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/* Copyright (C) 1994 Free Software Foundation, Inc.
Contributed by Joel Sherrill (jsherril@redstone-emh2.army.mil),
On-Line Applications Research Corporation.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* entry.s
*
* This file contains the entry point for the application.
* The name of this entry point is compiler dependent.
* It jumps to the BSP which is responsible for performing
* all initialization.
*/
.text
.globl start | Default entry point
.globl _start | Default entry point
.globl M68Kvec | Vector Table
.globl _M68Kvec | Vector Table
start:
_start:
M68Kvec: | standard location for vectors
_M68Kvec: | standard location for vectors
nop | for linkers with problem
| using location zero as entry
jmp around
.space 4088 | to avoid initial intr stack
| from 135BUG on MVME13? as entry
| and start code at 0x4000
around:
move.w %sr,initial_sr | save initial values
movec %isp,%a0
movel %a0,initial_isp
movec %usp,%a0
movel %a0,initial_usp
movec %msp,%a0
movel %a0,initial_msp
oriw #0x0700,%sr | INTERRUPTS OFF!!!
|
| zero out uninitialized data area
|
zerobss:
moveal #end,%a0 | find end of .bss
moveal #_bss_start,%a1 | find beginning of .bss
movel #0,%d0
loop: movel #0,%a1@+ | to zero out uninitialized
cmpal %a0,%a1
jlt loop | loop until _end reached
movel #heap_size,__C_heap_size | set ___C_heap_size
movel #heap_memory,__C_heap_start | set ___C_heap_start
moveal #interrupt_stack_end,%a0 | set interrupt stack pointer
movec %a0,%isp
moveal #stack_end,%a0 | set master stack pointer
movec %a0,%msp
moveal #stack_end,%a6 | set base pointer
movw #0x3000,%sr | SUPV MODE,INTERRUPTS ON!!!
#ifdef NEED_UNDERSCORES
jsr __Board_Initialize | initialize the board
#else
jsr _Board_Initialize | initialize the board
#endif
move.l #0,%sp@- | envp = NULL
move.l #0,%sp@- | argv = NULL
move.l #0,%sp@- | argc = NULL
#ifdef NEED_UNDERSCORES
jsr ___libc_init | initialize the library and
| call main
#else
jsr __libc_init | initialize the library and
| call main
#endif
add.l #12,%sp
move.l #0,%sp@- | argc = NULL
jsr __exit | call the Board specific exit
addq.l #4,%sp
move.l initial_isp,%a0 | if __exit returns then we can
movec %a0,%isp | restore the initial values
move.l initial_usp,%a0
movec %a0,%usp
move.l initial_msp,%a0
movec %a0,%msp
move.w initial_sr,%sr
rts
.bss
/*
* So initial stack registers and status register can be saved.
*/
#define DECLARE_SPACE(_name,_space,_align) \
.globl _name ; \
.align _align ; \
_name##: .space _space
#define DECLARE_LABEL(_name) \
.globl _name ; \
_name##:
#define DECLARE_PTR(_name) DECLARE_SPACE(_name,4,2)
#define DECLARE_U32(_name) DECLARE_SPACE(_name,4,2)
#define DECLARE_U16(_name) DECLARE_SPACE(_name,2,1)
DECLARE_U32(initial_isp)
DECLARE_U32(initial_msp)
DECLARE_U32(initial_usp)
DECLARE_U16(initial_sr)
/*
* Require environment stuff
*/
DECLARE_LABEL(_environ)
DECLARE_PTR(environ)
DECLARE_LABEL(_errno)
DECLARE_U32(errno)
/*
* Stack Size and Space
*/
.set stack_size, 0x20000
DECLARE_SPACE(stack_memory,stack_size,4)
DECLARE_LABEL(stack_end)
DECLARE_SPACE(interrupt_stack_memory,0x1000,4)
DECLARE_LABEL(interrupt_stack_end)
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