Note on multi-architecture kernels: most architecture dependent traps are
forked off directly by having a separate trap table for each (sun4,sun4c,sun4m)
This reduces the number of tests on `cputyp' significantly, and it's easier
on the mind. There are still some entry points that need to test `cputyp',
most notably microtime().. yuck.
Note: multi-architecture kernels use function pointers for several PMAP
entry points.
Cut down the `#if defined(SUN4*)' mess severely by using CPU_ISSUN4*
macros (see machine/param.h) wherever possible.
* cut-and-paste all the code for both r2000 (MIPS-I) and r4000 (MIPS-III)
into both the pica and pmax locore.S.
* Change the names of the small segments of vector code that are
bcopied to the machine vector locations, to avoid clashing.
Get rid of the Sprite MachXXX names for the vector code, and
use use mips_r2000_xxx and mips_r4000_xxx instead.
Update the names used in the vector-copying code and trap handlers
to match.
* Most of the rest of the pica locore.S was copied from the pmax
locore.S, and then edited to work on an r4000. The names of
functions and of manifest constants stayed the same, although
both assmbler code and constant values changed.
cut-and-paste such code into contiguous blocks protected by
#if / #endif. Much of the cache and trap-handling code
needs r3000-only register fields, on the r3000, and r4000-only
insns and registers on the r4000.
* change the pmax r2000 exception-handling code to extract a trap
code with the user/kernel bit at 0x20 rather than 0x10.
(r2000s have 4-bit execption codes, r4000s have 5-bit.)
Use the a 16 from-user-space + 16-from-kernel space jump table,
just like on the r4000 pica port.
* add NOPs to the common code where required by the r4000 pipeline
constraints.
* add _C_LABEL() macros to the r4000 locore.
Comitted to provide a snapshot for others to test, and work on a cleaner merge.
pk