Hi,
I have this issu, when i boot the dragonboard-410c, the emmc is registred as mmc1 not default one ( mmc0).
[ 1.352732] VFIO - User Level meta-driver version: 0.3
[ 1.361604] ehci_hcd: USB 2.0 ‘Enhanced’ Host Controller (EHCI) driver
[ 1.363410] ehci-pci: EHCI PCI platform driver
[ 1.369958] ehci-platform: EHCI generic platform driver
[ 1.374540] ehci-orion: EHCI orion driver
[ 1.379621] ehci-exynos: EHCI Exynos driver
[ 1.383761] ohci_hcd: USB 1.1 ‘Open’ Host Controller (OHCI) driver
[ 1.387636] ohci-pci: OHCI PCI platform driver
[ 1.393911] ohci-platform: OHCI generic platform driver
[ 1.398473] ohci-exynos: OHCI Exynos driver
[ 1.403611] usbcore: registered new interface driver usb-storage
[ 1.407679] usbcore: registered new interface driver usbserial_generic
[ 1.413862] usbserial: USB Serial support registered for generic
[ 1.424173] i2c /dev entries driver
[ 1.427903] i2c_qup 78b7000.i2c: using default clock-frequency 100000
[ 1.429566] i2c_qup 78b7000.i2c:
[ 1.429566] tx channel not available
[ 1.436863] at24 3-0050: supply vcc not found, using dummy regulator
[ 1.471599] i2c_qup 78b8000.i2c: using default clock-frequency 100000
[ 1.471633] i2c_qup 78b8000.i2c:
[ 1.471633] tx channel not available
[ 1.478208] i2c_qup 78ba000.i2c: using default clock-frequency 100000
[ 1.483815] i2c_qup 78ba000.i2c:
[ 1.483815] tx channel not available
[ 1.495400] rtc-s35390a 0-0030: registered as rtc0
[ 1.498132] rtc-s35390a 0-0030: setting system clock to 2021-12-06T11:22:39 UTC (1638789759)
[ 1.502315] at24 0-0050: supply vcc not found, using dummy regulator
[ 1.511400] at24 0-0050: 32768 byte 24c256 EEPROM, writable, 1 bytes/write
[ 1.527867] sdhci: Secure Digital Host Controller Interface driver
[ 1.527900] sdhci: Copyright(c) Pierre Ossman
[ 1.533880] Synopsys Designware Multimedia Card Interface driver
[ 1.539048] sdhci-pltfm: SDHCI platform and OF driver helper
[ 1.546623] ledtrig-cpu: registered to indicate activity on CPUs
[ 1.550801] usbcore: registered new interface driver usbhid
[ 1.555098] usbhid: USB HID core driver
[ 1.562971] genirq: irq_chip msmgpio did not update eff. affinity mask of irq 68
[ 1.570764] usbcore: registered new interface driver snd-usb-audio
[ 1.573790] NET: Registered protocol family 10
[ 1.579784] Segment Routing with IPv6
[ 1.582338] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[ 1.586553] NET: Registered protocol family 17
[ 1.591896] 9pnet: Installing 9P2000 support
[ 1.596285] Key type dns_resolver registered
[ 1.601776] registered taskstats version 1
[ 1.604900] Loading compiled-in X.509 certificates
[ 1.643579] s1: supplied by regulator-dummy
[ 1.643834] s2: supplied by regulator-dummy
[ 1.646676] s3: Bringing 0uV into 375000-375000uV
[ 1.650923] s3: supplied by regulator-dummy
[ 1.655683] s4: Bringing 0uV into 1800000-1800000uV
[ 1.657807] usb3503 usb2517: switched to HUB mode
[ 1.659626] s4: supplied by regulator-dummy
[ 1.664472] usb3503 usb2517: usb3503_probe: probed in hub mode
[ 1.669706] l1: Bringing 0uV into 375000-375000uV
[ 1.679396] l1: supplied by s3
[ 1.684076] l2: Bringing 0uV into 1200000-1200000uV
[ 1.687086] l2: supplied by s3
[ 1.692037] l3: supplied by s3
[ 1.694943] l4: Bringing 0uV into 1750000-1750000uV
[ 1.698112] l4: supplied by s4
[ 1.701113] sdhci_msm 7864900.sdhci: Got CD GPIO
[ 1.702786] l5: Bringing 0uV into 1750000-1750000uV
[ 1.705817] sdhci_msm 7864900.sdhci: Got WP GPIO
[ 1.706488] input: gpio-keys as /devices/platform/gpio-keys/input/input0
[ 1.707403] ALSA device list:
[ 1.707413] No soundcards found.
