Hex editor to directly edit device contents
I'm currently taking an interest in the ext4 filesystem and have set up a small partition to allow me to play around with mke2fs and tune2fs.
To view the device raw data, I have been working in read-only, using the dd command to generate a file of the device contents which I then view using Okteta.
Is there any good GUI hex editor out there that will allow me to have read-write access to the contents of the device directly? That would allow me, for example, to directly change flag values in the superblock without having to go through tune2fs.