--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/os9/level2/boot.asm	Mon Jul 23 16:07:12 2018 +0900
@@ -0,0 +1,94 @@
+********************************************************************
+* Boot - V09 Boot module
+*
+* $Id: boot_1773.asm,v 1.1.1.1 2001/02/21 23:30:54 boisy Exp $
+*
+* Ed.    Comments                                       Who YY/MM/DD
+* ------------------------------------------------------------------
+
+         nam   Boot
+         ttl   v09 Boot module
+
+         ifp1
+         use   defsfile
+         endc
+
+*
+*  map extended rom on page 0x40-
+*  first two bytes are extra rom module size 
+
+tylg     set   Systm+Objct
+atrv     set   ReEnt+rev
+rev      set   $01
+edition  set   1
+
+         mod   eom,name,tylg,atrv,start,size
+
+size     equ   .
+
+name     fcs   /Boot/
+         fcb   edition
+
+start    
+         lbra    entry
+         lbra    btdebug
+entry
+         ldy    #$40    extended rom page no. 
+         clra
+         clrb
+         pshs   d,x,y,u
+         tfr    d,x
+         leay   4,s    pointer to page no
+     **  read boot rom file size
+         os9    F$LDDDXY 
+         bcs    last
+         addb   #$ff     
+         adca   #0
+         clrb
+         std   ,s       size return as d
+     ** OS9 lv2 use $a000-$dfff as a temporary page
+     ** demand at least that size ( ROM start at $ed00 )
+         cmpa   #$ed-$a0
+         bhi    ok
+         lda    #$ed-$a0
+ok
+         os9    F$BtMem
+         bcs    last
+     **  u points the memory
+         stu    2,s      return as x
+         ldd    ,s
+         std    6,s
+         ldx    #0
+     ** copy to Bt BtRAM
+pagel    ldd    #$2000
+         cmpd   6,s
+         blo    lo
+         ldd    6,s
+lo       tfr    d,y
+         lda    5,s
+         sta    $ffa0
+         tfr    y,d
+loop     ldy    ,x++
+         sty    ,u++
+         subd   #2
+         bne    loop    
+         clr    $ffa0    back to system map
+         ldd    6,s
+         subd   #$2000
+         bmi    last     all transfered
+         std    6,s
+     ** 2k boundary
+         inc    5,s
+         ldx    #0
+         bra    pagel
+last     clr    $ffa0
+         puls   d,x,y,u,pc
+
+      ** put lbsr btdebug on <$5e
+btdebug  anda   #$7f
+         sta    $ff81
+         rts
+
+         emod
+eom      equ   *
+         end