[PATCH] feat: add zstd support to image conversions

[Michael Adler <michael.adler@siemens.com>]

This patch enables ISAR to build zstd compressed images.

Signed-off-by: Michael Adler <michael.adler@siemens.com>
---
 meta/classes/imagetypes.bbclass | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/meta/classes/imagetypes.bbclass b/meta/classes/imagetypes.bbclass
index 1e8e223d..6950da7a 100644
--- a/meta/classes/imagetypes.bbclass
+++ b/meta/classes/imagetypes.bbclass
@@ -93,7 +93,7 @@ IMAGE_CMD_ubi() {
 IMAGE_CMD_ubi[depends] = "${PN}:do_transform_template"
 
 # image conversions
-IMAGE_CONVERSIONS = "gz xz"
+IMAGE_CONVERSIONS = "gz xz zst"
 
 CONVERSION_CMD_gz = "${SUDO_CHROOT} sh -c 'gzip -f -9 -n -c --rsyncable ${IMAGE_FILE_CHROOT} > ${IMAGE_FILE_CHROOT}.gz'"
 CONVERSION_DEPS_gz = "gzip"
@@ -105,3 +105,11 @@ XZ_OPTIONS ?= "--memlimit=${XZ_MEMLIMIT} --threads=${XZ_THREADS}"
 XZ_OPTIONS[vardepsexclude] += "XZ_MEMLIMIT XZ_THREADS"
 CONVERSION_CMD_xz = "${SUDO_CHROOT} sh -c 'xz -c ${XZ_OPTIONS} ${IMAGE_FILE_CHROOT} > ${IMAGE_FILE_CHROOT}.xz'"
 CONVERSION_DEPS_xz = "xz-utils"
+
+ZST_LEVEL ?= "19"
+ZST_THREADS ?= "${@oe.utils.cpu_count(at_least=2)}"
+ZST_THREADS[vardepvalue] = "1"
+ZST_OPTIONS ?= "-${ZST_LEVEL} --threads=${ZST_THREADS}"
+ZST_OPTIONS[vardepsexclude] += "ZST_LEVEL ZST_THREADS"
+CONVERSION_CMD_zst = "${SUDO_CHROOT} sh -c 'zstd -c ${ZST_OPTIONS} ${IMAGE_FILE_CHROOT} > ${IMAGE_FILE_CHROOT}.zst'"
+CONVERSION_DEPS_zst = "zstd"
-- 
2.39.1