Hmm, today I learned about Lanner Electronics, in Taiwan, who ships a “secure BIOS” product.
Lanner witnesses the growing awareness of potential security risk for the pre-OS level and offers advnaced security features integrated within our exclusive BIOS designs. Lanner’s BIOS firmware offerring including market-proven technologies such as Secure Boot and Intel Boot Guard technology deliver solid commitments for the shield protection against malware, uncertified sequences and other named cyber threats. For specific applications, Lanner’s security-enhanced BIOS can be customized with the services covering DMI data pool, customer logo and password protection.
The page has some download links, last updated in 2018, The doc links work, but the link to the BIOS download doesn’t work (at least for me).