Last night’s hacking progress was targeted at getting the SD/MMC driver up and running. Since the PXA27x platform has built-in SD/MMC support, it’s just a matter of setting up the SD/MMC communication GPIOs (clock, data, command channel) and locating the GPIOs for detecting SD card insertion events and read-only status.
I haven’t managed to get the SD card driver working on my phone, but I think it has something to do with my SD card. One of the testers on the IRC channel got it to mount his 512MB high-speed SD card correctly.
The problem is that the data received from the SD card seems to fail its CRC check. The errata for the PXA platform indicates that there might be trouble with some SD cards at certain speeds. Since the card works fine in PalmOS and the bootloader, I’m guessing that I might just need to add a retry or delay at some point until the SD card is ready to go.
Yeah, it looks like the pxamci driver is really dodgy. Lots of people have reported to me problems using various different cards. One guy said he had 10 different cards and was going to try them all and email me the results so we could start a list of what works and what doesn’t. Even with working cards most people (myself included) find access times really slow, and every now and then the driver spits out some errors.