@mladen I dont know how to use dmidecode command but I looked into coreboot tables in boot menu and I found this:
4.6-500-gdd47******-4.6-a86d1b-purism-5 (seems like that is the latest one)
I have only one SSD installed that is Samsung 850 Evo.
Edit: dmidecode -t bios
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.
Handle 0x0000, DMI type 0, 24 bytes
Release Date: //2017
ROM Size: 16 MB
PCI is supported
PC Card (PCMCIA) is supported
BIOS is upgradeable
Selectable boot is supported
ACPI is supported
Targeted content distribution is supported
BIOS Revision: 4.0
Firmware Revision: 0.0