ARM: make sure we cleanup after the bootloader

The "2nd" assert that we always ran into was due to bootloader mappings
still being active after VM init. Turns out we missed a call in the
architecture specific code for cleaning this up.

Many thanks to Ingo for spending the time to figure this out!

src/system/kernel/arch/arm/arch_vm.cpp

@@ -28,12 +28,11 @@
 #	define TRACE(x) ;
 #endif
 
-#warning ARM: WRITEME
-
 
 status_t
 arch_vm_init(kernel_args *args)
 {
+	TRACE(("arch_vm_init: entry\n"));
 	return B_OK;
 }
 
@@ -41,12 +40,6 @@ arch_vm_init(kernel_args *args)
 status_t
 arch_vm_init2(kernel_args *args)
 {
-	//	int bats[8];
-	//	int i;
-
-	/**/
-	#warning ARM: WRITEME
-
 	return B_OK;
 }
 
@@ -54,6 +47,7 @@ arch_vm_init2(kernel_args *args)
 status_t
 arch_vm_init_post_area(kernel_args *args)
 {
+	TRACE(("arch_vm_init_post_area: entry\n"));
 	return B_OK;
 }
 
@@ -61,7 +55,9 @@ arch_vm_init_post_area(kernel_args *args)
 status_t
 arch_vm_init_end(kernel_args *args)
 {
-	#warning ARM: WRITEME
+	// Throw away all mappings that are unused by the kernel
+	vm_free_unused_boot_loader_range(KERNEL_LOAD_BASE, KERNEL_SIZE);
+
 	return B_OK;
 }
 
@@ -76,14 +72,21 @@ arch_vm_init_post_modules(kernel_args *args)
 void
 arch_vm_aspace_swap(struct VMAddressSpace *from, struct VMAddressSpace *to)
 {
-	#warning ARM:WRITEME
+	// This functions is only invoked when a userland thread is in the process
-	// m68k_set_pgdir(m68k_translation_map_get_pgdir(&to->TranslationMap()));
+	// of dying. It switches to the kernel team and does whatever cleanup is
+	// necessary (in case it is the team's main thread, it will delete the
+	// team).
+	// It is however not necessary to change the page directory. Userland team's
+	// page directories include all kernel mappings as well. Furthermore our
+	// arch specific translation map data objects are ref-counted, so they won't
+	// go away as long as they are still used on any CPU.
 }
 
 
 bool
 arch_vm_supports_protection(uint32 protection)
 {
+	// TODO check ARM protection possibilities
 	return true;
 }
 
@@ -91,6 +94,7 @@ arch_vm_supports_protection(uint32 protection)
 void
 arch_vm_unset_memory_type(VMArea *area)
 {
+	// TODO
 }