Weevil (planned)

iansjack · **Posted:** Fri Feb 06, 2015 6:53 am

omarrx024 wrote:

iansjack wrote:

Rather than all the kludging with 16-bit and/or Virtual 8086 mode, why not just write a proper disk driver?

Because he wants a DOS-like OS, which probably means it would be 16-bit.

In that case talk of switching between 32-bit and 16-bit, and Virtual 8086 mode, is irrelevant isn't it?

BrightLight · **Posted:** Fri Feb 06, 2015 7:13 am

iansjack wrote:

omarrx024 wrote:

iansjack wrote:

Rather than all the kludging with 16-bit and/or Virtual 8086 mode, why not just write a proper disk driver?

Because he wants a DOS-like OS, which probably means it would be 16-bit.

In that case talk of switching between 32-bit and 16-bit, and Virtual 8086 mode, is irrelevant isn't it?

Yes, but a 32-bit DOS would be pretty cool in my opinion. It's also odd he's using GRUB to boot a 16-bit kernel.

Vik2015 · **Joined:** Fri Sep 20, 2013 2:34 am **Posts:** 15

omarrx024 wrote:

It's also odd he's using GRUB to boot a 16-bit kernel.

Ahem, I was following the Bare Bones tutorial (found on the wiki) when I got the idea of writing something like MS DOS. So I didn't really care about the bootloader, but went straight into OS development.

P. S. Is there something wrong with using GRUB for this task? Or is it better to write my own bootloader? (I'd have to somehow parse ELF format and load it into the memory :shock:

)

iansjack · **Posted:** Fri Feb 06, 2015 9:15 am

omarrx024 wrote:

Yes, but a 32-bit DOS would be pretty cool in my opinion.

In which case we're back to "write a proper driver".

Vik2015 · **Joined:** Fri Sep 20, 2013 2:34 am **Posts:** 15

iansjack wrote:

omarrx024 wrote:

Yes, but a 32-bit DOS would be pretty cool in my opinion.

In which case we're back to "write a proper driver".

As I said I want to try to use no (or minimal) BIOS calls

. Thought that means implementing keyboard driver, etc. Again, that's the fun!

sortie · **Joined:** Wed Mar 21, 2012 3:01 pm **Posts:** 930

See also http://wiki.osdev.org/Meaty_Skeleton.

Kevin · **Posted:** Fri Feb 06, 2015 11:31 am

omarrx024 wrote:

I am also gonna *try* to write it using only real mode (64kb memory should be enough I guess?) but without using any BIOS calls (or just minimal amount of them).

That doesn't make a lot of sense. Why would you restrict yourself to Real Mode if you're not even using the BIOS, which is probably the only thing in RM that could possibly be seen as an advantage?

And being 16 bit isn't the defining property of DOS, in my opinion. You can probably still be quite DOS-like in Protected Mode. You wouldn't make any use of the protection features, of course, but having a much larger address space would definitely be worth it.

Vik2015 · **Joined:** Fri Sep 20, 2013 2:34 am **Posts:** 15

Kevin wrote:

omarrx024 wrote:

I am also gonna *try* to write it using only real mode (64kb memory should be enough I guess?) but without using any BIOS calls (or just minimal amount of them).

That doesn't make a lot of sense. Why would you restrict yourself to Real Mode if you're not even using the BIOS, which is probably the only thing in RM that could possibly be seen as an advantage?

And being 16 bit isn't the defining property of DOS, in my opinion. You can probably still be quite DOS-like in Protected Mode. You wouldn't make any use of the protection features, of course, but having a much larger address space would definitely be worth it.

Hmm. I guess you are right. Going to Protected Mode isn't going to hurt

. Gonna implement it after I finish reading meaty skele.

Kevin · **Posted:** Fri Feb 06, 2015 2:44 pm

Multiboot kernels are always started in Protected Mode by the bootloader. So unless you switch back to Real Mode (and I don't see any code to do that in your repository), you're automatically in PM.

Vik2015 · **Joined:** Fri Sep 20, 2013 2:34 am **Posts:** 15

Kevin wrote:

Multiboot kernels are always started in Protected Mode by the bootloader. So unless you switch back to Real Mode (and I don't see any code to do that in your repository), you're automatically in PM.

Oh. That's why QEMU was going crazy when I tried to use interrupts

I guess all that stuff is on the wiki... Gonna read more.

P. S. @Sortie, thanks for the tutorial! It really helped alot in organizing my project and developing some kind of libc for my kernel!

ExeTwezz · **Joined:** Sun Sep 21, 2014 7:16 am **Posts:** 104

Vik2015 wrote:

Gitrepo is here https://github.com/Vik2015/weevil/.

Storing the address of the repo in your signature is a good idea, what do you think?
User Control Panel -> Profile -> Edit signature

Vik2015 · **Joined:** Fri Sep 20, 2013 2:34 am **Posts:** 15

ExeTwezz wrote:

Vik2015 wrote:

Gitrepo is here https://github.com/Vik2015/weevil/.

Storing the address of the repo in your signature is a good idea, what do you think?
User Control Panel -> Profile -> Edit signature

Indeed. Added it to the signature

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