On 04/25/2019 02:37 PM, Adam Borowski wrote:
On Tue, Apr 23, 2019 at 02:20:43PM +0000, Christophe Leroy wrote:
This patch allows to generate bzip2 compressed uImage
Please don't add bzip2 support, that's a waste of your time as we're trying
to remove it kernel-wide. There's a patchset to retire compressors beaten
by alternatives on the whole speed-to-size curve; reposting it is overdue.
It does:
* add ZSTD (fast and strong)
* remove BZIP2 (obsolete, only user in kernel)
* remove LZMA (redundant with XZ, uses a private copy of its library)
* makes Kconfig prose talk badly about LZO (used elsewhere in the kernel)
I believe only three compressors are worth using here: XZ, ZSTD, LZ4.
GZIP must stay because of ubiquitous support, the rest should go.
Ok. Initially the purpose was to add lzma, then I took the opportunity
to add all compressors supported by u-boot uImage files which are 'none,
bzip2, gzip, lzma, lzo':
[root@po16846vm linux-powerpc]# mkimage -C -h
Invalid Compression Type - valid names are: none, bzip2, gzip, lzma, lzo
Usage: mkimage -l image
-l ==> list image header information
mkimage [-x] -A arch -O os -T type -C comp -a addr -e ep -n name
-d data_file[:data_file...] image
So I can leave bzip2 aside.
xz, zstd and lz4 are not supported by the uImage format as far as I know
so we have to keep lzma which gives a far better compression ratio than
gzip (gzipped uImage don't fit in my board's NOR Flash while lzmaed
uImage does).
Christophe
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -199,6 +199,7 @@ config PPC
+ select HAVE_KERNEL_BZIP2 if DEFAULT_UIMAGE
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -23,6 +23,7 @@ all: $(obj)/zImage
+compress-$(CONFIG_KERNEL_BZIP2) := CONFIG_KERNEL_BZIP2
@@ -259,6 +260,7 @@ endif
+compressor-$(CONFIG_KERNEL_BZIP2) := bz2
--- a/arch/powerpc/boot/wrapper
+++ b/arch/powerpc/boot/wrapper
@@ -137,7 +137,7 @@ while [ "$#" -gt 0 ]; do
- [ "$1" != "gz" -o "$1" != "xz" -o "$1" != "lzma" -o "$1" != "none" ]
|| usage
+ [ "$1" != "gz" -o "$1" != "xz" -o "$1" != "lzma" -o "$1" != "bz2" -o "$1" !=
"none" ] || usage
@@ -149,6 +149,9 @@ while [ "$#" -gt 0 ]; do
+ if [ $uboot_comp = "bz2" ]; then
+ uboot_comp=bzip2
+ fi
@@ -377,6 +380,9 @@ if [ -z "$cacheit" -o ! -f "$vmz$compression" -o
"$vmz$compression" -ot "$kernel
+ .bz2)
+ bzip2 -f "$vmz.$$"
+ ;;
Meow!
