Add support for erofs filesystems

Since Linux 5.4 a new read-only filesystem is available, erofs.
Compared to squashfs it offers much better read performance with and
without compression enabled.
It suppports two optional compressors, lz4 and lz4hc.

>From the mkfs.erofs man page:
EROFS is a new enhanced lightweight linux read-only filesystem with
modern designs (eg. no buffer head, reduced metadata, inline
xattrs/data, etc.) for scenarios which need high-performance read-only
requirements, e.g. Android OS for smartphones and LIVECDs.
It also provides fixed-sized output compression support, which improves
storage density, keeps relatively higher compression ratios, which is
more useful to achieve high performance for embedded devices with
limited  memory since it has unnoticable memory overhead and page cache
thrashing.

This commit adds support for three new filesystem targets:
erofs: erofs without compression
erofs-lz4: erofs with lz4 compresssion enabled
erofs-lz4hc: erofs with lz4hc compression enabled

(From OE-Core rev: 41dead1ff8ccc49e6cd6e6f5d41a59d164693e0d)

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/meta/classes/image_types.bbclass b/meta/classes/image_types.bbclass
index 8028691405..2a45d45c71 100644
--- a/meta/classes/image_types.bbclass
+++ b/meta/classes/image_types.bbclass
@@ -108,6 +108,11 @@ IMAGE_CMD_squashfs-xz = "mksquashfs ${IMAGE_ROOTFS} ${IMGDEPLOYDIR}/${IMAGE_NAME
 IMAGE_CMD_squashfs-lzo = "mksquashfs ${IMAGE_ROOTFS} ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.squashfs-lzo ${EXTRA_IMAGECMD} -noappend -comp lzo"
 IMAGE_CMD_squashfs-lz4 = "mksquashfs ${IMAGE_ROOTFS} ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.squashfs-lz4 ${EXTRA_IMAGECMD} -noappend -comp lz4"
 
+IMAGE_CMD_erofs = "mkfs.erofs ${EXTRA_IMAGECMD} ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.erofs ${IMAGE_ROOTFS}"
+IMAGE_CMD_erofs-lz4 = "mkfs.erofs -zlz4 ${EXTRA_IMAGECMD} ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.erofs-lz4 ${IMAGE_ROOTFS}"
+IMAGE_CMD_erofs-lz4hc = "mkfs.erofs -zlz4hc ${EXTRA_IMAGECMD} ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.erofs-lz4hc ${IMAGE_ROOTFS}"
+
+
 IMAGE_CMD_TAR ?= "tar"
 # ignore return code 1 "file changed as we read it" as other tasks(e.g. do_image_wic) may be hardlinking rootfs
 IMAGE_CMD_tar = "${IMAGE_CMD_TAR} --sort=name --format=posix --numeric-owner -cf ${IMGDEPLOYDIR}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.tar -C ${IMAGE_ROOTFS} . || [ $? -eq 1 ]"
@@ -243,6 +248,9 @@ do_image_ubi[depends] += "mtd-utils-native:do_populate_sysroot"
 do_image_ubifs[depends] += "mtd-utils-native:do_populate_sysroot"
 do_image_multiubi[depends] += "mtd-utils-native:do_populate_sysroot"
 do_image_f2fs[depends] += "f2fs-tools-native:do_populate_sysroot"
+do_image_erofs[depends] += "erofs-utils-native:do_populate_sysroot"
+do_image_erofs_lz4[depends] += "erofs-utils-native:do_populate_sysroot"
+do_image_erofs_lz4hc[depends] += "erofs-utils-native:do_populate_sysroot"
 
 # This variable is available to request which values are suitable for IMAGE_FSTYPES
 IMAGE_TYPES = " \
@@ -261,6 +269,7 @@ IMAGE_TYPES = " \
     wic wic.gz wic.bz2 wic.lzma wic.zst \
     container \
     f2fs \
+    erofs erofs-lz4 erofs-lz4hc \
 "
 
 # Compression is a special case of conversion. The old variable