The Lenovo Vibe P1 Firmware package shared in this post is based on Android M (Marshmallow, 6.0.1).
Brief firmware info:
Device: Lenovo Vibe P1
Firmware Build: P1a42_S288_160712_ROW
Size: 1.79 GB
File Name: P1a42_S288_160721_ROW_RAW_QFIL.rar
Downloads / Flashing Instructions
Lenovo Vibe P1 stock ROM – Download
How to flash
To learn how to flash this firmware on your device, click here.