some of the IPI mechanisms used by the common MIPS SMP code so we could use
the multicast IPI facilities, on GXemul as well as on several real hardware
platforms, and the ability to have multiple hard IPI types.
entirely of one machdep file lifted from the MALTA port, as well as
a low-level console and tty driver for the gxemul debugging console
device (the emulators stdio). As with many low-level embedded and
hypervisor console devices, it is polled only, so we drive TTY I/O
from a callout; we are perhaps a bit too aware of the MIPS physical
maps in order to attach the console before newbus comes to life.
The sample kernel configuration depends on an MD-based root file
system, which is not provided. However, any 64-bit, big-endian
userspace image (such as one generated for MALTA) should work.
This will hopefully be supplemented by additional device drivers for
gxemul-specific hardware simulations from Juli Mallett. We have
found oldtestmips quite useful for testing and improving aspects of
the MIPS port, so it's worth supporting better in FreeBSD.
Requested by: theraven, jmallett
Sponsored by: DARPA, AFRL
MFC after: 3 weeks
