The HSI specification is currently incomplete and in active development.
Sample output for my Lenovo P50 Laptop:
Host Security ID: HSI:2+UA!
HSI-1
✔ UEFI dbx: OK
✔ TPM: v2.0
✔ SPI: Write disabled
✔ SPI: Lock enabled
✔ SPI: SMM required
✔ UEFI Secure Boot: Enabled
HSI-2
✔ TPM Reconstruction: Matched PCR0 reading
HSI-3
✘ Linux Kernel S3 Sleep: Deep sleep available
HSI-4
✘ Intel CET: Unavailable
Runtime Suffix -U
✔ Firmware Updates: Newest release is 8 months old
Runtime Suffix -A
✔ Firmware Attestation: OK
Runtime Suffix -!
✔ fwupd plugins: OK
✔ Linux Kernel: OK
✔ Linux Kernel: Locked down
✘ Linux Swap: Not encrypted
If we say that the version format should be the same for the `version_lowest`
and the `version_bootloader` then it does not always make sense to set it at
the same time.
Moving the `version_format` to a standalone first-class property also means it
can be typically be set in the custom device `_init()` function, which means we
don't need to worry about *changing* ther version format as set by the USB and
UDev superclass helpers.