[ONE General] Das.Flaigsi:
This guid shows two things:

1. How to enable QPST and USB diag mode.

2. How to enable rSAP.

For this guid your device have to be rooted.

In the newer versions of OnePlus' CyanogenMod diag mode is disabled in kernal. Therefore you have to flash an earlier ROM. In this step download Calkulin's Stock Rooted XNPH44S ROM and store zip to your device.

Go to recovery and make a full backup. This is really necessary to preserve the state of your phone.

Wipe Dalvik Cache, System, Data and Cache. ATTENSION: This will delete all your settings, apps and app data!

Install XNPH44S ROM

After rebooting system go to Settings -> About Device -> tab ten times on Build-Number to unlock developer settings. Than go to Developer settings and make sure USB debugging is enabled.

Download the package, containing driver and QPST

Connect your device to USB, go to Settings -> Storage -> USB computer connection and deselect both MTP and PTP.

For Win8 and Win10: restart with deactivated driver signature check.

Open ADB (Android SDK) and type following commands:

adb shell

su

setprop sys.usb.config diag,adb

Go to Windows Device Manager and open Other Devices node. There are two entries of our device "A0001". Klick right on the first one and choose Update driver software -> Browse my computer... -> Let me pick from a list... -> Show all devices -> Have disk -> Browse...

Browse to folder Driver in downloaded package, than open Win x64 or Win x86 corresponding to your system, select *.inf file and apply.

After seccessful installation there is a Modems node in Device Manager, containing node HTC USB Modem. Right click and go to Properties. In top of the Modem tab page is the information about used COM-port. Remember that COM<number>.

Go to QPST folder in downloaded package and execute setup.exe to install QPST.

Open QPST Configuration from windows Start menu, go to Ports tab page and click on Add New Port.... Type (the remembered) COM<number> to the "Port:" text box and OPO to the "Port Label:" text box. Than click on OK.

Active Phones tab page should now look like this:

Now you can use QPST.

Open EFS Explorer from windows Start menu. It may take a moment to read data from your device.

On left side you can see a folder tree like in file explorer. Navigate to /nv/item_files/modem/qmi/uim

Click right on right side and than Copy Item File from PC. Browse to EFS Entry folder of downloaded package and choose file sap_security_restrictions.

Close all windows and reboot your device. If you want, you can repeat the steps 10, 16 and 17 to verify success.

Boot to recovery and restore your backup.

Now go to Google Play and download app Bluetooth SIM Access Install and app Bluetooth SIM Access (Trial)

Open Install app and click on Install system files. The phone have to reboot after installation. If you want to verify successful installation, open app again, the desintall button have to be enabled now.

Enable your Bluetooth

Open Bluetooth SIM Access (Trial) app go to Settings -> Check SIM Access. If there no errors and several entries with green check marks, than rSAP is working now.

Files:

Package (On Mega click on 'download in browser')

ROM (On Mega click on 'download in browser')

Acknowledgement:

Thank you devilsshadow, for your tutorial, which showed me how to setup QPST.

Thank you Calkulin, for your ROM, which makes it possible to use QPST.

Special thanks goes to Martin , for developing his great apps and making our phones better.