On Tue, Nov 3, 2020 at 10:39 AM Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> wrote: > > 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: > >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > >>>> > >>>> 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. > because you are probably loading the DT passed by U-boot. I load the DTB built from the Linux source (the one present in this patch) by stopping the autoboot in U-Boot. The DT in U-Boot disables the SD card. > 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 > > https://www.codethink.co.uk/privacy.html -- Regards, Atish
