initial concept of ROM versioning, still needs quite some work

c64/basic/,imports.s

@@ -4,6 +4,9 @@
 #import "KERNAL_combined.sym"
 
 
+.label panic_vector        = KERNAL.panic_vector
+.label rom_revision_kernal = KERNAL.rom_revision_kernal
+
 #if CONFIG_DBG_PRINTF
 .label printf              = KERNAL.printf
 #endif

c64/basic/basic_cold_start.s

@@ -3,6 +3,16 @@
 
 basic_cold_start:
 
+	// Before doing anything, check if we have a compatible Kernal
+
+	ldy #(__rom_revision_basic_end - rom_revision_basic - 1)
+!:
+	lda rom_revision_basic, y
+	cmp rom_revision_kernal, y
+	bne basic_cold_start_rom_mismatch
+	dey
+	bpl !-
+
 	// Setup vectors at $300
 	ldy #$0B
 !:
@@ -32,3 +42,7 @@ basic_cold_start:
 
 	// jump into warm start loop
 	jmp basic_warm_start
+
+basic_cold_start_rom_mismatch:
+
+	panic #$01

c64/basic/bf52.interop

@@ -0,0 +1,2 @@
+
+Special case - we need a constant memory location where we can put an ID and a revision string. According to Compute's Mapping the Commodore 64 (page 117) this area is unused - so a perfect place.

c64/basic/bf52.rom_revision_basic.s

@@ -0,0 +1,25 @@
+
+//
+// !!! PROPOSAL ONLY !!! PROPOSAL ONLY !!! NOT FOR USING EXTERNALLY YET !!!
+//
+//
+// Do not change! Locations of the following data should be constant - now and forever!
+//
+// If you want to integrate Open ROMs support in your emulator, FPGA ccomputer, etc. - this
+// is the official way to recognize the ROM and it's revision.
+//
+
+
+rom_revision_basic:
+
+	// $BF52
+
+	.text "OR"               // Magic string, after "Open ROMs"
+	.byte CONFIG_ID          // Config file ID, might change between revisions
+
+rom_revision_basic_string:
+
+	.text "DEVEL SNAPSHOT"   // Actual ROM revision string
+	.byte $00
+
+__rom_revision_basic_end:

c64/basic/e422.initmsg.jmp.s

@@ -0,0 +1,11 @@
+
+//
+// Well-known BASIC routine, described in:
+//
+// - [CM64] Compute's Mapping the Commodore 64 - page 212
+//
+// Prints the start-up messages
+//
+
+INITMSG:
+	jmp initmsg_real

c64/basic/initmsg_real.s

@@ -1,13 +1,8 @@
 
-//
-// Well-known BASIC routine, described in:
-//
-// - [CM64] Compute's Mapping the Commodore 64 - page 212
-//
-// Prints the start-up messages
-//
+// Routine is too long to fit in the original location
 
-INITMSG:
+
+initmsg_real:
 
 	// Print startup banner, up to 255 characters
 	ldx #$00
@@ -19,6 +14,10 @@ INITMSG:
 	bne !-
 
 !:
+	// Print ROM revision
+	lda #<rom_revision_basic_string
+	ldy #>rom_revision_basic_string
+	jsr STROUT
 
 	// Print PAL/NTSC, if configured
 
@@ -26,6 +25,9 @@ INITMSG:
 	jsr print_pal_ntsc
 #endif
 
+	jsr initmsg_double_return
+	jsr print_return
+
 	// Work out free bytes, display them
 	jsr basic_do_new
     sec
@@ -41,6 +43,6 @@ INITMSG:
 	ldx #34
 	jsr print_packed_message
 
-	// XXX put them into packed message
+initmsg_double_return:
 	jsr print_return
 	jmp print_return