Re: 512 byte boot.img

[k2011gen]

On Fri, 14 Jan 2011 23:11:45 -0500
Felix Miata <address@hidden> wrote:

> On 2011/01/14 22:11 (GMT-0500) address@hidden composed:
> 
> >> From the grub2 manual
> 
> > boot.img
> >      On PC BIOS systems, this image is the first part of GRUB to start. It 
> > is written to a master boot record (MBR) or to the boot sector of a 
> > partition. Because a PC boot sector is 512 bytes, the size of this image is 
> > exactly 512 bytes.
> 
> > I always thought that the 512 byte MBR also includes the Partition-Table. 
> > So with the boot.img being 512 bytes and being written to the disk root 
> > sector what happens to the PT?
> 
> Grub boot sector code does not occupy 512 bytes. Installation involves 
> merging the existing partition table into the image before it gets written to 
> the target sector so that the table will appear to have been left untouched. 
> It's magic. :-)


That's what I suspected, thanks. Maybe the manual could outline that too.  

Isn't it possible to write less then a full sector into a sector?  I thought dd 
could do that.




> -- 
> "How much better to get wisdom than gold, to choose
> understanding rather than silver." Proverbs 16:16 NKJV
> 
>   Team OS/2 ** Reg. Linux User #211409
> 
> Felix Miata  ***  http://fm.no-ip.com/
> 
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