[Huawei P10 ROMs, Kernels, Recoveries, & Other Deve] Neo Wong:
I managed to use the 3.1.0 to mount the partition manually.

List the partition.

Disk /dev/block/mmcblk0: 122142720 sectors, 2296M

Logical sector size: 512

Disk identifier (GUID): f9f21fff-a8d4-5f0e-9746-594869aec34e

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 122142719

Number Start (sector) End (sector) Size Code Name

1 1024 2047 512K 0700 frp

2 2048 6143 2048K 0700 persist

3 6144 16383 5120K 0700 reserved1

4 16384 17407 512K 0700 reserved6

5 17408 18431 512K 0700 vrl

6 18432 19455 512K 0700 vrl_backup

7 19456 36863 8704K 0700 modem_secure

8 36864 49151 6144K 0700 nvme

9 49152 180223 64.0M 0700 oeminfo

10 180224 245759 32.0M 0700 secure_storage

11 245760 311295 32.0M 0700 modem_om

12 311296 319487 4096K 0700 modemnvm_factory

13 319488 327679 4096K 0700 modemnvm_backup

14 327680 352255 12.0M 0700 modemnvm_img

15 352256 360447 4096K 0700 modemnvm_system

16 360448 524287 80.0M 0700 splash2

17 524288 1048575 256M 0700 cache

18 1048576 1052671 2048K 0700 bootfail_info

19 1052672 1056767 2048K 0700 misc

20 1056768 1122303 32.0M 0700 reserved2

21 1122304 1130495 4096K 0700 reserved10

22 1130496 1146879 8192K 0700 hisee_fs

23 1146880 1179647 16.0M 0700 dfx

24 1179648 1212415 16.0M 0700 rrecord

25 1212416 1212927 256K 0700 fw_lpm3_a

26 1212928 1220607 3840K 0700 reserved3_a

27 1220608 1228799 4096K 0700 hisee_img_a

28 1228800 1253375 12.0M 0700 fastboot_a

29 1253376 1261567 4096K 0700 vector_a

30 1261568 1265663 2048K 0700 isp_boot_a

31 1265664 1294335 14.0M 0700 isp_firmware_a

32 1294336 1318911 12.0M 0700 fw_hifi_a

33 1318912 1335295 8192K 0700 teeos_a

34 1335296 1466367 64.0M 0700 recovery2_a

35 1466368 1499135 16.0M 0700 sensorhub_a

36 1499136 1564671 32.0M 0700 boot_a

37 1564672 1695743 64.0M 0700 recovery_a

38 1695744 1728511 16.0M 0700 dts_a

39 1728512 1732607 2048K 0700 trustfirmware_a

40 1732608 1847295 56.0M 0700 modem_fw_a

41 1847296 1949695 50.0M 0700 reserved4_a

42 1949696 2113535 80.0M 0700 modemnvm_update_a

43 2113536 2179071 32.0M 0700 patch_a

44 2179072 2244607 32.0M 0700 version_a

45 2244608 3850239 784M 0700 vendor_a

46 3850240 4243455 192M 0700 product_a

47 4243456 4636671 192M 0700 cust_a

48 4636672 11911167 3552M 0700 system_a

49 11911168 12173311 128M 0700 reserved5

50 12173312 122142719 52.4G 0700 userdata

And also the mount point.

/dev/block/platform # blkid

/dev/block/mmcblk1p1: UUID="E4B4-6465" TYPE="exfat"

/dev/block/mmcblk0p50: UUID="1f33733d-2667-411c-a600-89c252f86811" TYPE="f2fs"

/dev/block/mmcblk0p48: LABEL="system" UUID="da594c53-9beb-f85c-85c5-cedf76546f7a" TYPE="ext4"

/dev/block/mmcblk0p47: LABEL="cust" UUID="f00b9a3b-4d08-c450-8c71-e78719096954" TYPE="ext4"

/dev/block/mmcblk0p46: LABEL="product" UUID="27c5486f-1eff-4f5c-a8cd-e7b0e760d4a5" TYPE="ext4"

/dev/block/mmcblk0p45: LABEL="vendor" UUID="6d16bab1-58d9-3c5d-8f14-f608f924affd" TYPE="ext4"

/dev/block/mmcblk0p44: LABEL="version" UUID="d8003b02-a900-9650-8909-c6d9835f2dd9" TYPE="ext4"

/dev/block/mmcblk0p40: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p22: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p17: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p16: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p14: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p11: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p10: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

/dev/block/mmcblk0p7: UUID="57f8f4bc-abf4-655f-bf67-946fc0f9f25b" TYPE="ext4"

So we'll know the mount point, one partition not list here is cache, from the two above list, we can guess it's 17.

run below command on windows (USB connected) after booted to TWRP, if there's only need for rebrand, only mount cache is good enough.

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p48 /system"

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p47 /cust"

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p45 /vendor"

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p46 /product"

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p44 /version"

adb shell "mount -o rw -t ext4 /dev/block/mmcblk0p17 /cache"

I have use this method successfully rebrand my VTR-AL00 to VTR-L29C. just change something on the script as the oeminfo and recovery/recovery2 are using different block.

Line 288:

$ADB shell "dd if=/tmp/oeminfo.bin of=/dev/block/mmcblk0p9 bs=1048576"

Line 318,319

$ADB shell "dd if=$RECOVERY_TMP of=/dev/block/mmcblk0p37 bs=1048576"

$ADB shell "dd if=$RECOVERY2_TMP of=/dev/block/mmcblk0p34 bs=1048576"