mate 10 successfully to downgrade from EMUI 9 to 8
 

mate 10 successfully to downgrade from EMUI 9 to 8

Looking for a device in upgrade mode
COM8: Android Adapter PCUI (COM8)
COM9: DBAdapter Reserved Interface (COM9)

4/9/2019 6:14:55 PM Starting to write device in UPGRADE mode...
File to update: UPDATE.APP
Current version: ALP_Global_xloader
Validating file...
Looking for attached port...
Preparing to write...
Writing file 1 of 43: SHA256RSA...OK
Writing file 2 of 43: CRC...OK
Writing file 3 of 43: CURVER...OK
Writing file 4 of 43: VERLIST...OK
Writing file 5 of 43: PACKAGE_TYPE...OK
Writing file 6 of 43: HISIUFS_GPT...OK
Writing file 7 of 43: XLOADER...OK
Writing file 8 of 43: FW_LPM3...OK
Writing file 9 of 43: HHEE...OK
Writing file 10 of 43: FASTBOOT...OK
Writing file 11 of 43: VECTOR...OK
Writing file 12 of 43: VBMETA...OK
Writing file 13 of 43: MODEMNVM_UPDATE...OK
Writing file 14 of 43: MODEMNVM_CUST...OK
Writing file 15 of 43: TEEOS...OK
Writing file 16 of 43: TRUSTFIRMWARE...OK
Writing file 17 of 43: SENSORHUB...OK
Writing file 18 of 43: FW_HIFI...OK
Writing file 19 of 43: KERNEL...OK
Writing file 20 of 43: RAMDISK...OK
Writing file 21 of 43: RECOVERY_RAMDISK...OK
Writing file 22 of 43: RECOVERY_VENDOR...OK
Writing file 23 of 43: RECOVERY_VBMETA...OK
Writing file 24 of 43: ERECOVERY_KERNEL...OK
Writing file 25 of 43: ERECOVERY_RAMDISK...OK
Writing file 26 of 43: ERECOVERY_VENDOR...OK
Writing file 27 of 43: ERECOVERY_VBMETA...OK
Writing file 28 of 43: HDCP...OK
Writing file 29 of 43: DTS...OK
Writing file 30 of 43: DTO...OK
Writing file 31 of 43: CACHE...OK
Writing file 32 of 43: SYSTEM...OK
Writing file 33 of 43: CUST...OK
Writing file 34 of 43: ISP_FIRMWARE...OK
Writing file 35 of 43: MODEM_FW...OK
Writing file 36 of 43: HISEE_IMG...OK
Writing file 37 of 43: HISEE_FS...OK
Writing file 38 of 43: VENDOR...OK
Writing file 39 of 43: VERSION...OK
Writing file 40 of 43: ODM...OK
Writing file 41 of 43: PRODUCT...OK
Writing file 42 of 43: USERDATA...OK
Writing file 43 of 43: UFSFW...OK
Software written

4/9/2019 6:34:49 PM Starting to write device in UPGRADE mode...
File to update: update_ALP-L09_hw_eu.app
Current version: ALP_Global_xloader
Validating file...
Looking for attached port...
Preparing to write...
Writing file 1 of 9: SHA256RSA...OK
Writing file 2 of 9: CRC...OK
Writing file 3 of 9: CURVER...OK
Writing file 4 of 9: VERLIST...OK
Writing file 5 of 9: PACKAGE_TYPE...OK
Writing file 6 of 9: HISIUFS_GPT...OK
Writing file 7 of 9: CUST...OK
Writing file 8 of 9: VERSION...OK
Writing file 9 of 9: USERDATA...
Writing file 9 of 9: USERDATA...OK
Software written
4/9/2019 6:41:30 PM Writing device finished OK

would you please share us how do that, is it need root or unlock bootloader and also is you use whole update.app parts or you us selective parts from update.app.............thanks