[Lenovo Vibe Z2 Pro Guides, News, & Discussion] user700512:
It may be better if steps 6 and 7 are removed from the instructions.

The device and its port are shown in the main QFIL dialog in place of "No Port Available".

Another important instruction would be appropriate to add - it is to switch to "Flat Build" in "Select Build Type".

With "Meta Build" selected by default, "Select Programmer" is inactive (greyed out).

I have K920_S288_160224_ROW on my piece of crap, and I have a Windows 10 x64 Home on the other side.

And I could not get QFIL to flash the boot loader unlocked.

After following the instructions here, I had QFIL start with:

Validating Application Configuration
Load APP Configuration
Load ARG Configuration
Validating Download Configuration
Image Search Path: C:\
Process Index:0
Programmer Path:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
Image Search Path: C:\UnlockBootloader_LP_ROW
Image Search Path: C:\UnlockBootloader_LP_ROW
RAWPROGRAM file path: C:\UnlockBootloader_LP_ROW\rawprogram0.xml
PATCH file path:C:\UnlockBootloader_LP_ROW\patch0.xml

After hitting <Download> while I was seeing my device and its port in QFIL, I either got:

Start Download
Program Path:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
Download Fail:Sahara Fail:QSaharaServer Fail:The directory name is invalid
Finish Download

or:

Start Download
Download Fail:Invalid physical address number
Finish Download

or:

Start Download
Download Fail:Value was either too large or too small for a UInt32.
Finish Download

I did have QFIL complete successfully, though, but…

After step 4:

4a. QFIL must be closed;

4b. QFIL must be started again;

4c. "Select Build Type" must be set to "Flat Build" again;

Then in step 5, holding all the time until the end <Vol. Up>, I got the following output.

But, I didn't get the phone auto-reboot (just powered off).

How do I check if it is unlocked?

