powerpc/boot: Add lzma support for uImage

This patch allows to generate lzma compressed uImage

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Kconfig

@@ -198,6 +198,7 @@ config PPC
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK
 	select HAVE_KERNEL_GZIP
+	select HAVE_KERNEL_LZMA			if DEFAULT_UIMAGE
 	select HAVE_KERNEL_XZ			if PPC_BOOK3S || 44x
 	select HAVE_KPROBES
 	select HAVE_KPROBES_ON_FTRACE

arch/powerpc/boot/Makefile

@@ -22,6 +22,7 @@ all: $(obj)/zImage
 
 compress-$(CONFIG_KERNEL_GZIP) := CONFIG_KERNEL_GZIP
 compress-$(CONFIG_KERNEL_XZ)   := CONFIG_KERNEL_XZ
+compress-$(CONFIG_KERNEL_LZMA) := CONFIG_KERNEL_LZMA
 
 ifdef CROSS32_COMPILE
     BOOTCC := $(CROSS32_COMPILE)gcc
@@ -257,6 +258,7 @@ endif
 
 compressor-$(CONFIG_KERNEL_GZIP) := gz
 compressor-$(CONFIG_KERNEL_XZ)   := xz
+compressor-$(CONFIG_KERNEL_LZMA)   := lzma
 
 # args (to if_changed): 1 = (this rule), 2 = platform, 3 = dts 4=dtb 5=initrd
 quiet_cmd_wrap	= WRAP    $@

arch/powerpc/boot/wrapper

@@ -137,7 +137,7 @@ while [ "$#" -gt 0 ]; do
     -Z)
 	shift
 	[ "$#" -gt 0 ] || usage
-        [ "$1" != "gz" -o "$1" != "xz" -o "$1" != "none" ] || usage
+        [ "$1" != "gz" -o "$1" != "xz" -o "$1" != "lzma" -o "$1" != "none" ] || usage
 
 	compression=".$1"
 	uboot_comp=$1
@@ -374,6 +374,9 @@ if [ -z "$cacheit" -o ! -f "$vmz$compression" -o "$vmz$compression" -ot "$kernel
     .gz)
         gzip -n -f -9 "$vmz.$$"
         ;;
+    .lzma)
+        xz --format=lzma -f -6 "$vmz.$$"
+	;;
     *)
         # drop the compression suffix so the stripped vmlinux is used
         compression=