H3resc is a specialized rescue menu built for H3Droid which can be reached by booting your H3Droid device into rescue mode.
Rescue mode can be accomplished by pressing 'space bar' in uboot on Allwinner H3 Devices during the boot process.
You will see U-boot announce it is booting into H3resc and then you will be greeted by the above menu.
11 - Spawn shell - Spawns a sh shell with busybox providing access to the boot partition on the card
21 - Switch uboot - Allows you to choose the uboot for your board - just like during installation.
22 - Switch fex - Allows you to choose the fex for your board - just like during installation.
23 - Change display resolution - Allows you to set display resolution so it is retained each boot
24 - Edit fex - advanced feature - Allows you to edit the fex file you currently have in use to make adjustments
(Change settings such as 'DRAM' or advanced display settings)
25 - Edit boot cmd - advanced feature - Allows you to edit the boot.cmd which is used to tell uboot how to start the system
26 - Edit ssh authorized keys - Allows you to add SSH key to H3Droid
27 - Generate ssh key - Allows you to generate an SSH key pair
31 - Enable wifi - Enable WiFi network in H3resc
33 - Check for updates - If you have ethernet plugged in and an internet connection this will check our servers for any new updates to H3Droid
34 - Update from USB drive - This allows you to upgrade H3Droid from a USB drive with the latest release package on it
(offers the ability to upgrade without losing your apps and settings)
51 - Clean data partition - Does just what it sounds like, wipes all user data from Android (accounts, settings, etc)
53 - Toggle Gapps updates - Enables / Disables Google Play Service updates in H3Droid
55 - Resize data patition - Allows you to resize the H3Droid data patition
56 - Clone sd to emmc - Clone the SDcard you are currently booting from to the eMMc on your device
57 - Add Armbian - Install Armbian onto currently booted device (creates a 4th partition and installs Armbian there)
97 - Reboot to Armbian - Next reboot, reboot the system into Armbian automatically (without pressing 'a')
98 - Reboot to h3resc - Next reboot, reboot the system into H3Resc automatically (without pressing 'space bar')
99 - Reboot to h3droid - Next reboot, reboot the system into H3Droid automatically