;;; -*- asm -*-
|
;;; -*- asm -*-
|
;;; $Id: startup.a51 395 2011-07-17 22:02:55Z mueller $
|
;;; $Id: startup.a51 395 2011-07-17 22:02:55Z mueller $
|
;;;
|
;;;
|
;;;-----------------------------------------------------------------------------
|
;;;-----------------------------------------------------------------------------
|
;;; Startup code
|
;;; Startup code
|
;;;-----------------------------------------------------------------------------
|
;;;-----------------------------------------------------------------------------
|
;;; Code taken from USRP2 firmware (GNU Radio Project), version 3.0.2,
|
;;; Code taken from USRP2 firmware (GNU Radio Project), version 3.0.2,
|
;;; Copyright 2003 Free Software Foundation, Inc.
|
;;; Copyright 2003 Free Software Foundation, Inc.
|
;;;-----------------------------------------------------------------------------
|
;;;-----------------------------------------------------------------------------
|
;;; This code is part of usbjtag. usbjtag is free software; you can redistribute
|
;;; This code is part of usbjtag. usbjtag is free software; you can redistribute
|
;;; it and/or modify it under the terms of the GNU General Public License as
|
;;; it and/or modify it under the terms of the GNU General Public License as
|
;;; published by the Free Software Foundation; either version 2 of the License,
|
;;; published by the Free Software Foundation; either version 2 of the License,
|
;;; or (at your option) any later version. usbjtag is distributed in the hope
|
;;; or (at your option) any later version. usbjtag is distributed in the hope
|
;;; that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
|
;;; that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
|
;;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
;;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
;;; GNU General Public License for more details. You should have received a
|
;;; GNU General Public License for more details. You should have received a
|
;;; copy of the GNU General Public License along with this program in the file
|
;;; copy of the GNU General Public License along with this program in the file
|
;;; COPYING; if not, write to the Free Software Foundation, Inc., 51 Franklin
|
;;; COPYING; if not, write to the Free Software Foundation, Inc., 51 Franklin
|
;;; St, Fifth Floor, Boston, MA 02110-1301 USA
|
;;; St, Fifth Floor, Boston, MA 02110-1301 USA
|
;;;-----------------------------------------------------------------------------
|
;;;-----------------------------------------------------------------------------
|
|
|
;;; The default external memory initialization provided by sdcc is not
|
;;; The default external memory initialization provided by sdcc is not
|
;;; appropriate to the FX2. This is derived from the sdcc code, but uses
|
;;; appropriate to the FX2. This is derived from the sdcc code, but uses
|
;;; the FX2 specific _MPAGE sfr.
|
;;; the FX2 specific _MPAGE sfr.
|
|
|
|
|
;; .area XISEG (XDATA) ; the initialized external data area
|
;; .area XISEG (XDATA) ; the initialized external data area
|
;; .area XINIT (CODE) ; the code space consts to init XISEG
|
;; .area XINIT (CODE) ; the code space consts to init XISEG
|
.area XSEG (XDATA) ; zero initialized xdata
|
.area XSEG (XDATA) ; zero initialized xdata
|
.area USBDESCSEG (XDATA) ; usb descriptors
|
.area USBDESCSEG (XDATA) ; usb descriptors
|
|
|
|
|
.area CSEG (CODE)
|
.area CSEG (CODE)
|
|
|
;; sfr that sets upper address byte of MOVX using @r0 or @r1
|
;; sfr that sets upper address byte of MOVX using @r0 or @r1
|
_MPAGE = 0x0092
|
_MPAGE = 0x0092
|
|
|
__sdcc_external_startup::
|
__sdcc_external_startup::
|
;; This system is now compiled with the --no-xinit-opt
|
;; This system is now compiled with the --no-xinit-opt
|
;; which means that any initialized XDATA is handled
|
;; which means that any initialized XDATA is handled
|
;; inline by code in the GSINIT segs emitted for each file.
|
;; inline by code in the GSINIT segs emitted for each file.
|
;;
|
;;
|
;; We zero XSEG and all of the internal ram to ensure
|
;; We zero XSEG and all of the internal ram to ensure
|
;; a known good state for uninitialized variables.
|
;; a known good state for uninitialized variables.
|
|
|
; _mcs51_genRAMCLEAR() start
|
; _mcs51_genRAMCLEAR() start
|
mov r0,#l_XSEG
|
mov r0,#l_XSEG
|
mov a,r0
|
mov a,r0
|
orl a,#(l_XSEG >> 8)
|
orl a,#(l_XSEG >> 8)
|
jz 00002$
|
jz 00002$
|
mov r1,#((l_XSEG + 255) >> 8)
|
mov r1,#((l_XSEG + 255) >> 8)
|
mov dptr,#s_XSEG
|
mov dptr,#s_XSEG
|
clr a
|
clr a
|
|
|
00001$: movx @dptr,a
|
00001$: movx @dptr,a
|
inc dptr
|
inc dptr
|
djnz r0,00001$
|
djnz r0,00001$
|
djnz r1,00001$
|
djnz r1,00001$
|
|
|
;; We're about to clear internal memory. This will overwrite
|
;; We're about to clear internal memory. This will overwrite
|
;; the stack which contains our return address.
|
;; the stack which contains our return address.
|
;; Pop our return address into DPH, DPL
|
;; Pop our return address into DPH, DPL
|
00002$: pop dph
|
00002$: pop dph
|
pop dpl
|
pop dpl
|
|
|
;; R0 and A contain 0. This loop will execute 256 times.
|
;; R0 and A contain 0. This loop will execute 256 times.
|
;;
|
;;
|
;; FWIW the first iteration writes direct address 0x00,
|
;; FWIW the first iteration writes direct address 0x00,
|
;; which is the location of r0. We get lucky, we're
|
;; which is the location of r0. We get lucky, we're
|
;; writing the correct value (0)
|
;; writing the correct value (0)
|
|
|
00003$: mov @r0,a
|
00003$: mov @r0,a
|
djnz r0,00003$
|
djnz r0,00003$
|
|
|
push dpl ; restore our return address
|
push dpl ; restore our return address
|
push dph
|
push dph
|
|
|
mov dpl,#0 ; indicate that data init is still required
|
mov dpl,#0 ; indicate that data init is still required
|
ret
|
ret
|
|
|
