- handle the supervisor bit from SR correctly on iframes

- various notes on 060 vs others:
	- 060 has 040 compatible mmu, except pgtables must *not* be on copyback memory
	- 060 has a processor control reg which has a revision number to use in system_info
- notes on ctx switch:
	- must be kept in sync with asm code
	- fsave generate variable size frames, so reserve space and use non-predecrementing EA.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26288 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/arch/m68k/arch_asm.S

@@ -79,6 +79,7 @@ FUNCTION(get_time_base):
 
 
 #warning M68K: FIX m68k_context_switch
+// XXX:sync with arch_thread.c:arch_thread_init_kthread_stack
 // void m68k_context_switch(addr_t *old_sp, addr_t new_sp);
 FUNCTION(m68k_context_switch):
 	// save fp ?
@@ -86,6 +87,7 @@ FUNCTION(m68k_context_switch):
 	movem.l		%d0-%d7/%a0-%a7,-(%sp)
 	fmovem		%fp0-%fp7,-(%sp)
 	fsave		-(%sp)
+#warning M68K: use fixed size for fsave
 
 	// XXX
 	

src/system/kernel/arch/m68k/arch_system_info.cpp

@@ -46,6 +46,7 @@ arch_system_info_init(struct kernel_args *args)
 	sBusClockFrequency = args->arch_args.bus_frequency;
 
 	sCPURevision = args->arch_args.cpu_type; //XXX
+#warning M68K: use 060 PCR[15:8]
 	sCPUType = B_CPU_M68K;
 	
 	return B_OK;

src/system/kernel/arch/m68k/arch_thread.c

@@ -84,8 +84,8 @@ m68k_get_user_iframe(void)
 
 	for (i = thread->arch_info.iframes.index - 1; i >= 0; i--) {
 		struct iframe *frame = thread->arch_info.iframes.frames[i];
-//		if (frame->srr1 & MSR_PRIVILEGE_LEVEL)
-//			return frame;
+		if (frame->sr & (1 << M68K_SR_S) == 0)
+			return frame;
 	}
 
 	return NULL;

src/system/kernel/arch/m68k/arch_user_debugger.cpp

@@ -52,6 +52,8 @@ arch_update_thread_single_step()
 		// 0  1  trace on flow
 		// 1  0  single step
 		// 1  1  undef
+		// note 060 and 020(?) only have T1 bit, 
+		// but this should be compatible as well.
 		if (thread->debug_info.flags & B_THREAD_DEBUG_SINGLE_STEP) {
 			frame->cpu.sr &= ~(M68K_SR_T_MASK);
 			frame->cpu.sr |= (1 << M68K_SR_T1);

src/system/kernel/arch/m68k/arch_vm_translation_map.cpp

@@ -28,10 +28,13 @@
  * so we use a function array to switch to the one we want.
  */
 
+#warning M68K: 060: must *not* have pgtables in copyback cachable mem!!!
+
 //extern struct m68k_vm_ops m68851_vm_ops;
 extern struct m68k_vm_ops m68030_vm_ops;
-//extern struct m68k_vm_ops m68030_vm_ops;
-//extern struct m68k_vm_ops m68030_vm_ops;
+//extern struct m68k_vm_ops m68040_vm_ops;
+// 060 should be identical to 040 except for copyback issue
+//extern struct m68k_vm_ops m68060_vm_ops;
 
 #warning M68K: use a static!
 m68k_vm_ops *get_vm_ops()