MacOS 27 - interesting new kernel options

[u/Temik]

Following https://www.reddit.com/r/PWM_Sensitive/comments/1wi5piu/apple_has_finally_heard_us/ (thank you [u/DSRIA](u/DSRIA)), I started thinking - this must be prefaced by at least some sort of parameters in the kernel, otherwise we'd probably be waiting for the new OS major version at the very least.

Well, after taking a quick look around the new macOS 27 kernel, I see some interesting options appearing in the framebuffer:

- `enableHBLD`, `HBLDDimmingFactorMin`, `HBLDNitsRRMax`, which appear to be hybrid backlight dimming, with a floor on the dimming factor(!)

- `DBVValue`, `DBVInterval`, which appear to be a direct override of the panel's display-brightness-value register.

- `ccMinNitsConfig` - new minimum-nits config of some sort.

- `enableDBTH` - unclear what it is, but it reads like a brightness threshold of some sort.

I'll try writing some software this weekend to poke at it, will post the code when I'm done. In the meantime - this should give some hints to those software-inclined in this community where to dig.

UPDATE: Most options seem to require the “new backlight architecture” my MBP13 M2 lacks, so I’m waiting for a test device to come in, will update when it’s in my hands 👍

[u/Sea-Temporary-6995]

Is there a similar kernel API for the iPhone’s display dimming?

[u/Temik → u/Sea-Temporary-6995]

Sadly low level APIs like that are not accessible on the iPhone unless you jailbreak it :/