salam be hame dostan bebakhshid ke farsi neminevisam
man daram say mikonam barname nevisi sath paiin va kernel ro yad begiram hala be ye moshkel khoram harchi ke search kardam va maghale khondam chizi motevajeh nashodam
mamnon misham komakam konin
man 4 ta file neveshtam
boot.asm
;
Declare constants used for creating a multiboot header.
MBALIGN equ 1<<0 ; align loaded modules on page boundaries
MEMINFO equ 1<<1 ; provide memory map
FLAGS equ MBALIGN | MEMINFO ; this is the Multiboot 'flag' field
MAGIC equ 0x1BADB002 ; 'magic number' lets bootloader find the header
CHECKSUM equ -(MAGIC + FLAGS) ; checksum of above, to prove we are multiboot
; Declare a header as in the Multiboot Standard. We put this into a special
; section so we can force the header to be in the start of the final program.
; You don't need to understand all these details as it is just magic values that
; is documented in the multiboot standard. The bootloader will search for this
; magic sequence and recognize us as a multiboot kernel.
section .multiboot
align 4
dd MAGIC
dd FLAGS
dd CHECKSUM
; Currently the stack pointer register (esp) points at anything and using it may
; cause massive harm. Instead, we'll provide our own stack. We will allocate
; room for a small temporary stack by creating a symbol at the bottom of it,
; then allocating 16384 bytes for it, and finally creating a symbol at the top.
section .bootstrap_stack, nobits
align 4
stack_bottom:
resb 16384
stack_top:
; The linker script specifies _start as the entry point to the kernel and the
; bootloader will jump to this position once the kernel has been loaded. It
; doesn't make sense to return from this function as the bootloader is gone.
section .text
global _start
_start:
; Welcome to kernel mode! We now have sufficient code for the bootloader to
; load and run our operating system. It doesn't do anything interesting yet.
; Perhaps we would like to call printf("Hello, World\n"). You should now
; realize one of the profound truths about kernel mode: There is nothing
; there unless you provide it yourself. There is no printf function. There
; is no <stdio.h> header. If you want a function, you will have to code it
; yourself. And that is one of the best things about kernel development:
; you get to make the entire system yourself. You have absolute and complete
; power over the machine, there are no security restrictions, no safe
; guards, no debugging mechanisms, there is nothing but what you build.
; By now, you are perhaps tired of assembly language. You realize some
; things simply cannot be done in C, such as making the multiboot header in
; the right section and setting up the stack. However, you would like to
; write the operating system in a higher level language, such as C or C++.
; To that end, the next task is preparing the processor for execution of
; such code. C doesn't expect much at this point and we only need to set up
; a stack. Note that the processor is not fully initialized yet and stuff
; such as floating point instructions are not available yet.
; To set up a stack, we simply set the esp register to point to the top of
; our stack (as it grows downwards).
mov esp, stack_top
; We are now ready to actually execute C code. We cannot embed that in an
; assembly file, so we'll create a kernel.c file in a moment. In that file,
; we'll create a C entry point called kernel_main and call it here.
extern kernel_main
call kernel_main
; In case the function returns, we'll want to put the computer into an
; infinite loop. To do that, we use the clear interrupt ('cli') instruction
; to disable interrupts, the halt instruction ('hlt') to stop the CPU until
; the next interrupt arrives, and jumping to the halt instruction if it ever
; continues execution, just to be safe.
