Hi Stefan, Tom,

I'm using genext2fs command in Linux to generate my boot image for kernel and its dtb, my command is like this: $ genext2fs -b 32768 -B $((32*1024*1024/32768)) -d boot/ -i 8192 -U boot.img

In the latest version of U-Boot, the image from above command is not able to be mount. After debug, I found out that the root cause is that the genext2fs does not have a initial value for revision_level in super block. After I do the mount and umount for the image in Linux, the U-Boot then can mount the image.

Is it possible to still support the ext2 image generated by genext2fs command in U-Boot?

Thanks, - Kever On 09/17/2016 08:10 AM, Stefan Brüns wrote:

If EXT4_FEATURE_INCOMPAT_64BIT is set, the descriptor can be read from the superblocks, otherwise it defaults to 32.

Signed-off-by: Stefan Brüns stefan.bruens@rwth-aachen.de

fs/ext4/ext4_common.c | 18 ++++++++++++++---- include/ext4fs.h | 2 ++ 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index a78b0b8..416a9db 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -2233,13 +2233,23 @@ int ext4fs_mount(unsigned part_length) goto fail; }

• if (le32_to_cpu(data->sblock.revision_level) == 0)

• if (le32_to_cpu(data->sblock.revision_level) == 0) { fs->inodesz = 128;

• else

• } else {

• debug("EXT4 features COMPAT: %08x INCOMPAT: %08x RO_COMPAT: %08x\n",
  

•       __le32_to_cpu(data->sblock.feature_compatibility),
  

•       __le32_to_cpu(data->sblock.feature_incompat),
  

•       __le32_to_cpu(data->sblock.feature_ro_compat));
  

• fs->inodesz = le16_to_cpu(data->sblock.inode_size);

• fs->gdsize = le32_to_cpu(data->sblock.feature_incompat) &
  

• 	EXT4_FEATURE_INCOMPAT_64BIT ?
  

• 	le16_to_cpu(data->sblock.descriptor_size) : 32;
  

• }

• debug("EXT2 rev %d, inode_size %d\n",

•       le32_to_cpu(data->sblock.revision_level), fs->inodesz);
  

• debug("EXT2 rev %d, inode_size %d, descriptor size %d\n",

•      le32_to_cpu(data->sblock.revision_level),
  

•      fs->inodesz, fs->gdsize);
  
  

  data->diropen.data = data; data->diropen.ino = 2;

diff --git a/include/ext4fs.h b/include/ext4fs.h index 6e31c73..7e1ee6c 100644 --- a/include/ext4fs.h +++ b/include/ext4fs.h @@ -87,6 +87,8 @@ struct ext_filesystem { uint32_t inodesz; /* Sectors per Block */ uint32_t sect_perblk;

• /* Group Descriptor size */
• uint16_t gdsize; /* Group Descriptor Block Number */ uint32_t gdtable_blkno; /* Total block groups of partition */