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kernel /kernel

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/* Link.ld -- Linker script for the kernel - ensure everything goes in the */

/*            Correct place.  */

/*            Original file taken from Bran's Kernel Development */

/*            tutorials: http://www.osdever.net/bkerndev/index.php. */



ENTRY(start)

SECTIONS

{



    .text 0x100000 :

    {

        code = .; _code = .; __code = .;

        *(.text)

        . = ALIGN(4096);

    }



    .data :

    {

        data = .; _data = .; __data = .;

        *(.data)

        *(.rodata)

        . = ALIGN(4096);

    }



    .bss :

    {

        bss = .; _bss = .; __bss = .;

        *(.bss)

        . = ALIGN(4096);

    }



    end = .; _end = .; __end = .;

}

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;

; boot.s -- Kernel start location. Also defines multiboot header.

;           Based on Bran's kernel development tutorial file start.asm

;



MBOOT_PAGE_ALIGN    equ 1<<0    ; Load kernel and modules on a page boundary

MBOOT_MEM_INFO      equ 1<<1    ; Provide your kernel with memory info

MBOOT_HEADER_MAGIC  equ 0x1BADB002 ; Multiboot Magic value

; NOTE: We do not use MBOOT_AOUT_KLUDGE. It means that GRUB does not

; pass us a symbol table.

MBOOT_HEADER_FLAGS  equ MBOOT_PAGE_ALIGN | MBOOT_MEM_INFO

MBOOT_CHECKSUM      equ -(MBOOT_HEADER_MAGIC + MBOOT_HEADER_FLAGS)





[BITS 32]                       ; All instructions should be 32-bit.



[GLOBAL mboot]                  ; Make 'mboot' accessible from C.

[EXTERN code]                   ; Start of the '.text' section.

[EXTERN bss]                    ; Start of the .bss section.

[EXTERN end]                    ; End of the last loadable section.



mboot:

    dd  MBOOT_HEADER_MAGIC      ; GRUB will search for this value on each

                                ; 4-byte boundary in your kernel file

    dd  MBOOT_HEADER_FLAGS      ; How GRUB should load your file / settings

    dd  MBOOT_CHECKSUM          ; To ensure that the above values are correct

    

    dd  mboot                   ; Location of this descriptor

    dd  code                    ; Start of kernel '.text' (code) section.

    dd  bss                     ; End of kernel '.data' section.

    dd  end                     ; End of kernel.

    dd  start                   ; Kernel entry point (initial EIP).



[GLOBAL start]                  ; Kernel entry point.

[EXTERN main]                   ; This is the entry point of our C code



start:

    ; Load multiboot information:

    push    eax

    push    ebx



    ; Execute the kernel:

    cli                         ; Disable interrupts.

    call main                   ; call our main() function.

    jmp $                       ; Enter an infinite loop, to stop the processor

                                ; executing whatever rubbish is in the memory

                                ; after our kernel!

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# Makefile for JamesM's kernel tutorials.

# The C and C++ rules are already setup by default.

# The only one that needs changing is the assembler 

# rule, as we use nasm instead of GNU as.



SOURCES=boot.o main.o common.o monitor.o



CFLAGS=-nostdlib -nostdinc -fno-builtin -fno-stack-protector

LDFLAGS=-Tlink.ld

ASFLAGS=-felf



all: $(SOURCES) link



clean:

	-rm *.o kernel



link:

	ld $(LDFLAGS) -o kernel $(SOURCES)



.s.o:

	nasm $(ASFLAGS) $<

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timeout 1



title	JamesM's Tutorial

	root (fd0)

	kernel /kernel