adjusted some addresses, added more stubs

c64/basic/init/basic_warm_start_internal.s

@@ -0,0 +1,29 @@
+
+//
+// Continuation of the BASIC cold start routine
+//
+
+basic_warm_start_real:
+
+#if CONFIG_MEMORY_MODEL_60K
+	// We need our helpers to get to filenames under ROMs or IO area
+	jsr install_ram_routines
+#endif
+
+	// If warm start caused by BRK, print it address
+	// XXX sys 58235 also triggers this - to be fixed
+	lda CMP0
+	ora CMP0+1
+	beq !+
+
+	ldx #32
+	jsr print_packed_message
+
+	lda CMP0+1
+	jsr print_hex_byte
+	lda CMP0+0
+	jsr print_hex_byte
+	jsr print_return
+
+!:
+	jmp basic_main_loop

c64/basic/init/e3b7.basic_warm_start.jmp.s

@@ -0,0 +1,5 @@
+// Clear screen etc, show READY prompt.
+
+basic_warm_start:
+
+	jmp basic_warm_start_real

c64/basic/init/e3b7.interop

@@ -0,0 +1,5 @@
+
+This is a well-known address, needed even for some BASIC programming - it's a common target for a SYS command. See for example here:
+
+- http://ready64.org/articoli/_files/043_pokesc64.txt
+  sys 58235 - Warm Start