ChanServ changed the topic of #asahi-re to: Asahi Linux: porting Linux to Apple Silicon macs | Hardware / boot process / firmware interface reverse engineering | WARNING: this channel (only) may contain binary reverse engineering discussion | RE policy: https://alx.sh/re (MANDATORY READ) | GitHub: https://alx.sh/g | Wiki: https://alx.sh/w | Logs: https://alx.sh/l/asahi-re
phiologe has joined #asahi-re
PhilippvK has quit [Ping timeout: 480 seconds]
skipwich has quit [Ping timeout: 480 seconds]
alyssa has joined #asahi-re
<alyssa>
the relevant string int he firmware has a %d format specifier, it's not hardcoded to 2
<alyssa>
it could be the firmware wants to be generic to different devices (...but it hardcodes H13P in the name lol)
<alyssa>
or it could be that it's computed on the fly, maybe based on what's in use or maybe resoution-- let me try at 1080p
<alyssa>
no dice there either. 🤷
<alyssa>
nini
<alyssa>
[Also, the use of %d instead of %u on scaling syslog implies that dcp rect is actually s32's, but the DCP rejects negative values. Which is a shame, it would've been a lovely way to indicate X/Y flips. Which I know the hardware can do since I know the actual register for it...]
<marcan>
alyssa: maybe "blend" means specificially formats with alpha
<marcan>
that also makes sense, since you'd have two layers with alpha on top of one without
<marcan>
if you're using ARGB for everything that could explain that
<marcan>
re flips, there have to be flags for that somewhere...
<marcan>
should be easy to work out with monitor rotation on macos
Misthios5 has joined #asahi-re
Misthios5 has quit []
Misthios has quit [Quit: Misthios]
Misthios has joined #asahi-re
Misthios has quit []
Misthios has joined #asahi-re
Misthios has quit []
Misthios has joined #asahi-re
al3xtjames2 has joined #asahi-re
al3xtjames has quit [Ping timeout: 480 seconds]
al3xtjames2 is now known as al3xtjames
<alyssa>
alpha is possibly, yeah
<alyssa>
do we know the fourcc for XBGR, though?
<alyssa>
(*is* there a fourcc for it?)
<alyssa>
unless maybe it's still ARGB but with some alpha flpag disabled somewhere
<alyssa>
(or some opaque flag enabled)
PhilippvK has joined #asahi-re
phiologe has quit [Ping timeout: 480 seconds]
<marcan>
alyssa: and yeah, looking at the format codes it sounds like there should be some flag to disable alpha blending?
<marcan>
it doesn't look like there's XBGR
<marcan>
there was one with a non-text code in the past, but I don't recall seeing any of those in DCP
<marcan>
alyssa: looks like that limitation isn't for blending though
<marcan>
it really is just max 2 surfaces at one time
<marcan>
that is so bizarre
<alyssa>
marcan: baffling
<alyssa>
Although I guess it's not super surprising given this was designed for iPhones where you only ever have a primary and an overlay
<marcan>
yeah but the DCP ABI used to have 3 slots, now it has 4... yet it limits it to 2... but the hardware apparently supports 3?
<marcan>
that's so confusing, if they increased the ABI count one would presume they expect to release hardware with more slots, but then they don't even support the existing 3?
<marcan>
maybe it's just Not Done Yet
<alyssa>
🤷
<alyssa>
I'm more wondering how to model this for linux
<alyssa>
(in particular to support broken compositors that expect a cursor plane but ignore overlay planes)
<alyssa>
"Checking that virtualized resources exported to userspace are not oversubscribed. For various reasons it can make sense to expose more planes, crtcs or encoders than which are physically there"
<alyssa>
Oh, like that. Expose a primary, a cursor, and an overlay and reject request sto enable all 3 at once
chadmed has quit [Read error: Connection reset by peer]