OSDev.org

Posted: **Thu Oct 29, 2009 11:30 pm**

I have an (*.iso) file that contains GRUB and my kernel binary file. I have one option in my menu.lst file:

kernel       /boot/main/kernel.bin

If I try mounting the ISO in an emulator, I receive "Error 13" from GRUB.

mbchk kernel.bin returns:

Code: Select all

kernel.bin: No Multiboot header.

Here's the output if I add -M after linking all of the files:
http://pastebin.com/m470c3d41

Code: Select all

Allocating common symbols
Common symbol       size              file

textmemptr          0x4               screen_display.o

Memory Configuration

Name             Origin             Length             Attributes
*default*        0x0000000000000000 0xffffffffffffffff

Linker script and memory map

                0x0000000000100000                phys = 0x100000

.rodata.str1.1  0x0000000000000000       0x13
 .rodata.str1.1
                0x0000000000000000       0x13 main.o

.text           0x0000000000100000     0x1000
                0x0000000000100000                code = .
 *(.text)
 .text          0x0000000000100000       0x38 start.o
                0x0000000000100000                start
                0x000000000010000c                mboot
 .text          0x0000000000100038       0xb4 main.o
                0x0000000000100038                memcpy
                0x0000000000100060                memset
                0x0000000000100083                memsetw
                0x00000000001000a4                strlen
                0x00000000001000bd                readPortData
                0x00000000001000c4                sendPortData
                0x00000000001000d0                main
 *fill*         0x00000000001000ec        0x4 00
 .text          0x00000000001000f0      0x26b screen_display.o
                0x00000000001000f0                settextcolor
                0x0000000000100108                move_csr
                0x0000000000100170                cls
                0x00000000001001d2                init_video
                0x00000000001001e8                scroll
                0x000000000010026b                drawChar
                0x000000000010032a                drawText
 *(.rodata)
                0x0000000000101000                . = ALIGN (0x1000)
 *fill*         0x000000000010035b      0xca5 00

.data           0x0000000000101000     0x1000
                0x0000000000101000                data = .
 *(.data)
 .data          0x0000000000101000        0x0 start.o
 .data          0x0000000000101000        0x0 main.o
 .data          0x0000000000101000        0x4 screen_display.o
                0x0000000000101000                attrib
                0x0000000000102000                . = ALIGN (0x1000)
 *fill*         0x0000000000101004      0xffc 00

.bss            0x0000000000102000     0x3004
                0x0000000000102000                bss = .
 *(.bss)
 .bss           0x0000000000102000     0x2000 start.o
 .bss           0x0000000000104000        0x0 main.o
 .bss           0x0000000000104000        0x8 screen_display.o
                0x0000000000104000                csr_x
                0x0000000000104004                csr_y
                0x0000000000105000                . = ALIGN (0x1000)
 *fill*         0x0000000000104008      0xff8 00
 COMMON         0x0000000000105000        0x4 screen_display.o
                0x0000000000105000                textmemptr
                0x0000000000105004                end = .
LOAD start.o
LOAD main.o
LOAD screen_display.o
OUTPUT(kernel.bin binary)

.comment        0x0000000000000000       0x48
 .comment       0x0000000000000000       0x24 main.o
 .comment       0x0000000000000024       0x24 screen_display.o

.note.GNU-stack
                0x0000000000000000        0x0
 .note.GNU-stack
                0x0000000000000000        0x0 main.o
 .note.GNU-stack
                0x0000000000000000        0x0 screen_display.o

Does the output file that defines multibooting need to be read within the first 8 KBs of the kernel binary?

Here is my build.sh file:

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nasm -f aout -o start.o start.asm

gcc -Wall -O -fstrength-reduce -fomit-frame-pointer -finline-functions -nostdinc -fno-builtin -I./include -c -o main.o main.c
gcc -Wall -O -fstrength-reduce -fomit-frame-pointer -finline-functions -nostdinc -fno-builtin -I./include -c -o screen_display.o screen_display.c

ld -T link.ld -o kernel.bin start.o main.o screen_display.o
wait

Multiboot definition:

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ALIGN 4

global mboot

mboot:
	MULTIBOOT_PAGE_ALIGN		equ 1<<0
	MULTIBOOT_MEMORY_INFO		equ 1<<1
	MULTIBOOT_AOUT_KLUDGE		equ 1<<16
	MULTIBOOT_HEADER_MAGIC		equ 0x1BADB002
	MULTIBOOT_HEADER_FLAGS		equ MULTIBOOT_PAGE_ALIGN | MULTIBOOT_MEMORY_INFO | MULTIBOOT_AOUT_KLUDGE
	MULTIBOOT_CHECKSUM			equ -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
	EXTERN code, bss, end
	
	dd MULTIBOOT_HEADER_MAGIC
	dd MULTIBOOT_HEADER_FLAGS
	dd MULTIBOOT_CHECKSUM
	
	dd mboot
	dd code
	dd bss
	dd end
	dd start

Hopefully the above is legible, and logical of what I'm attempting to do. Is it possible to rearrange my build.sh file to ensure that the multiboot definition is loaded within the first 8 KBs of the binary? Or, if that's not the issue, what could be the issue in the huge mess above?

Thanks!

Posted: **Fri Oct 30, 2009 12:03 am**

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GRUB and Multiboot Kernel?

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