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/* Copyright (C) 1994, 1996, 1997 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 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_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)
|
