device drivers and the linux kernel
I'm bulding this embedded linux application. I have the linux kernel running on an ARM processor... (the sharp LH79520 SoC)... Now I need to get a device driver for an SDcard... It is connected to the Sychnronous Serial ports (I have the pin numbers).. As i understand it, i'll use the SPI protocol when accessing the SDcard...
What i don't know is whether i'll need to write the device driver from scratch (as in write it when i'm running linux on the board), or i can find a device driver on the net that i can modify to suit my board and incorporate into the kernel before downloading it onto the board and booting it... The linux kernel that i have has some device drivers but none are for the SPI protocol or the SD card in particular..
also i don't know about the filesytem... is a device driver specific to a filesystem?
Any help or even pointers would be really welcome!