Internal SSD Dualboot [Recalbox & Mint]

[zzapzzap]

Hey guys, I'm new to all these Linux things. I have spare Zotac ZBOX AD02 with internal SSD drive that I'm willing to make into retro-game console but also want keep it usable as fully functional PC when needed. So I installed Recalbox on that SSD using Etcher on my stationary PC, then threw it into Zbox. Then I turned it on and made sure it all works, changes saves, etc. Then I created bootable flash drive with latest Mint on it. Loaded it and used Gpart to shrink that SHARE partition a little bit because it took whole free space. Then I created new partition and installed Mint there. During installation it said that there's another OS installed and I choosed option to install Mint "next to it". After reboot there's no GRUB screen on load, it simply jumps right into Mint. I installed grub-customizer and boom - no traces of Recalboxt left there. So now I wonder where I've made a wrong turn and how it's all should be done so it works. Here some ugly pictures of my pitiful work: https://imgur.com/a/jGeRdxp

[Zing]

@zzapzzap Hello! See if this link helps you:
https://forum.recalbox.com/topic/15678/dualboot-recalbox-windows-sur-pcs-laptops-avec-bios-ou-uefi