See this thread by user maxirosson if you don't know it already:
56 Hardware Wallets, compared feature by featureThe comparison website he created is awesome and e.g. lists for hardware wallets details like "Secure boot", "Source-available", "Free & open-source (FOSS)", "Reproducible builds" and many more valuable things.
Thanks for that, the thread changed location just shortly after you posted it here
. https://bitcointalk.org/index.php?topic=5560969.0I didn't count how many hardware wallets are "open-source" or not. It's not quite my perception that a majority of devices are closed-source, but I repeat, I didn't count.
I wouldn't consider a hardware wallet at all if it's not open-source. For me it's mandatory that the firmware is open-source and it's a not negotiable property, period!
His comparison website also lists software wallets, definitely worth a visit.
Website is pretty good, it could use some minor usability improvements to get these counts too and scrolling seems a bit slow for me. But you can fast track to a list of open source ones here.
https://thebitcoinhole.com/hardware-wallets/firmware/open-sourceIt is around 30 open source ones, pretty good I would say.