10-15-2012 09:20 AM
I want to use an SDXC/SDHC memory card on an zynq in a bare-metal application.
(my card would be pre formated, and i read the flash to know where i write my data)
I would like to know if I can find a low level C libraries that initalize the card in high speed mode and acces to the SD card memory .
i do not want to write the hole driver.
10-20-2012 09:39 PM
03-13-2013 08:48 AM
I'm writing a small RTOS based on FreeRTOS for Zynq, and I am also having the same problem... there simply is not much information on SDHCI. The simplified specs are basically useless unless you already know a lot about SDCards.
The nice thing is that the controller conforms to SDHCI standard, and so there are a few open-source drivers that implement basic sdcard access. E.g. raspberry pi....
Checkout -- https://github.com/jameswalmsley/rpi-boot/blob/master/emmc.c (I forked it on github and using to help me write a fully featured driver).
If you're interested in a fully featured driver, checkout http://github.com/jameswalmsley/bitthunder/ in 2/3 weeks from now.
You need to look under driver/mmc/host/sdhci.c
It seems there's no support from Xilinx for doing this either, they basically expect you to use their FSBL, which is pretty slow at SDcard access, or linux.
Hope this helps,