ICS eMMC images do not support the microSD card slot by default

When running on an eMMC image you'll notice that you can't eg. download stuff with the browser as it thinks there is no microSD card present even if you actually do.

The inserted card is not mounted because /etc/vold.fstab has this line:

dev_mount sdcard /mnt/sdcard 6 /devices/sdi0/mmc_host/mmc1/mmc1

which instructs vold to use partition 6 of the card as the sdcard storage. This is correct for the scenario where booting is done on microSD, in which a partition is used to "simulate" the card slot having a card.

However, with eMMC this is not really the case unless you want to create a microSD card with 6 partitions. But that would not be compatible with plugging in a card used with your camera/phone/mediaplayer (which I'd imagine being the #1 use-case for this).

The fix is simple of course; just unpack system.tar.bz2, change the partition to 1 or auto to use the first or the first usable (meaning vfat) partition, respectively. This is what will be done for the prebuilt eMMC image published at igloocommunity.org.

However, I can't help thinking that this is already the second hack preventing a smooth path from boot/system/userdata tarballs to an eMMC image related to partitions. Surely there must be a way to change these things eg. as a part of the LAMC process or something else we could do to make this less painful?

If not, this can be closed as fixed (since it is after doing the change for future eMMC images) but it's important to have this info recorded.