cli
.hang:
hlt
jmp .hang
kernel.c
#if !defined(__cplusplus)
#include <stdbool.h> /* C doesn't have booleans by default. */
#endif
#include <stddef.h>
#include <stdint.h>
/* Hardware text mode color constants. */
enum vga_color {
COLOR_BLACK = 0,
COLOR_BLUE = 1,
COLOR_GREEN = 2,
COLOR_CYAN = 3,
COLOR_RED = 4,
COLOR_MAGENTA = 5,
COLOR_BROWN = 6,
COLOR_LIGHT_GREY = 7,
COLOR_DARK_GREY = 8,
COLOR_LIGHT_BLUE = 9,
COLOR_LIGHT_GREEN = 10,
COLOR_LIGHT_CYAN = 11,
COLOR_LIGHT_RED = 12,
COLOR_LIGHT_MAGENTA = 13,
COLOR_LIGHT_BROWN = 14,
COLOR_WHITE = 15,
};
uint8_t make_color(enum vga_color fg, enum vga_color bg) {
return fg | bg << 4;
}
uint16_t make_vgaentry(char c, uint8_t color) {
uint16_t c16 = c;
uint16_t color16 = color;
return c16 | color16 << 8;
}
size_t strlen(const char* str) {
size_t ret = 0;
while ( str[ret] != 0 )
ret++;
return ret;
}
static const size_t VGA_WIDTH = 80;
static const size_t VGA_HEIGHT = 25;
size_t terminal_row;
size_t terminal_column;
uint8_t terminal_color;
uint16_t* terminal_buffer;
void terminal_initialize() {
terminal_row = 0;
terminal_column = 0;
terminal_color = make_color(COLOR_LIGHT_GREY, COLOR_BLACK);
terminal_buffer = (uint16_t*) 0xB8000;
for (size_t y = 0; y < VGA_HEIGHT; y++) {
for (size_t x = 0; x < VGA_WIDTH; x++) {
const size_t index = y * VGA_WIDTH + x;
terminal_buffer[index] = make_vgaentry(' ', terminal_color);
}
}
}
void terminal_setcolor(uint8_t color) {
terminal_color = color;
}
void terminal_putentryat(char c, uint8_t color, size_t x, size_t y) {
const size_t index = y * VGA_WIDTH + x;
terminal_buffer[index] = make_vgaentry(c, color);
}
void terminal_putchar(char c) {
terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
if (++terminal_column == VGA_WIDTH) {
terminal_column = 0;
if (++terminal_row == VGA_HEIGHT) {
terminal_row = 0;
}
}
}
void terminal_writestring(const char* data) {
size_t datalen = strlen(data);
for (size_t i = 0; i < datalen; i++)
terminal_putchar(data[i]);
}
#if defined(__cplusplus)
extern "C" /* Use C linkage for kernel_main. */
#endif
void kernel_main() {
/* Initialize terminal interface */
terminal_initialize();
/* Since there is no support for newlines in terminal_putchar
* yet, '\n' will produce some VGA specific character instead.
* This is normal.
*/
terminal_writestring("Hello, kernel World!\n");
}
linker.ld
/* The bootloader will look at this image and start execution at the symbol
designated as the entry point. */
ENTRY(_start)
/* Tell where the various sections of the object files will be put in the final
kernel image. */
SECTIONS
{
/* Begin putting sections at 1 MiB, a conventional place for kernels to be
loaded at by the bootloader. */
. = 1M;
/* First put the multiboot header, as it is required to be put very early
early in the image or the bootloader won't recognize the file format.
Next we'll put the .text section. */
.text BLOCK(4K) : ALIGN(4K)
{
*(.multiboot)
*(.text)
}
/* Read-only data. */
.rodata BLOCK(4K) : ALIGN(4K)
{
*(.rodata)
}
/* Read-write data (initialized) */
.data BLOCK(4K) : ALIGN(4K)
{
*(.data)
}
/* Read-write data (uninitialized) and stack */
.bss BLOCK(4K) : ALIGN(4K)
{
*(COMMON)
*(.bss)
*(.bootstrap_stack)
}
/* The compiler may produce other sections, by default it will put them in
a segment with the same name. Simply add stuff here as needed. */
}
grub.cfg
menuentry "myos" {
multiboot /boot/myos.bin
}
va dastorat zir ra estefade kardam
nasm -felf32 boot.asm -o boot.o
g++ -c kernel.cpp -o kernel.o -ffreestanding -fno-exceptions -fno-rtti
gcc boot.o kernel.o -T linker.ld -o myos.bin -nostdlib -nodefaultlibs -lgcc
mkdir -p isodir/boot/grub
cp myos.bin isodir/boot/myos.bin
cp grub.cfg isodir/boot/grub/grub.cfg
grub-mkrescue -o myos.iso isodir
qemu-system-i386 -cdrom myos.iso
vaghti gemu ejra mishe be error zir mikhoram
error: no multiboot header fund
kesy mitone komakam kone ke moshkel chi hast?
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