For the last several days I'm trying to make RPi and Windows recognize different partitions on the SD card. What I would like to achieve, is to be able to collect some scientific data when RPi is booted and running and write it to the second partition of the SD (UDF filesystem, works for both Linux and Windows). Then, insert this card to a Windows machine and be able to directly read the files in the second partition. I can't use single partition, since RPi boots only from FAT and I need to collect data larger than 4GB.
The problem is that RPi can only boot from the first partition and at the same time Windows only sees first partition of a removable device. I tried several different approaches, including hidding a partition, changing order, type, etc., but the result is always the same (RPi boot and Windows always see the same partition).
I know that there are some hacks to force Windows to read the second partition, but they are dirty and works only on the hacked machine. I could use ext2 filesystem, but I would need ext2 drivers to be installed on the target Windows machine, which, again is not the ideal solution I'm looking for.