On 03/11/2020 18:36, Atish Patra wrote:
On Tue, Nov 3, 2020 at 10:28 AM Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> wrote:
On 03/11/2020 18:10, Cyril.Jean@xxxxxxxxxxxxx wrote:
On 11/3/20 3:07 PM, Atish Patra wrote:
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On Fri, Oct 30, 2020 at 2:20 PM Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> wrote:
,snip[
@Cyril : Can we enable both eMMC & sdcard at the same time ?
I would put /both/ in but only enable the one in use for the moment.
Our boards are booting of eMMC as supplied, so this isn't going to work
as well. The eMMC is 8bit wide, and thus is only delivering 11MB/sec
instead of 22MB/sec. This performance is still not great, but losing
half the data-rate is just not good.
I am not sure what should be enabled by default. Updating sdcard is much
easier than eMMC card and we use that approach.
@Cyril: Is there a way that we can enable both ?
Yes, we can enable both but this requires a modification to the FPGA
design. One of the guys prototyped this while I was away. We will move
this along. This will require reprogramming the FPGA with a new design
and HSS version.
Regards,
Cyril.
I either missed or couldn't find a way of forcing the boot mode to be
from the SD slot. Have I missed something? At the moment we'd like to
have more storage available as the ~7G free on the eMMC is not enough.
I use tftpboot to load the kernel & DT from the network. SD card is
enabled in this DT and Linux
kernel uses SD slot instead of eMMC.
To summarize, eMMC is used for HSS & U-Boot while SD card is used for
Linux which makes
more storage available to Linux.
IMO, we should enable the sdcard for Linux DT until updated FPGA
design & HSS is available.
Interesting as for me the default is for Linux to use the eMMC as
well. I can't see any way for forcing the selection lines in the
DT to say eMMC vs SD.
If there is a way of controlling the selection lines then it might
be possible to have both cards enabled with a bus selection MUX in
software.
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
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