From cb2ec4e9f3e6778c266fe7869ce7b0ce5709347b Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Wed, 21 Oct 2020 20:55:16 +0200
Subject: [PATCH] added memory mapping routines to CRT memory layout

---
 src/basic/,imports.s                          |  1 +
 .../board_crt/{crt_init.s => crt_init_map.s}  | 42 ++++++++++++++++---
 2 files changed, 37 insertions(+), 6 deletions(-)
 rename src/kernal/board_crt/{crt_init.s => crt_init_map.s} (83%)

diff --git a/src/basic/,imports.s b/src/basic/,imports.s
index d3ccd633..1ccbe2c2 100644
--- a/src/basic/,imports.s
+++ b/src/basic/,imports.s
@@ -36,6 +36,7 @@
 
 ;; #ALIAS# map_end             = KERNAL_0.map_end
 ;; #ALIAS# map_NORMAL          = KERNAL_0.map_NORMAL
+;; #ALIAS# map_BASIC_1         = KERNAL_0.map_BASIC_1
 
 ;; #ALIAS# M65_MODEGET         = KERNAL_0.M65_MODEGET
 ;; #ALIAS# M65_MODESET         = KERNAL_0.M65_MODESET
diff --git a/src/kernal/board_crt/crt_init.s b/src/kernal/board_crt/crt_init_map.s
similarity index 83%
rename from src/kernal/board_crt/crt_init.s
rename to src/kernal/board_crt/crt_init_map.s
index 0a02c249..b1eced5e 100644
--- a/src/kernal/board_crt/crt_init.s
+++ b/src/kernal/board_crt/crt_init_map.s
@@ -35,6 +35,10 @@
 ; bit 0 - 1 = flash mode activated by jumper
 
 
+crt_init_fail:
+
+	+panic P_ERR_ROM_MISMATCH
+
 crt_init:
 
 	; Setup the cart
@@ -44,8 +48,7 @@ crt_init:
 
 	; Bank-in the first ROM bank
 
-	lda #%00000000
-	sta $DE00
+	jsr map_BASIC_1
 
 	; Check if ROM revision matches the cartridge
 	
@@ -53,18 +56,45 @@ crt_init:
 @1:
 	iny
 	lda $E4B9, y            ; Kernal ROM revision address
-	cmp $9FEC, y
+	cmp $9FEC, y            ; cartridge ROM revision address
 	bne crt_init_fail
 	cmp #$00
 	bne @1
 
-	; Unmap cartridge memory     XXX provide separate map functions
+	; FALLTROUGH
+
+map_NORMAL:
+
+	; Unmap cartridge memory
+
+	php
+	pha
 
 	lda #%00000010
+
+	; FALLTROUGH
+
+map_NORMAL_common:
+
 	sta $DE00
 
+	pla
+	plp
+
 	rts
 
-crt_init_fail:
+map_BASIC_1:
 
-	+panic P_ERR_ROM_MISMATCH
+	php
+	pha
+
+	lda #%00000000
+	beq map_NORMAL_common
+
+map_KERNAL_1:
+
+	php
+	pha
+
+	lda #%00010000
+	bne map_NORMAL_common