Validating Application Configuration
Load APP Configuration
COM:-1
SAHARA:True
SAHARA:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
SEARCHPATH:C:\UnlockBootloader_LP_ROW
RAWPROGRAM:
rawprogram0.xml
PATCH:
patch0.xml
ACKRAWDATAEVERYNUMPACKETS:False
ACKRAWDATAEVERYNUMPACKETS:100
MAXPAYLOADSIZETOTARGETINBYTES:False
MAXPAYLOADSIZETOTARGETINBYTES:49152
DEVICETYPE:eMMC
PLATFORM:8x26
VALIDATIONMODE:0
RESETAFTERDOWNLOAD:False
MAXDIGESTTABLESIZE:8192
SWITCHTOFIREHOSETIMEOUT:30
RESETTIMEOUT:200
RESETDELAYTIME:2
FLATBUILDPATH:C:\
FLATBUILDFORCEOVERRIDE:True
QCNPATH:C:\Temp\00000000.qcn
QCNAUTOBACKUPRESTORE:False
SPCCODE:000000
ENABLEMULTISIM:False
Load ARG Configuration
Validating Download Configuration
Image Search Path: C:\UnlockBootloader_LP_ROW
RAWPROGRAM file path: C:\UnlockBootloader_LP_ROW\rawprogram0.xml
PATCH file path:C:\UnlockBootloader_LP_ROW\patch0.xml
Programmer Path:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
Process Index:0
Start Download
Program Path:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
Binary build date: May 13 2015 @ 14:41:37
QSAHARASERVER CALLED LIKE THIS: 'C:\Program Files (x86)\Qualcomm\QPST\bin\QSaharaServer.exe -p \\.\COM3 -s 13:C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn 'Current working dir: C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL
Sahara mappings:
2: amss.mbn
6: apps.mbn
8: dsp1.mbn
10: dbl.mbn
11: osbl.mbn
12: dsp2.mbn
16: efs1.mbn
17: efs2.mbn
20: efs3.mbn
21: sbl1.mbn
22: sbl2.mbn
23: rpm.mbn
25: tz.mbn
28: dsp3.mbn
29: acdb.mbn
30: wdt.mbn
31: mba.mbn
13: C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn
00:54:41: Requested ID 13, file: "C:\UnlockBootloader_LP_ROW\prog_emmc_firehose_8974.mbn"
00:54:41: 84192 bytes transferred in 0.015000 seconds (5.3528MBps)
00:54:41: File transferred successfully
NOTE: Target requested image 13 which is DeviceProgrammer. Forcing QUIT. This is by design, ** All is well ** SUCCESS!!
00:54:41: Sahara protocol completed
Sending Programmer Finished
Switch To FireHose
Wait for 3 seconds...
Max Payload Size to Target:49152 Bytes
Device Type:eMMC
Platform:8x26
Disable Ack Raw Data Every N Packets
Skip Write:False
Always Validate:False
Use Verbose:False
Binary build date: Jun 3 2015 @ 17:12:06
Build version: 15.06. 3.17.12.06
00:54:45: INFO: FH_LOADER WAS CALLED EXACTLY LIKE THIS
************************************************
C:\Program Files (x86)\Qualcomm\QPST\bin\fh_loader.exe --port=\\.\COM3 --sendxml=rawprogram0.xml --search_path=C:\UnlockBootloader_LP_ROW --noprompt --showpercentagecomplete --zlpawarehost=1 --memoryname=eMMC
************************************************
00:54:45: INFO: Current working dir (cwd): C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\
00:54:45: INFO: Showing network mappings to allow debugging
00:54:46: INFO:
00:54:46: INFO: Trying to store 'rawprogram0.xml' in string table
00:54:46: INFO: Looking for file 'rawprogram0.xml'
00:54:46: INFO: User wants to talk to port '\\.\COM3'
00:54:46: INFO: Took 0.00000000 seconds to open port
00:54:46: INFO: Sorting TAGS to ensure order is <configure>,<erase>, others, <patch>,<power>
00:54:46: INFO: If you don't want this, use --dontsorttags
00:54:46: INFO: Looking for file 'emmc_appsboot.mbn'
00:54:46: INFO: Looking for file 'gpt_main0.bin'
00:54:46: INFO: Looking for file 'gpt_backup0.bin'
00:54:46: INFO:
Total to be tansferd with <program> or <read> is 711.05 KB
00:54:46: INFO: Sending <configure>
00:54:46: INFO: TARGET SAID: 'Host's payload to target size is too large'
00:54:46: INFO: TARGET SAID: 'logbuf@0xF8023A78 fh@0xF80208E0'
00:54:46: INFO: fh.attrs.MaxPayloadSizeToTargetInBytes = 131072
00:54:46: INFO: fh.attrs.MaxPayloadSizeToTargetInBytesSupported = 131072
00:54:46: INFO: Target returned NAK for your <configure> but it does not seem to be an error. This is ok, fh_loader.exe attributes updated
00:54:46: INFO: In handleProgram('emmc_appsboot.mbn')
00:54:46: INFO: Looking for file 'emmc_appsboot.mbn'
00:54:46: INFO: =======================================================
00:54:46: INFO: {<program> FILE: 'C:\UnlockBootloader_LP_ROW\emmc_appsboot.mbn'}
00:54:46: INFO: {<program> (677.55 KB) 1356 sectors needed at location 264232 on LUN 0}
00:54:46: INFO: =======================================================
00:54:46: INFO: TARGET SAID: 'logbuf@0xF8023A78 fh@0xF80208E0'
00:54:46: INFO: TARGET SAID: 'start 264232, num 1356'
