Added a bootable header on bank 1

Konamiman · Nov 30, 2018 · 8e80e51 · 8e80e51
1 parent f5ca04d
commit 8e80e51
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diff --git a/msx/bank1/header.asm b/msx/bank1/header.asm
@@ -0,0 +1,24 @@
+; Rookie Drive USB FDD BIOS
+; By Konamiman, 2018
+;
+; This file defines a ROM header for bank 1, it simply jumps to the initialization
+; routine for bank 0. This header is needed to ensure that the ROM will boot properly
+; even if for some reason the computer resets while executing code in bank 1.
+
+    db "AB"
+    dw BANK1_INIT
+    ds 12
+
+BANK1_INIT:
+    ld hl,BANK1_INIT_DO
+    ld de,0C000h
+    ld bc,BANK1_INIT_DO_END - BANK1_INIT_DO
+    ldir
+    jp 0C000h
+
+BANK1_INIT_DO:
+    xor a
+    ld (ROM_BANK_SWITCH),a
+    ld hl,(4002h)
+    jp (hl)
+BANK1_INIT_DO_END:
diff --git a/msx/rookiefdd.asm b/msx/rookiefdd.asm
@@ -48,6 +48,7 @@ DEFDPB:
 
     org 4000h
 
+    include "bank1/header.asm"
     include "bank1/ch376.asm" ;USB host hardware dependant code
     include "bank1/inihrd_inienv.asm"
     include "bank1/verbose_reset.asm"