Part 1 is, implement
- M20: List SD card.
- M21: Initialize SD card (has to be done before listing).
- M22: Release SD card.
Do all this in one chunk, splitting this up wouldn't allow to test
the result.
This is all the commands to read from and write to SPI,
initializing the card, read in blocks and so on. This should
make Petit FatFs actually usable.
So far read-only and no M-codes to let end users play with
this stuff.
The demonstration code was changed to list the SD card's
top level directory over and over again.
Some modifications to avoid file name conflicts with other parts and
make it compile. As the glue code to the hardware (spi.c/.h) is
still missing, there are a few warnings, of course.
Changes to this library are tracked in pff.c.
Michael Moon
Markus Hitter