The stock recovery is supposed to give you an on-screen menu.
I guess that it didn't do that?
This is supposed to show this menu:
Code:
Reboot system now
Reboot to bootloader
Apply update from ADB
Apply update from SD card
Wipe data/factory reset
Wipe cache partition
Mount /system
View recovery logs
Power off
This thing apparently has a dependency on the /vendor partition, but I'm not sure.