答复: SDHC driver of RTEMS

[Sebastian Huber]

On 2013-08-05 04:02, 芮正新 wrote:
> Hi Ric,
>    Do you found such problems on your driver?
>    The u-boot has the "fatload" command, I can use it to load RTEMS image(about 4MB size) from SD card, and it's has no error.
>    I know the u-boot use poll method, but it should not be the reason.

At least the eSDHC controller on the P1020 had some silicon bugs which needed
workarounds for the DMA mode.

At the time I wrote the QorIQ BSP the chip was relatively new and not all bugs
were in the errata document, but the Linux driver was a good documentation
source.  I tried to use the SDHC framework from FreeBSD, but it didn't fit well
with the silicon bugs, so in the end we used a custom driver not committed to
the main RTEMS sources.

After the network stack update we have enough FreeBSD compatibility to easily
use the SDHC framework.  So in the future this might be an option.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.