Image idea

On a phone, my computer’s busy building Firefox.

Windows probably doesn’t understand ext2/3/4 unless you’ve added something.

dd can make images but they’ll include empty blocks. What if you: make and format your / and /boot partitions on a small SD. Image it with dd. Now loop mount the image and use something like piclone to copy your files into it. Will the image expand? Piclone uses cp to copy just files, not empty blocks. Might make small efficient images.

Windows probably doesn't understand ext2/3/4 unless you've added something.

There is an EXT2 driver for Windows, I was using it successfully in
Windows 7 with EXT3 until an update broke it (I don't use Windows often
enough to pursue it):

http://www.fs-driver.org/

There's also a BTRFS driver (untested by me):
https://github.com/maharmstone/btrfs

That said, I'm beyond caring about that legacy OS.

dd can make images but they'll include empty blocks. What if you: make and format your / and /boot partitions on a small SD. Image it with dd. Now loop mount the image and use something like piclone to copy your files into it. Will the image expand? Piclone uses cp to copy just files, not empty blocks. Might make small efficient images.

`dd conv=sparse` will seek past long blocks of NULLs. This will though,
drag in blocks of data that have been "deleted" but not erased. It
probably also won't recognise 0xff as erased data either (sub-optimal
for flash, but workable).

`cp` doesn't sound like the best tool for this; `cpio` or `tar` would be
better. Essentially you need something that, on cretinous operating
systems that don't support EXT4, will read the files from the archive
and write those into the EXT4 filesystem.

I suggest `tar`, as it's widely available and well understood.