Hi Brad, On Sun, 20 Sep 2020 19:14:21 -0700 Brad Boyer <flar@allandria.com> wrote: > [...] > This utility is abusing /dev/adb not to send an actual ADB message > but instead to talk to the driver which owns ADB on the current > system. The only mesage type all ADB drivers are required to handle > is ADB_PACKET (which is message type 0x0). In fact, three of the > five ADB drivers in the kernel only know about ADB_PACKET. The > first byte of the write is the message type, and the rest is the > message content. I suppose it's not abuse since the driver was > specifically written to allow this, but it still seems a little > non-intuitive to use this device for something that's not ADB. > > That program is sending a raw Cuda command (message type 0x1), so > it will only work on systems that have Cuda whereas your PowerBook > would have PMU instead. The PMU driver emulates Cuda request 0x3 > (CUDA_GET_TIME) but doesn't emulate the more complex call being made > to set the boot time (0xb which is CUDA_POWERUP_TIME). I don't see > any indication the PMU is even capable of this functionality. My > guess is that there isn't any way to make this work on your system. > > The hardware targeted by this program was only in desktop models, > and not all desktop Macs have it either. That chip was introduced > late in the m68k time frame and discontinued about the time Apple > switched to AGP video cards. That iMac would be too new to still > have Cuda and would instead also have PMU just like the PowerBook. Thank you for the explanation. This desktop has power-on timer functionality. I tested it set using OS X 10.4's pmset command. I think there may be a PMU command for this that we don't know about. I might try to run Mac OS in qemu to see if I can trace its communication with the PMU to find it. Charles
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