GRUB Error 28 When Booting Kernel
Posted: Tue Jun 15, 2010 10:09 am
Hello. I'm working on a kernel and have encountered an issue. I switched from a 32-bit Ubuntu installation to a 64-bit Ubuntu installation recently. (To be honest, it wasn't that recently; I no longer have any 32-bit Ubuntu discs I'm willing to use.) I've started a kernel from scratch. I've attempted to compile my kernel but have received GRUB error 28 (selected item won't fit in memory). I've tried two different versions of GRUB; 0.5~ and an unknown version (whichever version is in JamesM's tutorials). After searching through my code for several hours, correcting every little thing, trying different ways to assemble, compile, and link the kernel, and comparing to other kernels, I could not find a solution. I used Google to look up information on GRUB error 28, then did the same to look for references to that error on this site. I've found no useful information (most of it involved "invalid configuration of the Linux kernel").
My tools:
- Ubuntu 10.04 LTS
- GCC version 4.4.3 (a 2009 build)
- GNU Binutils 2.20.1-system.20100303; GNU gold 1.9 (seems to replace LD or is a different version of it; objdump confirms everything it outputs is correct)
- GNU Make 3.81
- NASM 2.07 ("compiled on Nov 5 2009")
Here's how the kernel gets compiled:
Here's the (cut-down) assembly source; start.asm:
I don't think it's relevant, but here's the C code for the kernel. OBJDUMP confirms kmain to be there. Running -S with all optimization options shows it still there.
As you can see, this is just a skeleton of a project. There's very little to go wrong. I suspect it's my environment, but I'll leave the diagnosis to you guys. If anyone needs any additional information, I'll give it.
Thanks in advance for the time you take to read this, and especially any thought that goes into my issues.
Cheers,
-Aaron
My tools:
- Ubuntu 10.04 LTS
- GCC version 4.4.3 (a 2009 build)
- GNU Binutils 2.20.1-system.20100303; GNU gold 1.9 (seems to replace LD or is a different version of it; objdump confirms everything it outputs is correct)
- GNU Make 3.81
- NASM 2.07 ("compiled on Nov 5 2009")
Here's how the kernel gets compiled:
Code: Select all
nasm -felf32 -o obj/start.o src/arch/x86-32/start.asm
gcc -O2 -fexpensive-optimizations -fomit-frame-pointer -I./inc/ -Wall -pedantic -nostdinc -nostdlib -fno-builtin -fno-stack-protector -masm=intel -m32 -c -o obj/kmain.o src/kmain.c
ld -b elf32-i386 --oformat elf32-i386 -Tsrc/arch/x86-32/kernel.ld -o bin/kernel obj/start.o obj/kmain.o
Code: Select all
; 32-bit mode
bits 32
; Multiboot Flags
MBF_PAGE_ALIGN equ 0x01
MBF_MEMORY_INFO equ 0x02
; Multiboot Magic
MBB_HEADER equ 0x1BADB002
; Kernel Multiboot Fields
KMB_FLAGS equ (MBF_PAGE_ALIGN|MBF_MEMORY_INFO)
KMB_CHECKSUM equ -(MBB_HEADER+KMB_FLAGS)
; Globals and Externals here omitted, globals : start, multiboot; externals : code, bsss, end, kmain;
; Multiboot header
multiboot:
; Setup the multiboot header
dd MBB_HEADER
dd KMB_FLAGS
dd KMB_CHECKSUM
; Flags does not include A.OUT kludge; I've tried this with and without the kludge and the flag (and combinations of them)
; Start of the program (marked as the entry point in the linker script)
start:
; Code here is irrelevant. It first disables interrupts, sets up the stack, calls the kernel with the multiboot structure address passed, and finally halts processor execution
; NOTE: OBJDUMP confirms that the multiboot header is at the 1st megabyte of memory, exactly.
Code: Select all
void kmain(void *pMultiboot)
{
if (!pMultiboot)
return;
}
Thanks in advance for the time you take to read this, and especially any thought that goes into my issues.
Cheers,
-Aaron
