;-------------------------------------------------------------------------- ; crtxinit.asm :- C run-time: copy XINIT to XISEG ; ; Copyright (C) 2004, Erik Petrich ; ; This library is free software; you can redistribute it and/or modify it ; under the terms of the GNU General Public License as published by the ; Free Software Foundation; either version 2, or (at your option) any ; later version. ; ; This library is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ; GNU General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with this library; see the file COPYING. If not, write to the ; Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, ; MA 02110-1301, USA. ; ; As a special exception, if you link this library with other files, ; some of which are compiled with SDCC, to produce an executable, ; this library does not by itself cause the resulting executable to ; be covered by the GNU General Public License. This exception does ; not however invalidate any other reasons why the executable file ; might be covered by the GNU General Public License. ;-------------------------------------------------------------------------- ; Set DUAL_DPTR to 1 and reassemble if your derivative has dual data pointers ; Especially useful if movx @Ri cannot go beyond the first 256 bytes of xdata ; due to lack of P2 or _XPAGE ; If the derivative has auto-toggle or auto-increment it can be further optimized DUAL_DPTR = 0 .area CSEG (CODE) .area GSINIT0 (CODE) .area GSINIT1 (CODE) .area GSINIT2 (CODE) .area GSINIT3 (CODE) .area GSINIT4 (CODE) .area GSINIT5 (CODE) .area GSINIT (CODE) .area GSFINAL (CODE) .area GSINIT3 (CODE) .if DUAL_DPTR .globl _DPS ; assume DPSEL is in DPS bit0 __mcs51_genXINIT:: mov r1,#l_XINIT mov a,r1 orl a,#(l_XINIT >> 8) jz 00003$ mov r2,#((l_XINIT+255) >> 8) orl _DPS,#0x01 ; set DPSEL, select DPTR1 mov dptr,#s_XINIT ; DPTR1 for code dec _DPS ; clear DPSEL, select DPTR0 mov dptr,#s_XISEG ; DPTR0 for xdata 00001$: clr a inc _DPS ; set DPSEL, select DPTR1 movc a,@a+dptr inc dptr dec _DPS ; clear DPSEL, select DPTR0 movx @dptr,a inc dptr djnz r1,00001$ djnz r2,00001$ 00003$: .else .globl __XPAGE __mcs51_genXINIT:: mov r1,#l_XINIT mov a,r1 orl a,#(l_XINIT >> 8) jz 00003$ mov r2,#((l_XINIT+255) >> 8) mov dptr,#s_XINIT mov r0,#s_XISEG mov __XPAGE,#(s_XISEG >> 8) 00001$: clr a movc a,@a+dptr movx @r0,a inc dptr inc r0 cjne r0,#0,00002$ inc __XPAGE 00002$: djnz r1,00001$ djnz r2,00001$ mov __XPAGE,#0xFF 00003$: .endif