Re: Creating grub/grub2/grldr.mbr bootrom with makerom

[Robert Millan]

On Sat, Dec 22, 2007 at 02:50:11AM +0800, Bean wrote:
> makerom is a new tool in the GRUB Utilities project. It can be used to
> create bootrom image using grub legacy, grub2 and grldr.mbr.
> 
> grub legacy/grub4dos:
> makerom rom_xxx.img stage2 grub.bin
> 
> grub2:
> makerom rom_xxx.img core.img grub2.bin
> 
> grldr.mbr:
> makerom -s 0 rom_xxx.img grldr.mbr grldr.bin
> 
> rom_xxx.img stands for one of the following files:
> 
> rom_isa.img: Header for ISA bootrom
> rom_pci.img: Header for PCI bootrom
> rom_zisa.img: Header for ISA bootrom, support lzma decompression
> rom_zpci.img: Header for PCI bootrom, support lzma decompression
> 
> To enable lzma, you should use option -z, and choose one of the
> headers that supports lzma:
> 
> makerom -z rom_zisa.img stage2 grub.bin
> 
> As bootrom has 64K size limit, for image larger than 64K, you must use
> compression. For example, the uncompressed stage2 for grub 0.97 is
> 98K, after compression, image reduced to about 50K.
> 
> Also note that compression is performed by external lzma program, you
> need to install the lzma package before using the compression
> function.

How well does compression work for GRUB 2 ?  core.img is already compressed
(with lzo); if LZMA makes better results perhaps it'd be a good idea to switch.

-- 
Robert Millan

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