1 files changed, 7 insertions, 1 deletions

diff --git a/meta/classes/image_types.bbclass b/meta/classes/image_types.bbclass
index 4d928667e8..2e852af70a 100644
--- a/meta/classes/image_types.bbclass
+++ b/meta/classes/image_types.bbclass
@@ -316,7 +316,13 @@ IMAGE_TYPES = " \
     wic wic.gz wic.bz2 wic.lzma \
 "
 
-CONVERSIONTYPES = "gz bz2 lzma xz lz4 zip sum md5sum sha1sum sha224sum sha256sum sha384sum sha512sum bmap"
+# Compression is a special case of conversion. The old variable
+# names are still supported for backward-compatibility. When defining
+# new compression or conversion commands, use CONVERSIONTYPES and
+# CONVERSION_CMD/DEPENDS.
+COMPRESSIONTYPES ?= ""
+
+CONVERSIONTYPES = "gz bz2 lzma xz lz4 zip sum md5sum sha1sum sha224sum sha256sum sha384sum sha512sum bmap ${COMPRESSIONTYPES}"
 CONVERSION_CMD_lzma = "lzma -k -f -7 ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}"
 CONVERSION_CMD_gz = "gzip -f -9 -c ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type} > ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}.gz"
 CONVERSION_CMD_bz2 = "pbzip2 -f -k ${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.${type}"