Whenever a field was added to the end of the Primary System Area (PSA)
record, the offsets of all other fields would change. When reversing NK
version 02.27, I noticed that 32 bytes had been added to the end of the
PSA between 02.27 and 02.28. To build a byte-perfect 02.27, all
references to PSA fields must therefore use the record definition in
NKPublic.s instead of a numeric offset.
In this commit, all PSA references are identified by field name (_FFF if
the field has not yet been reversed).
Version 02.11 of the NanoKernel prints an annotated crash dump of the
EDP. This version has been partly reversed (using Hopper!), and the
sometimes-cryptic EDP field names have been added to EmulatorPublic.a.
This is part of the work to get the mini running well. The
kcPowerDispatch and kcCacheDispatch entry points were explored. The dead
code implementing a Timer "Heartbeat" was also used to label some
structures better.
CPU plugins are code fragment resources that allow the NanoKernel to
perform CPU-specific functions, such as starting or stopping a processor
core or getting core temperature. They live in the Apple CPU Plugins
file. The Power Manager selects a plugin at boot (or doesn't), prepares
and holds it in memory, and registers it with the NanoKernel using
MPRegisterCpuPlugin(). The NanoKernel can then call any of the plugin's
entry points synchronously using its SIGP() function, which is also
exposed via the MPCpuPlugin() call. The plugin return path is tricky,
but involved the ReturnFromInterrupt trap instruction in the emulator
ROM code.
The CPU plugin calling convention is described in the SIGP comments. CPU
plugins operate in the blue address space, but with interrupts disabled
and supervisor mode on.
This code was reversed to get the Mac mini working. It is not clear how
the Power Manager determines CPU temperature when there are no CPU
registers to do this.
Namely queues, semaphores, critical regions, event groups and
"notifications". The MP calls implementing these services have been
named after their MPLibrary wrapper functions. This convention will be
followed in the future (no more NKCreateEvent).
Elliot Nunn