Hello,
I found some informations about your problem.
One of our customer asked this question and I think it's related.
"Where the File I/O fuctions are mapped into the ARM ? Using RAM memory?"
We use the RL-Flash driver from Keil: http://www.keil.com/support/man/docs/rlarm/rlarm_fs_flashfs.htm. They implement a two layer driver, the top layer is generic and is shipped as a lib - C:\Program Files\National Instruments\LabVIEW version\Targets\Keil\Embedded\RealView\Drivers\RL-ARM\FlashFS. The low level driver is shipped as source and is hardware dependent (Specific for each board). On the luminary, the interface to the SD card is implemented using SPI. THe driver is located at C:\Program Files\National Instruments\LabVIEW version\Targets\Keil\Embedded\RealView\hardware\Template\Drivers\FlashFS
I hope it helps,
Regards,
MatthieuR