not sure if you can set partconf with mmc-utils, but 0x1 imho is wrong…afair it should be 0x48, but if emmc boots till uboot…mhm, but it does not look like mine…
try booting in uboot from sdcard and run the mmc partconf
please post full output…it looks like emmc was preflashed, but it should be blank on userparttion after you created the filesystem on mmcblk0 directly without partition.
you need at least boot till uboot from emmc and if uboot itself can read sata drive you can boot from it (afair on r64 uboot was able to access sata).
tried to flash from uboot alone:
check order of mmc devices, start and list usb content
BPI-R64> mmc list
mmc@11230000: 0 (eMMC)
mmc@11240000: 1
BPI-R64> usb start
starting USB...
Bus usb@1a0c0000: xhci-mtk usb@1a0c0000: hcd: 0x000000001a0c0000, ippc: 0x000000
xhci-mtk usb@1a0c0000: ports disabled mask: u3p-0x0, u2p-0x0
xhci-mtk usb@1a0c0000: u2p:2, u3p:1
Register 300010f NbrPorts 3
Starting the controller
USB XHCI 0.96
scanning bus usb@1a0c0000 for devices... 2 USB Device(s) found
scanning usb for storage devices... 1 Storage Device(s) found
BPI-R64>
BPI-R64> ls usb 0:1 r64
./
../
512 r64_header_emmc.bin
65597 bpi-r64_emmc_bl2.img
988948 bpi-r64_emmc_fip.bin
3 file(s), 2 dir(s)
switch to boot0 block and write bl2
BPI-R64> mmc partconf 0 1 1 1
BPI-R64> fatload usb 0:1 $loadaddr r64/bpi-r64_emmc_bl2.img
ERROR: reserving fdt memory region failed (addr=0 size=43000000 flags=4)
65597 bytes read in 16 ms (3.9 MiB/s)
BPI-R64> printenv loadaddr
loadaddr=0x44000000
BPI-R64> mmc write ${loadaddr} 0x0 0x400
MMC write: dev # 0, block # 0, count 1024 ... 1024 blocks written: OK
switch to userpart and flash first emmc-header
BPI-R64> mmc partconf 0 1 1 0
BPI-R64> fatload usb 0:1 $loadaddr r64/r64_header_emmc.bin
ERROR: reserving fdt memory region failed (addr=0 size=43000000 flags=4)
512 bytes read in 10 ms (49.8 KiB/s)
BPI-R64> mmc write ${loadaddr} 0x0 0x400
MMC write: dev # 0, block # 0, count 1024 ... 1024 blocks written: OK
load and write fip (uboot)
BPI-R64> fatload usb 0:1 $loadaddr r64/bpi-r64_emmc_fip.bin
ERROR: reserving fdt memory region failed (addr=0 size=43000000 flags=4)
988948 bytes read in 92 ms (10.3 MiB/s)
BPI-R64> mmc write ${loadaddr} 0x800 ${filesize}
MMC write: dev # 0, block # 2048, count 988948 ... 988948 blocks written: OK
BPI-R64>
bl2 boots up but seems i need fip-partition (so i have to flash image first)
BPI-R64>
F0: 102B 0000
F5: 480A 0031
F5: 480A 0031
F3: 0000 0000
V0: 0000 0000 [0001]
00: 0000 0000
BP: 0400 0041 [0000]
G0: 1190 0000
T0: 0000 02E7 [000F]
Jump to BL
NOTICE: BL2: v2.9(release):44cbe55c6 emmc
NOTICE: BL2: Built : 09:10:57, Feb 1 2024
NOTICE: WDT: Cold boot
NOTICE: WDT: disabled
NOTICE: CPU: MT7622
ERROR: Partition 'fip' not found
ERROR: FIP boot source initialization failed with -2
PANIC at PC : 0x0000000000205318
i try to include emmc in r64 createimg…to not need flash sdmmc first and replace header and fip…so i can test the created image directly 
pipeline is running…
i put in to the root