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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 # GNU960 default entry point
start:
mov 3, r12
modpc r12, r12, r12 # enable tracing/trace faults
mov g5, g5 # NOP
mov 0, g14 # initialize constant for C
/*
* zero out uninitialized data area
*/
zerobss:
lda _end, r4 /* find end of .bss */
lda _bss_start, r5 /* find beginning of .bss */
ldconst 0, r6
loop: st r6, (r5) /* to zero out uninitialized */
addo 4, r5, r5 /* data area */
cmpobl r5, r4, loop /* loop until _end reached */
lda heap_memory, r12 /* tell C lib where heap is */
st r12,___C_heap_start
lda heap_size, r12 /* tell C lib how big heap is */
st r12,___C_heap_size
lda stack_memory,r12 /* set up stack pointer: */
mov r12, sp
mov 0, g14 /* initialize constant for C */
call init_frames
ret /* return to monitor */
init_frames:
ldconst 0x3b001000, g0
ldconst 0x00009107, g1
modac g1, g0, g0 /* set AC controls */
/*
* Call application mainline.
* Someday, real values of argc and argv will be set up.
* For now, they are set to 0.
*/
callx __Board_Initialize /* Initialize the board */
ldconst 0,g0
ldconst 0,g1
ldconst 0,g2
callx ___libc_init /* initialize the library and */
/* call main */
/*
* if we return from main, we have "fallen" off the end
* of the program, therefore status is 0
* so move 0 to g0 (exit parameter)
*/
mov 0, g0
callx __exit
ret
/*
* Data Declarations. Start with a macro which helps declare space.
*/
#define DECLARE_SPACE(_name,_space,_align) \
.globl _name ; \
.align _align ; \
.comm _name##,_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)
/*
* 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)
/*
* Heap Size and Space
*/
.set heap_size, 0x20000
DECLARE_SPACE(heap_memory,heap_size,4)
DECLARE_LABEL(heap_end)
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