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FreeRTOS-Kernel/Demo/MCF5235_GCC/system/crt0.S
2006-10-09 11:40:24 +00:00

116 lines
3.1 KiB
ArmAsm

/*
FreeRTOS MCF5235 port - Copyright (C) 2006 Christian Walter.
This file is part of the FreeRTOS distribution.
FreeRTOS 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 of the License, or
(at your option) any later version.
FreeRTOS 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 FreeRTOS; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
See http://www.FreeRTOS.org for documentation, latest information, license
and contact details. Please ensure to read the configuration and relevant
port sections of the online documentation.
***************************************************************************
*/
.title "crt0.S"
.extern main
.extern __stack
.extern __bss_start
.extern __text_start
.extern init_main
.equ MCF5XXX_RAMBAR_SPV, 0x00000200
.equ MCF5XXX_RAMBAR_V, 0x00000001
.global start
.align 4
debug:
.word 0x2C80 /* write to CSR */
.word 0x0010
.word 0x0400
.word 0x0000
start:
/* disable all interrupts on startup. */
move.w #0x2700, sr
/* prepare internal SRAM. */
move.l #__SRAM, d0
ori.l #( MCF5XXX_RAMBAR_SPV | MCF5XXX_RAMBAR_V ), d0
movec d0, rambar
/* prepare stack and frame pointer. */
move.l #__stack, sp
link a6, #-8
/* initialize hardware. */
jsr init_main
/* zero out the bss section. */
move.l #__bss_start, d1
move.l #_end, d0
cmp.l d0, d1
jbeq 3f
move.l d1, a0
sub.l d1, d0
subq.l #1, d0
2:
clr.b (a0)+
subq.l #1, d0
jbpl 2b
3:
/* Relocate the data section. */
move.l #__data_load_start, %a0 /* .data in ROM */
move.l #copy_start, %a1 /* .data in RAM */
/* Test if the two sections overlap. This is the case when we are working
* with the debugger and the debugger loads the .data section.
*/
cmpa.l %a0, %a1
beq 2f
1:
/* Have we already copied everything. */
cmpa.l #__data_load_end, %a0
beq 2f
move.b (%a0)+, (%a1)+
bra 1b
2:
/* C library */
move.l #__FINI_SECTION__, -(%sp)
jsr atexit
jsr __INIT_SECTION__
/* call main(int argc, char *argv[] */
move.l #0, -(sp)
move.l #0, -(sp)
move.l #0, -(sp)
jsr main
lea (sp, 12), %sp
/* stop on exit from main. */
1:
halt