On Saturday 22 December 2007 10:03, Bean wrote: > 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.
Thank you for your information. In my estimate, LZMA will outperform, if the ratio, compressed size : original size, is less than 0.52. So LZMA might win. :) Okuji _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
