Grub Error 13 with pe format kernel

[neon]

Hello,

LD script has no equivalent on Visual Studio and it is much complicated

Not having an equivalent for linker scripts cleary is a disadvantage (I haven't checked if it's true for VS). For example, how are you going to ensure that the multiboot header will always be in the first 8k as your kernel grows?

There is not a linker script afaik but you can control function order. ie, you can insure your entry point is always the first function in the linker map. That which can contain the multiboot header, and using #pragma can align it properly as well.

Its what I am doing to support multiboot (although I dont use Grub) anyways.

[gedd]

The problem is the following : even if you align code and reorder function, the DOS header, file header, PE header ...etc are at the beginning of file, before the Magic number required to have a "recognized format"

[neon]

meh, 8k is plenty enough room. Resources and data are stored at the end of the PE file, so the headers altogether will remain the same when adding content to the file. All the headers combined are not that big.

[gedd]

Too big , or not too big ....
This is not the question, if GRUB found other data than a multiboot header at the begining of file it not recognise the format : error 13

[neon]

Hello,

Too big , or not too big ....
This is not the question, if GRUB found other data than a multiboot header at the begining of file it not recognise the format : error 13

Specification states that it must be within the first 8kb of the binary file. It is never at the beginning of the file. Knowing Grub follows the multiboot specification, it should find the structure fine if its within the first 8kb without error.

[Firestryke31]

Another idea might be to rewrite the DOS part of the EXE with a return (or whatever the equivalent is), some padding, then the multiboot structure. Seeing as the DOS part is ignored in everything but, well, DOS, it shouldn't cause too many problems to simply exit.

[gedd]

Specification states that it must be within the first 8kb of the binary file. It is never at the beginning of the file. Knowing Grub follows the multiboot specification, it should find the structure fine if its within the first 8kb without error.

Oups, shame on me !
I will make some tests in this way

[gedd]

I made some test and verification

My pe kernel is arround 2,5 k so my multiboot header is in the 8k limit
No change i still have an error 13

I try to place multiboot in the dos stub, no way , error 13 again

Does anyone has ever made a PE kernel with grub ?

[fronty]

Is the header correctly aligned? Spec says it has to be 32-bit aligned.

[gedd]

Yes MAGIC number is @0x400

[gedd]

Well i resume :

To be GRUB/multiboot compliant a kernel not in the elf format must :

- have multiboot header placed in the first 8k
- be 32 aligned
- have AOUT Kludge info following standard multiboot header info

My PE kernel is compliant with all of this requirement.

Anything else required ?

[Combuster]

- have correct multiboot header placed in the first 8k
- be 32 aligned
- have valid AOUT Kludge info following standard multiboot header info

Fixed that for you.

Oh and, don't try to load under 1M

[gedd]

Having a correct multiboot was implicit.

so , is this multiboot is correct ?

Code: Select all

multiboot_header:
                dd(0x1BADB002)                ; magic
                dd(1 << 16)|(1<<0)|(1<<1)     ; flags
                dd(-(0x1BADB002 + ((1 << 16)|(1<<0)|(1<<1)))) ; checksum
                dd(0x00101000)                ; header_addr
                dd(0x00101000)                ; load_addr
                dd(0x00102000)                ; load_end_addr
                dd(0x00102000)                ; bss_end_addr
                dd(0x00101030)                ; entry_addr
                dd(0x00000000)                ; mode_type
                dd(0x00000000)                ; width
                dd(0x00000000)                ; height
                dd(0x00000000)                ; depth
            

Oh and, don't try to load under 1M

Grub loading himself the specified kernel, i assume it does it at 1M no ?

[gedd]

Someone here have ever made a PE file kernel loaded by Grub ?

[Solar]

What does mbchk say about your kernel binary?

Apart from that, I found no references that it would indeed be possible to load a PE kernel using GRUB. It mentions ELF and the various a.out formats all over the place, but every article I googled combining GRUB and "PE format" recommends going the cross-compiler / ELF format way.

That doesn't mean it can't be done, it just means you're in pretty much uncharted territory.

Which is why we made it dead simple to build the crosscompiler environment. Using Cygwin is not exactly rocket science, and the points Creature made are very valid: If you encounter problems further down the road, one half the people here couldn't reproduce your problems even if they wanted to, because they're on Linux.