Put onto the mmc card:
insmod
rmmod
lsmod
sdio_busdriver.ko
sdio_local_bus.ko
sdio_generic_function.ko
bdtest
armld.scr
armunld.scr
armfnld.scr


Boot the system, log in and switch to
#cd /mnt/mmc
Load the modules using
#./armld.scr
You should get a few messages, like the major number displayed. 
To debug messages use:
#dmesg
You'll get lots of debug, with our stuff at the end. You can use this at anytime.
To force a card inseration, you can use the test application. 
This will send IOCTL to the local bus driver telling it to announce the arrival of a certain card.
The bus driver will then look for a function driver and find sdio_generic_functiom has refistered for this card.
The bus driver will call the function drivers probe. This function will acept the card.
#bdtest -i

Do a dmesg and you'll see what went on.

This should give you enough to excercise the infrastructure.