From c818d980a8587977c466fb204c6c015de25b03e6 Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Tue, 20 Oct 2020 23:19:48 +0200
Subject: [PATCH] more works towards CRT ROM layout

---
 src/basic/rom_revision/bf52.rom_revision_basic.s |  2 +-
 src/kernal/board_crt/crt_init.s                  |  9 +++++++++
 src/kernal/init/fce2.hw_entry_reset.s            | 10 +++++++++-
 src/kernal/init/fd50.ramtas.s                    | 12 ++++++++++++
 4 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 src/kernal/board_crt/crt_init.s

diff --git a/src/basic/rom_revision/bf52.rom_revision_basic.s b/src/basic/rom_revision/bf52.rom_revision_basic.s
index ef8c1bec..6bc6892e 100644
--- a/src/basic/rom_revision/bf52.rom_revision_basic.s
+++ b/src/basic/rom_revision/bf52.rom_revision_basic.s
@@ -1,5 +1,5 @@
 ;; #LAYOUT# STD *       #TAKE
-;; #LAYOUT# CRT BASIC_1 #TAKE-OFFSET -2F52
+;; #LAYOUT# CRT BASIC_1 #TAKE-OFFSET -1F66
 ;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
 ;; #LAYOUT# *   BASIC_0 #TAKE
 ;; #LAYOUT# *   *       #IGNORE
diff --git a/src/kernal/board_crt/crt_init.s b/src/kernal/board_crt/crt_init.s
new file mode 100644
index 00000000..69c07dec
--- /dev/null
+++ b/src/kernal/board_crt/crt_init.s
@@ -0,0 +1,9 @@
+;; #LAYOUT# CRT KERNAL_0 #TAKE
+;; #LAYOUT# *   *        #IGNORE
+
+
+crt_init:
+
+	; XXX !!! provide implementation
+	
+	rts
diff --git a/src/kernal/init/fce2.hw_entry_reset.s b/src/kernal/init/fce2.hw_entry_reset.s
index 8cd79829..3867c990 100644
--- a/src/kernal/init/fce2.hw_entry_reset.s
+++ b/src/kernal/init/fce2.hw_entry_reset.s
@@ -39,12 +39,14 @@ hw_entry_reset:
 	; Also, https://codebase64.org/doku.php?id=base:assembling_your_own_cart_rom_image was used
 	; as it shows example startup sequence, to be followe by cartridge creators
 
+!ifndef ROM_LAYOUT_CRT {
+
 	; C64 PRG p269
 	jsr cartridge_check
 	bne @1
 	jmp (ICART_COLD_START)
 @1:
-
+}
 	; Disable the screen (and set 40 columns) to prevent visual glitches later
 	ldx #$28
 	stx VIC_SCROLX
@@ -73,6 +75,12 @@ hw_entry_reset:
 	jsr JCINT
 }
 
+!ifdef ROM_LAYOUT_CRT {
+
+	; Init external ROM
+	jsr crt_init
+}
+
 	; What do we do when finished?  A C64 jumps into the BASIC ROM
 	cli ; allow interrupts to happen
 
diff --git a/src/kernal/init/fd50.ramtas.s b/src/kernal/init/fd50.ramtas.s
index 60197f82..6d28c48f 100644
--- a/src/kernal/init/fd50.ramtas.s
+++ b/src/kernal/init/fd50.ramtas.s
@@ -65,6 +65,17 @@ RAMTAS:
 	ldx #>$0800
 	stx MEMSTR+1
 
+
+!ifdef ROM_LAYOUT_CRT {
+
+	; Set RAM size in MEMSIZEK - skip memory test
+
+	ldy #$A0
+	sty MEMSIZK+1
+	rts
+
+} else {
+
 	; Work out RAM size and put in MEMSIZK
 	; Try to modify $8000, if it fails then RAM ends at $7FFF, else $9FFF
 
@@ -101,6 +112,7 @@ ramtas_32k:
 
 	ldy #$80
 	bne ramtas_xxk ; branch always
+}
 
 } else ifdef CONFIG_PLATFORM_COMMANDER_X16 {