[ 1.710757] l5: supplied by s4
[ 1.729561] sdhci_msm 7864900.sdhci: Got CD GPIO
[ 1.732942] l6: Bringing 0uV into 1800000-1800000uV
[ 1.735932] sdhci_msm 7864900.sdhci: Got WP GPIO
[ 1.740815] l6: supplied by s4
[ 1.750236] l7: Bringing 0uV into 1750000-1750000uV
[ 1.753306] l7: supplied by s4
[ 1.757876] l8: Bringing 0uV into 1750000-1750000uV
[ 1.761181] l8: supplied by regulator-dummy
[ 1.762891] sdhci_msm 7864900.sdhci: Got CD GPIO
[ 1.765777] l9: Bringing 0uV into 1750000-1750000uV
[ 1.769870] sdhci_msm 7864900.sdhci: Got WP GPIO
[ 1.774869] l9: supplied by regulator-dummy
[ 1.784250] l10: Bringing 0uV into 1750000-1750000uV
[ 1.788227] l10: supplied by regulator-dummy
[ 1.793350] rpm_reg_probe: do not handle l11!
[ 1.797496] mmc1: SDHCI controller on 7824900.sdhci [7824900.sdhci] using ADMA 64-bit
[ 1.797574] l12: Bringing 0uV into 1750000-1750000uV
[ 1.807177] sdhci_msm 7864900.sdhci: Got CD GPIO
[ 1.809796] l12: supplied by regulator-dummy
[ 1.814752] sdhci_msm 7864900.sdhci: Got WP GPIO
[ 1.819323] l13: Bringing 0uV into 1750000-1750000uV
[ 1.828264] l13: supplied by regulator-dummy
[ 1.833119] l14: Bringing 0uV into 1750000-1750000uV
[ 1.837462] l14: supplied by regulator-dummy
[ 1.842336] l15: Bringing 0uV into 1750000-1750000uV
[ 1.846531] l15: supplied by regulator-dummy
[ 1.852263] l16: Bringing 0uV into 1750000-1750000uV
[ 1.853807] mmc0: SDHCI controller on 7864900.sdhci [7864900.sdhci] using ADMA 64-bit
[ 1.855864] l16: supplied by regulator-dummy
[ 1.868457] l17: Bringing 0uV into 3300000-3300000uV
[ 1.872876] l17: supplied by regulator-dummy
[ 1.877769] l18: Bringing 0uV into 1750000-175000�[ 1.887469] Waiting for root device /dev/mmcblk0p14…
[ 1.970402] mmc1: Card appears overclocked; req 177770000 Hz, actual 177777777 Hz
[ 1.970486] mmc1: Card appears overclocked; req 177770000 Hz, actual 177777777 Hz
[ 1.980347] mmc1: new HS200 MMC card at address 0001
[ 1.985716] mmcblk1: mmc1:0001 Q2J55L 7.13 GiB
[ 1.989644] mmcblk1boot0: mmc1:0001 Q2J55L 2.00 MiB
[ 1.993935] mmcblk1boot1: mmc1:0001 Q2J55L 2.00 MiB
[ 1.999026] mmcblk1rpmb: mmc1:0001 Q2J55L 4.00 MiB, chardev (234:0)
[ 2.005762] mmcblk1: p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 p11 p12 p13 p14
[ 2.701379] random: fast init done
[ 74.373635] random: crng init done
thanks