Create a partition on SD card for ext4 filesystem I've got an SD card and want to create a partition on it for the ext4 fs.
The partition must start after 1MB. This 1MB will be used for a bootloader (u-boot).
I'm doing this on OS X Yosemite.

Here's what I do and get:

macbook@terminalx:cubie $ diskutil partitionDisk disk3 2 "Free Space" "%noformat%" 1M "Free Space" "%noformat%" R                                                                                    
Started partitioning on disk3
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Finished partitioning on disk3
/dev/disk3
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *4.0 GB     disk3
   1:                        EFI EFI                     209.7 MB   disk3s1


The result is not what I expect at all. In my mind it must be something like two partitions with no format. First is 1MB and the second is all left free space on the SD card.

How can I achieve this?

Thank you.
OS X cannot see ext partitions. You would be better to do this on Linux.

You can install support e.g OS X Fuse as outlined in http://osxdaily.com/2014/03/20/mount-ext-linux-file-system-mac/

You will also need FUSE-Ext2 as https://github.com/osxfuse/osxfuse/wiki/Ext

I am not sure if this will allow you to create ext4 partitions, but you can certainly mount them.