xz_wrap.sh use $SRCARCH to detect the BCJ filter. However, assigning
arm BCJ filter to Thumb-2 kernel is not optimal. In my case, about 5%
decrease of image size is observed with armthumb BCJ filter:
Test results:
hardware: QEMU emulator version 3.1.0
config: vexpress_defconfig with THUMB2_KERNEL & KERNEL_XZ on
arm BCJ: 4029808
armthumb BCJ: 3827280
Choose armthumb BCJ filter for Thumb-2 kernel to make smaller images.
Signed-off-by: Jubin Zhong <zhongjubin@huawei.com>
Link: https://lore.kernel.org/lkml/1637323647-19988-1-git-send-email-zhongjubin@huawei.com/
Change-Id: I23c6e0fd2e54fdc84e78f122d6f4f06e54026696
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
83c382f436