Is OSDev using HLA possible?

[DarkWolf]

grub allows you to load a kernel image directly.  but the kernel has to live in 1mb+

Heh ??

I may have forgotten what you are referring to.
Are you talking about the size of the kernel or it's location in memory ?

[Sevag.K]

Location in memory.

[hackerlabs]

Yep.
I have to make sure that it's located exactly where it's supposed to be - which means 16-bit assembler.

Ugh  :'(

[DarkWolf]

Location in memory.

That's what I thought you meant.
So I quess what I am asking is why does that still require 16 bit code ?

Aside from controlling your own bootloader, why couldn't someone use GRUB for booting and write a 32bit OS with HLA ?

[hackerlabs]

Location in memory.

That's what I thought you meant.
So I quess what I am asking is why does that still require 16 bit code ?

Aside from controlling your own bootloader, why couldn't someone use GRUB for booting and write a 32bit OS with HLA ?

Okay.
Here's the thing. When a x86 processor is switched on, it's always in real mode - that is, 16 bits.
Intel designed the processor in this manner, to retain compatibility with the 8086.
So, when you write the bootloader, you write it in 16-bit assembly. Then, you switch over to protected mode, and then utilize all the benefits of 32-bit code  :wink

As for using GRUB, yeah, that's possible.
You need to include a multi-boot header in the kernel, so that GRUB recognizes it as a multi-boot compliant kernel, and boots it properly.
That is something which can be easily achieved with HLA code, so...good luck  :U

[Sevag.K]

Location in memory.

That's what I thought you meant.
So I quess what I am asking is why does that still require 16 bit code ?

Aside from controlling your own bootloader, why couldn't someone use GRUB for booting and write a 32bit OS with HLA ?

i'm not an expert in this, but as far as i know, if you use grub, you can configure it to load your kernel directly (without a 16bit boot loader) into memory that's located at 1 MB or higher in physical memory.  my guess is that grub needs that 1st 1 mb of physical memory for itself.

[hackerlabs]

Location in memory.

That's what I thought you meant.
So I quess what I am asking is why does that still require 16 bit code ?

Aside from controlling your own bootloader, why couldn't someone use GRUB for booting and write a 32bit OS with HLA ?

i'm not an expert in this, but as far as i know, if you use grub, you can configure it to load your kernel directly (without a 16bit boot loader) into memory that's located at 1 MB or higher in physical memory.  my guess is that grub needs that 1st 1 mb of physical memory for itself.

Shoot. I forgot to mention that.
You just need to take care of two things:
1) The Multi-boot header.
2) Placing the kernel at 1MiB or higher.

That should do the trick  :thumbu