[maemo-developers] Howto correctly place data on the memory card?

[From: Till Harbaum / Lists]

Hi,

i several of my projects i face the same problem: How do i correctly add
bulk data on the internal memory card?

Up to stock diablo everything was simple: The entire card was mounted 
as vfat on /media/mmc2 and my applications moved their data there (e.g. /media/mmc2/osm2go).

But with the arrival of fremantle things have changed. The card now seems
to be mounted with ext3 on /home/user and a bigger partition with vfat
under /home/user/MyDocs. Now i have a bunch of problems:

- How do i correctly figure out i am compiling for fremantle?
  I am currently using "pkg-config --modversion maemo-version" and parse
  the result in configure. This seems to be pretty stable and useful. Ok?

- How do i correctly figure out i am running on fremantle?
  My currently solution is to check the environment variable
  "OSSO_PRODUCT_RELEASE_NAME" which is "Maemo 5" for fremantle.
  Is this ok? How do i deal with the scratchbox? It doesn't seem to set
  this variable at all.

- How do i correctly find the big vfat partition in fremantle? It seems to
  be mounted under /home/user/MyDocs. Unfortunately that place doesn't
  even exist in scratchbox (unless you user name there is "user"). So
  how do i know i am running in scratchbox and need to /home/user? 
  Using $HOME seems critial in e.g. postinst as the installation my be
  run by the root user.

So the question basically is: How does the build environment find the path
to the big vfat memcard location and how does e.g. a postinst script
find the same location at installation time?

Till