Re: [PATCH 5/8] aspeed: Set eMMC 'boot-config' property to reflect HW strapping

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 5/7/24 07:38, Cédric Le Goater wrote:
> On 7/5/24 5:41 AM, Andrew Jeffery wrote:
>> On Thu, 2024-07-04 at 07:36 +0200, Cédric Le Goater wrote:
>>> From: Cédric Le Goater <clg@kaod.org>
>>>
>>> When the boot-from-eMMC HW strapping bit is set, use the 'boot-config'
>>> property to set the boot config register to boot from the first boot
>>> area partition of the eMMC device.
>>>
>>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>>> ---
>>>   hw/arm/aspeed.c | 15 +++++++++++----
>>>   1 file changed, 11 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c
>>> index 756deb91efd1..135f4eb72215 100644
>>> --- a/hw/arm/aspeed.c
>>> +++ b/hw/arm/aspeed.c
>>> @@ -327,7 +327,8 @@ void aspeed_board_init_flashes(AspeedSMCState *s, 
>>> const char *flashtype,
>>>       }
>>>   }
>>> -static void sdhci_attach_drive(SDHCIState *sdhci, DriveInfo *dinfo, 
>>> bool emmc)
>>> +static void sdhci_attach_drive(SDHCIState *sdhci, DriveInfo *dinfo, 
>>> bool emmc,
>>> +                               bool boot_emmc)
>>>   {
>>>           DeviceState *card;
>>> @@ -335,6 +336,9 @@ static void sdhci_attach_drive(SDHCIState *sdhci, 
>>> DriveInfo *dinfo, bool emmc)
>>>               return;
>>>           }
>>>           card = qdev_new(emmc ? TYPE_EMMC : TYPE_SD_CARD);
>>> +        if (emmc) {
>>> +            qdev_prop_set_uint8(card, "boot-config", boot_emmc ? 
>>> 0x48 : 0x0);
>>
>> 0x48 feels a little bit magic. I poked around a bit and there are some
>> boot-config macros, but not the ones you need and they're all in an
>> "internal" header anyway. I guess this is fine for now?
> 
> You are right and we should be using these :
> 
> hw/sd/sdmmc-internal.h:#define EXT_CSD_PART_CONFIG             179     
> /* R/W */

This field is R/W and expected to be configured by the guest.

Why the guest (u-boot) doesn't detect partitioning support?

See eMMC v4.5 section 7.4.60 PARTITIONING_SUPPORT [160] and earlier

   For e•MMC 4.5 Devices, Bit 2-0 in PARTITIONING_SUPPORT
   shall be set to 1.

We don't set it so far.

I see in u-boot mmc_startup_v4():

     /* store the partition info of emmc */
     mmc->part_support = ext_csd[EXT_CSD_PARTITIONING_SUPPORT];
     if ((ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & PART_SUPPORT) ||
         ext_csd[EXT_CSD_BOOT_MULT])
             mmc->part_config = ext_csd[EXT_CSD_PART_CONF];
     if (part_completed &&
         (ext_csd[EXT_CSD_PARTITIONING_SUPPORT] & ENHNCD_SUPPORT))
             mmc->part_attr = ext_csd[EXT_CSD_PARTITIONS_ATTRIBUTE];

I'm still waiting for the eMMC prerequisite to be reviewed
before looking at the eMMC patches in detail :/

Regards,

Phil.