On Dec 22, 2007 4:06 PM, Yoshinori K. Okuji <[EMAIL PROTECTED]> wrote: > On Friday 21 December 2007 20:04, Robert Millan wrote: > > 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. > > It's not that simple. LZO was chosen instead of gzip, because of the size > requirement on PC. To preserve safety, we need to keep the core part less > than 31.5KB (63 sectors). > > The size is the sum of non-compressable bootstrap code, decompression code and > compressed code + data. When I made an experiment in PUPA, although gzip had > a better compression ratio, due to the decompression code size, LZO won. > > I don't know precisely, but I suspect that decompression code for LZMA would > be slightly larger than gzip's (IIRC, a range coder is likely to require more > code and data). So I don't expect that LZMA can replace the current usage of > LZO in normal PC so easily.
The decompression code for LZMA is very small, i use -Os option to compile LzmaDecode.c, the result is about 2.8K. -- Bean _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