00:54:47: INFO: FILE ACCESS SLOW!! 678.00 KB in 0.015 seconds ( 44.14 MBps) --- Overall to target 0.125 seconds (5.30 MBps)
00:54:47: INFO: {percent files transferred 95.29%}
00:54:47: INFO: TARGET SAID: 'Finished sector address 265588'
00:54:47: INFO:
00:54:47: INFO: =======================================================
00:54:47: INFO: ==================== {SUCCESS} ========================
00:54:47: INFO: =======================================================
00:54:47: INFO: {percent files transferred 95.29%}
00:54:47: INFO: In handleProgram('gpt_main0.bin')
00:54:47: INFO: Looking for file 'gpt_main0.bin'
00:54:47: INFO: =======================================================
00:54:47: INFO: {<program> FILE: 'C:\UnlockBootloader_LP_ROW\gpt_main0.bin'}
00:54:47: INFO: {<program> (17.00 KB) 34 sectors needed at location 0 on LUN 0}
00:54:47: INFO: =======================================================
00:54:47: INFO: TARGET SAID: 'start 0, num 34'
00:54:47: INFO: FILE ACCESS SLOW!! 17.00 KB in 0.015 seconds ( 1.11 MBps) --- Overall to target 0.010 seconds (1.66 MBps)
00:54:47: INFO: {percent files transferred 97.68%}
00:54:47: INFO: TARGET SAID: 'Finished sector address 34'
00:54:47: INFO:
00:54:47: INFO: =======================================================
00:54:47: INFO: ==================== {SUCCESS} ========================
00:54:47: INFO: =======================================================
00:54:47: INFO: {percent files transferred 97.68%}
00:54:47: INFO: In handleProgram('gpt_backup0.bin')
00:54:47: INFO: Looking for file 'gpt_backup0.bin'
00:54:47: INFO: =======================================================
00:54:47: INFO: {<program> FILE: 'C:\UnlockBootloader_LP_ROW\gpt_backup0.bin'}
00:54:47: INFO: {<program> (16.50 KB) 33 sectors needed at location 0 on LUN 0}
00:54:47: INFO: =======================================================
00:54:47: INFO: TARGET SAID: 'start 61071327, num 33'
00:54:47: INFO: FILE ACCESS SLOW!! 16.50 KB in 0.015 seconds ( 1.07 MBps) --- Overall to target 0.010 seconds (1.61 MBps)
00:54:47: INFO: {percent files transferred 100.00%}
00:54:47: INFO: TARGET SAID: 'Finished sector address 61071360'
00:54:47: INFO:
00:54:47: INFO: =======================================================
00:54:47: INFO: ==================== {SUCCESS} ========================
00:54:47: INFO: =======================================================
00:54:47: INFO: {percent files transferred 100.00%}
00:54:47: INFO: ==============================================================
00:54:47: INFO: Files used and their paths
00:54:47: INFO: 1 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
00:54:47: INFO: 2 'C:\UnlockBootloader_LP_ROW\rawprogram0.xml'
00:54:47: INFO: 3 'C:\UnlockBootloader_LP_ROW\emmc_appsboot.mbn'
00:54:47: INFO: 4 'C:\UnlockBootloader_LP_ROW\gpt_main0.bin'
00:54:47: INFO: 5 'C:\UnlockBootloader_LP_ROW\gpt_backup0.bin'
00:54:47: INFO: _ (done)
00:54:47: INFO: | |
00:54:47: INFO: __| | ___ _ __ ___
00:54:47: INFO: / _` |/ _ \| '_ \ / _ \
00:54:47: INFO: | (_| | (_) | | | | __/
00:54:47: INFO: \__,_|\___/|_| |_|\___|
00:54:47: INFO: {All Finished Successfully}
00:54:47: INFO: FILE ACCESS SLOW!! 711.05 KB in 0.015 seconds ( 46.29 MBps) --- Overall to target 0.953 seconds (746.12 KBps)
00:54:47: INFO: {percent files transferred 100.00%}
Writing log to 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt', might take a minute
Log is 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
Binary build date: Jun 3 2015 @ 17:12:06
Build version: 15.06. 3.17.12.06
00:54:48: INFO: FH_LOADER WAS CALLED EXACTLY LIKE THIS
************************************************
C:\Program Files (x86)\Qualcomm\QPST\bin\fh_loader.exe --port=\\.\COM3 --sendxml=patch0.xml --search_path=C:\UnlockBootloader_LP_ROW --noprompt --showpercentagecomplete --zlpawarehost=1 --memoryname=eMMC
************************************************
00:54:48: INFO: Current working dir (cwd): C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\
00:54:48: INFO: Showing network mappings to allow debugging
00:54:48: INFO:
00:54:48: INFO: Trying to store 'patch0.xml' in string table
00:54:48: INFO: Looking for file 'patch0.xml'
00:54:48: INFO: User wants to talk to port '\\.\COM3'
00:54:48: INFO: Took 0.01600000 seconds to open port
00:54:48: INFO: Sorting TAGS to ensure order is <configure>,<erase>, others, <patch>,<power>
00:54:48: INFO: If you don't want this, use --dontsorttags
00:54:48: INFO: Sending <configure>
