common across many of the 4xx parts. Leaves ibm405gp.h with device
address information specific to the 405GP CPU. Now allows opb.c to
support multiple 4xx CPU types.
documentation:
- Remove "mainbus" altogether.
- The new root is "plb" - the Processor Local Bus.
- Attached to this is the "opb" - the On-chip Peripheral Bus, to which
all the on-chip devices are attached (except the cpu and pci host
bridge).
- Port-specific code can pass an array of 'struct plb_dev' to
config_rootfound() to attach extra devices to the plb. The walnut
port attaches a "pbus" (Peripheral Bus) in here for the RTC and
pc keyboard controller to attach to.
There is still much 405GP specific code; the next round of changes will
generalise this to enable easier support for other 4xx CPUs.
by Eduardo Horvath and Simon Burge of Wasabi Systems.
IBM 4xx series CPU features:
- New pmap and revised trap handler.
- Support on-chip timers, PCI controller, UARTs
- Framework for on-chip ethernet and watchdog timer.
General PowerPC features:
- Add in-kernel PPC floating point emulation
- New in{,4}_cksum that is between 1.5 and 5 times faster than the
old version depending on CPU type.
General changes:
- Kernel support for generic dbsym-style symbols.
