernel.bin
+
+kernel.bin: $(OBJS)
+	$(LD) $(LDFLAGS) -o kernel.bin $(OBJS)
+
+sys/arch/x86_64/boot.o:
+	$(CC) $(CFLAGS) -c sys/arch/x86_64/boot.s -o sys/arch/x86_64/boot.o
+
+sys/kern/main.o:
+	$(CC) $(CFLAGS) -c sys/kern/main.c -o sys/kern/main.o
+
+clean:
+	rm -f $(OBJS) kernel.bin
diff --git a/linker.ld b/linker.ld
new file mode 100644
index 0000000..b54c328
--- /dev/null
+++ b/linker.ld
@@ -0,0 +1,27 @@
+ENTRY(_start)
+
+SECTIONS
+{
+    . = 1M;
+
+    .text :
+    {
+        *(.multiboot)
+        *(.text*)
+    }
+
+    .rodata :
+    {
+        *(.rodata*)
+    }
+
+    .data :
+    {
+        *(.data*)
+    }
+
+    .bss :
+    {
+        *(.bss*)
+    }
+}
diff --git a/sys/arch/x86_64/boot.s b/sys/arch/x86_64/boot.s
new file mode 100644
index 0000000..4cf8b2e
--- /dev/null
+++ b/sys/arch/x86_64/boot.s
@@ -0,0 +1,17 @@
+.section .multiboot
+.align 4
+.long 0x1BADB002
+.long 0x0
+.long -(0x1BADB002)
+
+.section .text
+.global _start
+.type _start, @function
+
+_start:
+    cli
+    call kernel_main
+
+.hang:
+    hlt
+    jmp .hang
diff --git a/sys/arch/x86_64/bootloader.asm b/sys/arch/x86_64/bootloader.asm
new file mode 100644
index 0000000..974b6d7
--- /dev/null
+++ b/sys/arch/x86_64/bootloader.asm
@@ -0,0 +1,54 @@
+[org 0x7C00]
+bits 16
+
+KERNEL_OFFSET equ 0x1000
+
+start:
+    cli
+    mov [BOOT_DRIVE], dl
+
+    xor ax, ax
+    mov ds, ax
+    mov es, ax
+    mov ss, ax
+    mov sp, 0x7C00
+    sti
+
+    call load_kernel
+
+    jmp KERNEL_OFFSET
+
+; -----------------------
+; Зчитування kernel
+; -----------------------
+
+load_kernel:
+    mov bx, KERNEL_OFFSET   ; куди завантажити
+    mov dh, 5               ; кількість секторів (тимчасово 5)
+
+    mov dl, [BOOT_DRIVE]
+    mov ah, 0x02            ; BIOS read sector
+    mov al, dh              ; скільки секторів
+    mov ch, 0x00            ; cylinder
+    mov dh, 0x00            ; head
+    mov cl, 0x02            ; сектор 2 (після bootloader)
+    int 0x13
+
+    jc disk_error
+    ret
+
+disk_error:
+    mov si, error_msg
+.print:
+    lodsb
+    cmp al, 0
+    je $
+    mov ah, 0x0E
+    int 0x10
+    jmp .print
+
+BOOT_DRIVE db 0
+error_msg db "Disk read error!", 0
+
+times 510 - ($ - $$) db 0
+dw 0xAA55
diff --git a/sys/arch/x86_64/kernel.asm b/sys/arch/x86_64/kernel.asm
new file mode 100644
index 0000000..6c94ca4
--- /dev/null
+++ b/sys/arch/x86_64/kernel.asm
@@ -0,0 +1,19 @@
+[org 0x1000]
+bits 16
+
+start:
+    mov si, message
+
+.print:
+    lodsb
+    cmp al, 0
+    je .hang
+    mov ah, 0x0E
+    int 0x10
+    jmp .print
+
+.hang:
+    hlt
+    jmp .hang
+
+message db "Kernel loaded successfully!", 0
diff --git a/sys/kern/main.c b/sys/kern/main.c
new file mode 100644
index 0000000..2f0f747
--- /dev/null
+++ b/sys/kern/main.c
@@ -0,0 +1,16 @@
+#include <stddef.h>
+
+void kernel_main(void) {
+    volatile char *video = (volatile char*) 0xB8000;
+
+    const char *msg = "LiteOS kernel started";
+
+    for (size_t i = 0; msg[i] != '\0'; i++) {
+        video[i * 2] = msg[i];
+        video[i * 2 + 1] = 0x07; // світло-сірий текст
+    }
+
+    while (1) {
+        __asm__("hlt");
+    }
+}