00:54:48: INFO: TARGET SAID: 'Host's payload to target size is too large'
00:54:48: INFO: TARGET SAID: 'logbuf@0xF8023A78 fh@0xF80208E0'
00:54:48: INFO: fh.attrs.MaxPayloadSizeToTargetInBytes = 131072
00:54:48: INFO: fh.attrs.MaxPayloadSizeToTargetInBytesSupported = 131072
00:54:48: INFO: Target returned NAK for your <configure> but it does not seem to be an error. This is ok, fh_loader.exe attributes updated
00:54:49: INFO: TARGET SAID: 'Patched sector 7 with 03A3DFDE'
00:54:49: INFO: TARGET SAID: 'Patched sector 61071332 with 03A3DFDE'
00:54:49: INFO: TARGET SAID: 'Patched sector 1 with 03A3DFDE'
00:54:49: INFO: TARGET SAID: 'Patched sector 61071359 with 03A3DFDE'
00:54:49: INFO: TARGET SAID: 'Patched sector 1 with 03A3DFFF'
00:54:49: INFO: TARGET SAID: 'Patched sector 61071359 with 03A3DFFF'
00:54:49: INFO: TARGET SAID: 'Patched sector 61071359 with 03A3DFDF'
00:54:49: INFO: TARGET SAID: 'crc start sector 2, over bytes 3072'
00:54:49: INFO: TARGET SAID: 'Patched sector 1 with B5BEDE61'
00:54:49: INFO: TARGET SAID: 'crc start sector 61071327, over bytes 3072'
00:54:49: INFO: TARGET SAID: 'Patched sector 61071359 with B5BEDE61'
00:54:49: INFO: TARGET SAID: 'Patched sector 1 with 00000000'
00:54:50: INFO: TARGET SAID: 'crc start sector 1, over bytes 92'
00:54:50: INFO: TARGET SAID: 'Patched sector 1 with 1125B526'
00:54:50: INFO: TARGET SAID: 'Patched sector 61071359 with 00000000'
00:54:50: INFO: TARGET SAID: 'crc start sector 61071359, over bytes 92'
00:54:50: INFO: TARGET SAID: 'Patched sector 61071359 with AD0AE52E'
00:54:50: INFO: ==============================================================
00:54:50: INFO: Files used and their paths
00:54:50: INFO: 1 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
00:54:50: INFO: 2 'C:\UnlockBootloader_LP_ROW\patch0.xml'
00:54:50: INFO: _ (done)
00:54:50: INFO: | |
00:54:50: INFO: __| | ___ _ __ ___
00:54:50: INFO: / _` |/ _ \| '_ \ / _ \
00:54:50: INFO: | (_| | (_) | | | | __/
00:54:50: INFO: \__,_|\___/|_| |_|\___|
00:54:50: INFO: {All Finished Successfully}
00:54:50: INFO: FILE ACCESS SLOW!! 0.00 B in 0.015 seconds ( 0.00 Bps) --- Overall to target 1.438 seconds (0.00 Bps)
Writing log to 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt', might take a minute
Log is 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
Binary build date: Jun 3 2015 @ 17:12:06
Build version: 15.06. 3.17.12.06
00:54:51: INFO: FH_LOADER WAS CALLED EXACTLY LIKE THIS
************************************************
C:\Program Files (x86)\Qualcomm\QPST\bin\fh_loader.exe --port=\\.\COM3 --noprompt --showpercentagecomplete --zlpawarehost=1 --memoryname=eMMC --setactivepartition=0
************************************************
00:54:51: INFO: Current working dir (cwd): C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\
00:54:51: INFO: Showing network mappings to allow debugging
00:54:51: INFO: User wants to talk to port '\\.\COM3'
00:54:51: INFO: Took 0.00000000 seconds to open port
00:54:51: INFO: Sorting TAGS to ensure order is <configure>,<erase>, others, <patch>,<power>
00:54:51: INFO: If you don't want this, use --dontsorttags
00:54:51: INFO: Sending <configure>
00:54:51: INFO: TARGET SAID: 'Host's payload to target size is too large'
00:54:51: INFO: TARGET SAID: 'logbuf@0xF8023A78 fh@0xF80208E0'
00:54:51: INFO: fh.attrs.MaxPayloadSizeToTargetInBytes = 131072
00:54:51: INFO: fh.attrs.MaxPayloadSizeToTargetInBytesSupported = 131072
00:54:51: INFO: Target returned NAK for your <configure> but it does not seem to be an error. This is ok, fh_loader.exe attributes updated
00:54:51: INFO: Sending <setbootablestoragedrive>
00:54:51: INFO: TARGET SAID: 'Set bootable drive to 0.'
00:54:51: INFO: ==============================================================
00:54:51: INFO: Files used and their paths
00:54:51: INFO: 1 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
00:54:51: INFO: _ (done)
00:54:51: INFO: | |
00:54:51: INFO: __| | ___ _ __ ___
00:54:51: INFO: / _` |/ _ \| '_ \ / _ \
00:54:51: INFO: | (_| | (_) | | | | __/
00:54:51: INFO: \__,_|\___/|_| |_|\___|
00:54:51: INFO: {All Finished Successfully}
00:54:51: INFO: FILE ACCESS SLOW!! 0.00 B in 0.015 seconds ( 0.00 Bps) --- Overall to target 0.203 seconds (0.00 Bps)
Writing log to 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt', might take a minute
Log is 'C:\Users\User Account\AppData\Roaming\Qualcomm\QFIL\port_trace.txt'
Download Succeed
Finish Download