2001-05-14 Till Straumann <strauman@slac.stanford.edu>

* rtems/powerpc/registers.h, rtems/score/ppc.h: Per PR213, add
	the following:
	    - support for the MPC74000 (AKA G4); there is no
	      AltiVec support yet, however.
	    - the cache flushing assembly code uses hardware-flush on the G4.
	      Also, a couple of hardcoded numerical values were replaced
	      by more readable symbolic constants.
	    - extended interrupt-disabled code section so enclose the entire
	      cache flush/invalidate procedure (as recommended by the book).
	      This is not (latency) critical as it is only used by
	      init code but prevents possible corruption.
	    - Trivial page table support as been added.
	      (1:1 effective-virtual-physical address mapping which is only
	      useful only on CPUs which feature hardware TLB replacement,
	      e.g. >604.  This allows for write-protecting memory regions,
	      e.g. text/ro-data which makes catching corruptors a lot easier.
	      It also frees one DBAT/IBAT and gives more flexibility
	      for setting up address maps :-)
	    - setdbat() allows changing BAT0 also (since the BSP may use
	      a page table, BAT0 could be available...).
	    - asm_setdbatX() violated the SVR ABI by using
	      r20 as a scratch register; changed for r0
	    - according to the book, a context synchronizing instruction is
	      necessary prior to and after changing a DBAT -> isync added

c/src/lib/libcpu/powerpc/shared/include/cpuIdent.h

@@ -27,6 +27,7 @@ typedef enum
   PPC_750 = 0x8,
   PPC_604e = 0x9,
   PPC_604r = 0xA,
+  PPC_7400 = 0xA,
   PPC_620 = 0x16,
   PPC_860 = 0x50,
   PPC_821 = PPC_860,
@@ -38,6 +39,7 @@ typedef unsigned short ppc_cpu_revision_t;
 
 extern ppc_cpu_id_t get_ppc_cpu_type ();
 extern ppc_cpu_id_t current_ppc_cpu;
+extern char *get_ppc_cpu_type_name(ppc_cpu_id_t cpu);
 extern ppc_cpu_revision_t get_ppc_cpu_revision ();
 extern ppc_cpu_revision_t current_ppc_revision;
 #endif /* ASM */