Re: [Qemu-devel] [PATCH 0/4] Add multiboot support (x86) v2

[Kevin Wolf <kwolf@redhat.com>]

François Revol schrieb:
>> Why would an OS want to parse multiboot structures but not implement
>> proper multiboot support? I mean, this really isn't anything
>> complicated. When you have enabled it to understand multiboot 
>> structures
>> you are only missing a handful of bytes for the multiboot header.
>>
>> What is it that you need to do differently for Haiku?
> 
> Because Haiku has its own second stage loader, which requires the BIOS 
> to locate the kernel and module in a BFS partition which grub doesn't 
> implement btw.

That makes sense on real hardware, of course. But for -kernel you don't
need a file system to read the kernel from.

I'm not talking about replacing the existing loader, but just about
adding support for multiboot as an additional option. Don't know how the
Haiku boot process works though, so maybe I'm completely wrong.

> It also handles PM switching by itself.
> Haiku might also use the BIOS for other stuff, like VESA mode 
> switching, so I'd need to make sure all calls aren't strictly required.

In theory you could switch back to Real Mode when starting through
multiboot and then continue as with a normal boot. Admittedly, doesn't
sound exactly nice, but should be doable...

Kevin