several features are now optional, added legacy BASIC memory model

c64/kernal/,aliases.s

@@ -62,6 +62,8 @@
 	.label enable_case_switch = $0291
 	.label screen_scroll_disable = $0292
 
+#if CONFIG_MEMORY_MODEL_60K
+
 	// Under-ROM routines
 	// (BASIC also includes them. XXX - We should de-duplicate them in a safe manner)
 	.label missed_nmi_flag = $2A7
@@ -71,3 +73,4 @@
 	.label memmap_allram = tiny_nmi_handler+memmap_allram_routine-tiny_nmi_handler_routine
 	.label memmap_normal = tiny_nmi_handler+memmap_normal_routine-tiny_nmi_handler_routine
 
+#endif // CONFIG_MEMORY_MODEL_60K

c64/kernal/f34a.open.s

@@ -81,8 +81,10 @@ open_iec:
 	jmp kernalerror_DEVICE_NOT_FOUND
 !:
 
+#if CONFIG_MEMORY_MODEL_60K
 	// We need our helpers to get to filenames under ROMs or IO area
 	jsr install_ram_routines
+#endif
 
 	// Send command ('file name')
 	jsr lvs_send_file_name

c64/kernal/f4a5.load.s

@@ -31,8 +31,10 @@ LOAD:
 	// Reset status
 	jsr kernalstatus_reset
 
+#if CONFIG_MEMORY_MODEL_60K
 	// We need our helpers to get to filenames under ROMs or IO area
 	jsr install_ram_routines
+#endif
 
 	// Allow platform-specific routine to takeover the flow
 	TARGET_HOOK_LOAD()

c64/kernal/fda3.ioinit.s

@@ -20,23 +20,51 @@ IOINIT:
 	sta CPU_R6510
 	stx CPU_D6510
 
-	// Silence the SID chips under common addresses
+	// Silence the SID chips, depending on the configuration
 
+#if !CONFIG_SID_D4XX
+	lda SID_SIGVOL
+	and #$F0
+	sta SID_SIGVOL
+#endif // !CONFIG_SID_D4XX
+
+#if CONFIG_SID_D4XX || CONFIG_SID_D5XX
 	ldy #$00
 !:
-	// SIDs under $D4xx
+
+#if CONFIG_SID_D4XX 
 	lda SID_SIGVOL, Y
 	and #$F0
 	sta SID_SIGVOL, Y
+#endif // CONFIG_SID_D4XX
+
+#if CONFIG_SID_D5XX 
 	// SIDs under $D5xx
 	lda SID_SIGVOL + $100, Y
 	and #$F0
 	sta SID_SIGVOL + $100, Y
+#endif // CONFIG_SID_D4XX
+
 	tya
 	clc
 	adc #$20
 	tay
 	bne !-
+#endif // CONFIG_SID_D4XX || CONFIG_SID_D5XX
+
+#if CONFIG_SID_2ND
+	lda SID_SIGVOL - SID_BASE + CONFIG_SID_2ND_ADDRESS
+	and #$F0
+	sta SID_SIGVOL - SID_BASE + CONFIG_SID_2ND_ADDRESS
+#endif // CONFIG_SID_2ND
+
+#if CONFIG_SID_3RD
+	lda SID_SIGVOL - SID_BASE + CONFIG_SID_3RD_ADDRESS
+	and #$F0
+	sta SID_SIGVOL - SID_BASE + CONFIG_SID_3RD_ADDRESS
+#endif // CONFIG_SID_3RD
+
+    // Initialize CIAs
 
 	// XXX: calibrate TOD for both CIA's, see here: https://codebase64.org/doku.php?id=base:efficient_tod_initialisation
 

c64/kernal/lvs_helpers.s

@@ -8,8 +8,14 @@ lvs_send_file_name:
 lvs_send_file_name_loop:
 	cpy FNLEN
 	beq lvs_send_file_name_done
-	ldx #<current_filename_ptr
+
+#if CONFIG_MEMORY_MODEL_60K
+	ldx #<current_filename_ptr+0
 	jsr peek_under_roms
+#else // CONFIG_MEMORY_MODEL_38K
+	lda (current_filename_ptr),y
+#endif
+
 	iny
 	// Set Carry flag on the last file name character, to mark EOI
 	cpy FNLEN
@@ -73,8 +79,14 @@ lvs_display_searching_for:
 !:
 	cpy FNLEN
 	beq lvs_display_end
-	ldx #<current_filename_ptr
+
+#if CONFIG_MEMORY_MODEL_60K
+	ldx #<current_filename_ptr+0
 	jsr peek_under_roms
+#else // CONFIG_MEMORY_MODEL_38K
+	lda (current_filename_ptr),y
+#endif
+
 	jsr JCHROUT
 	iny
 	jmp !-

c64/kernal/under_rom_routines.s

@@ -4,6 +4,8 @@
 // in ,aliases.s.
 // Thus those addresses are expressed using formulae.
 
+#if CONFIG_MEMORY_MODEL_60K
+
 install_ram_routines:
 	// Copy routines into place
 	ldx #ram_routines_end-ram_routines_start-1
@@ -62,3 +64,5 @@ memmap_allram_routine:
 	rts
 
 ram_routines_end:
+
+#endif // CONFIG_MEMORY_MODEL_60K