Re: R: Re: R: Re: R: Re: CAN BIOS/UEFI DO WRITING OPERATIONS ON ATTACHED DRIVES BY MEANS OF INT 13 H INTERRUPT ?

[Colin Watson]

On Mon, Jul 24, 2017 at 11:25:31AM +0200, address@hidden wrote:
> You has been very clear about the GRUB design.
> 
> Please, let me pose another question, because i see you have a solid 
> experience and you are precise.
> 
> Do you know if the Ubuntu kernel uses BIOS services, in particular the INT 
> 13H interrupt, or if it is BIOS indipendent ? In this last case in which a 
> way Ubuntu treats the low-level disk services ?
> 
> If I well understood Ubuntu should intercept the call and passes it to the 
> operating system's native disk I/O mechanism, bypassing BIOS routines for the 
> low-level disk reading/writing access.

I'm afraid that I'm not a kernel developer and can't answer this with
any authority.

My understanding is that the Linux kernel typically doesn't use BIOS
services for disk I/O since it's running in protected mode, but it's
possible that there are some edge cases where this isn't true.  You'd
need to find an actual kernel developer to be authoritative about this,
though.

-- 
Colin Watson                                       address@hidden