Am 02.06.23 um 04:48 schrieb Ben Westover:
One thing I tested was just making the first and second bitmaps the exact same. When I did this, it produced what looked like a color-inverted version of the image. So, the next thing I tested was creating an inverted version of the bitmap, and using that as the second one. This, however, produced the same result. I then tried making the inverted bitmap the first one and the regular one second, and I got an image that looked relatively close to the original. I also tested making them both the inverted bitmap, and this produced the same result. It seems to be that no matter what the second bitmap is changed to, even if you just make it all zeroes, the resulting image still stays the same.
I also always wondered why there are two. The third one definitely is the image outline mask, so that it can have a transparent part where appropriate. I looked at a lot of Apple CHRP scripts with icons, the early ones like Rapsody and Mac OS X Server 1.2 and Mac OS X 10.0 Developer Release and Public Beta, but all I ever found where a) 16x16 icons, which are displayed in the lower right corner next to the media icon in OS Picker. Mostly used for (external) installation media. b) 64x64 icons for installed OSes. c) first two icons always were identical d) third icon is the "outline mask" for transparency to work e) between the three icons may be one empty line (optional) The previous efforts for Apple-specific OF CHRP boot I found: 1) https://lists.debian.org/debian-powerpc/2001/02/msg00061.html 2) https://lists.debian.org/debian-powerpc/2016/02/msg00051.html and mine: 3) https://lists.debian.org/debian-powerpc/2019/06/msg00051.html BTW, if it's "OS Picker" or "Boot Picker" or "Startup Manager" or "boot selector" depends on who wrote the article: OP Picker: https://flylib.com/books/en/3.126.1.46/1/ Boot Picker: https://forums.macrumors.com/threads/the-open-firmware-wiki.2225024/ Startup Manager: https://library.morph.zone/Open_Firmware boot selector: https://mac-classic.com/articles/open-firmware-basics/ Generally, one might call it the Open Firmware boot selection utility on Apple systems... Linux User #330250