Re: [PATCH] doc: document config_directory and config_file variables

[Andrei Borzenkov]

08.11.2015 01:58, Arbiel (gmx) пишет:
> > > undocumented command parameter : --hint (command search), and some other
> > > --hint.something which I haven't been able to localise just now.
> >
> > Which command?
> search.
> And I just read in a grub.cfg file, not one of mine the line
>
> search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt6 
> --hint-efi=hd0,gpt6 --hint-baremetal=ahci0,gpt6  
> 427b86fb-cc66-46be-ad68-ade86794af55
>
> which shows some "--hint" parameters. What do they all mean ?

They are intended to optimize search at boot time. They contain guessed 
firmware device names. If this name was guessed correctly, it avoids 
searching across all devices at boot time.

In practice for Linux on i386-pc it does not really work because to 
reliably guess BIOS HDD number you need EDD and with 32 bit Linux boot 
protocol EDD information must be provided by bootloader.

This is again something that users should not be normally concerned with 
- these hints are added automatically by probing code. We could add "see 
development manual for additional options" if we had development manual 
... but yes, description of grub-mkconfig framework and which high-level 
functions are provided is missing.