[PATCH v3] mmc: allow use of hardware partition names for mmc partconf

[Tim Harvey]

On Mon, Apr 29, 2024 at 1:51 PM Marek Vasut <marex at denx.de> wrote:
>
> On 4/29/24 6:48 PM, Tim Harvey wrote:
> > On Sat, Apr 27, 2024 at 4:20 PM Marek Vasut <marex at denx.de> wrote:
> >>
> >> On 4/27/24 2:11 AM, Tim Harvey wrote:
> >>
> >> [...]
> >>
> >>> diff --git a/include/mmc.h b/include/mmc.h
> >>> index 4b8327f1f93b..7243bd761202 100644
> >>> --- a/include/mmc.h
> >>> +++ b/include/mmc.h
> >>> @@ -381,6 +381,21 @@ enum mmc_voltage {
> >>>    #define MMC_TIMING_MMC_HS200        9
> >>>    #define MMC_TIMING_MMC_HS400        10
> >>>
> >>> +/* emmc hardware partition values */
> >>> +enum emmc_hwpart {
> >>> +     EMMC_HWPART_DEFAULT = 0,
> >>
> >> One more thing ... eMMC hardware partition 0 and 7 are both referring to
> >> USER HW partition. Have a look at the git log, there have been patches
> >> which handled this case in the MMC subsystem from about a year ago.
> >
> > Hi Marek,
> >
> > I can't find what you are referring to. I assume you are talking about
> > calling the first name something other than 'user' as technically it's
> > not (but it gets treated as user).
> >
> > Can you find the commit or discussion you are thinking about?
>
> It seems this whole thing is much older:
>
> 7dbe63bc950b ("SPL: Add CONFIG_SUPPORT_EMMC_BOOT support to
> CONFIG_SPL_FRAMEWORK")
>
> +                * We need to check what the partition is configured to.
> +                * 1 and 2 match up to boot0 / boot1 and 7 is user data
> +                * which is the first physical partition (0).
> +                */
> +               int part = (mmc->part_config >> 3) & PART_ACCESS_MASK;
> +
> +               if (part == 7)
> +                       part = 0;

Hi Marek,

Sorry, I haven't been able to work on U-Boot for the past week or so
and am just getting back to this.

I'm glad you pointed this out as it made me aware that there is a bit
of a mixing of eMMC PARTITION_CONFIG (Ext CSD 179) fields
BOOT_PARTITION_ENABLE and PARTITION_ACCESS in U-Boot currently.

I'm going to add an enumerated type for each and update the various
places where a 'conversion' as above is done but I'm still a bit torn
on naming conventions.

Consider the following:
- the eMMC spec refers to boot partitions and gp partitions as 1 based
- the Linux kernel device names for these are 0 based
- U-Boot does not currently refer to the boot devices by names but
does currently refer to the gp's by names using 1-based names (the
'mmc hwpartition' command)

Personally I would like to name the boot partitions 'boot0' and
'boot1' to match Linux but I think I should name the gp's
'gp1'...'gp4' to be backward compatible with the 'mmc hwpartition'
command.

What do you think?

Best Regards,

Tim