| #!/bin/sh |
| # SPDX-License-Identifier: 0BSD |
| # |
| # This is a wrapper for xz to compress the kernel image using appropriate |
| # compression options depending on the architecture. |
| # |
| # Author: Lasse Collin <lasse.collin@tukaani.org> |
| |
| BCJ= |
| LZMA2OPTS= |
| |
| case $SRCARCH in |
| x86) BCJ=--x86 ;; |
| powerpc) BCJ=--powerpc ;; |
| arm) BCJ=--arm ;; |
| sparc) BCJ=--sparc ;; |
| esac |
| |
| # Use single-threaded mode because it compresses a little better |
| # (and uses less RAM) than multithreaded mode. |
| # |
| # For the best compression, the dictionary size shouldn't be |
| # smaller than the uncompressed kernel. 128 MiB dictionary |
| # needs less than 1400 MiB of RAM in single-threaded mode. |
| # |
| # On the archs that use this script to compress the kernel, |
| # decompression in the preboot code is done in single-call mode. |
| # Thus the dictionary size doesn't affect the memory requirements |
| # of the preboot decompressor at all. |
| exec $XZ --check=crc32 --threads=1 $BCJ --lzma2=$LZMA2OPTS,dict=128MiB |
