| 1 |
2 |
csantifort |
/*----------------------------------------------------------------
|
| 2 |
|
|
// //
|
| 3 |
|
|
// start.S //
|
| 4 |
|
|
// //
|
| 5 |
|
|
// This file is part of the Amber project //
|
| 6 |
|
|
// http://www.opencores.org/project,amber //
|
| 7 |
|
|
// //
|
| 8 |
|
|
// Description //
|
| 9 |
|
|
// Assembly routines for hello-world. //
|
| 10 |
|
|
// As hello-world is a stand-alone application, it needs a //
|
| 11 |
|
|
// simple start function written in assembly to call the //
|
| 12 |
|
|
// C code main() function. //
|
| 13 |
|
|
// //
|
| 14 |
|
|
// Author(s): //
|
| 15 |
|
|
// - Conor Santifort, csantifort.amber@gmail.com //
|
| 16 |
|
|
// //
|
| 17 |
|
|
//////////////////////////////////////////////////////////////////
|
| 18 |
|
|
// //
|
| 19 |
|
|
// Copyright (C) 2010 Authors and OPENCORES.ORG //
|
| 20 |
|
|
// //
|
| 21 |
|
|
// This source file may be used and distributed without //
|
| 22 |
|
|
// restriction provided that this copyright statement is not //
|
| 23 |
|
|
// removed from the file and that any derivative work contains //
|
| 24 |
|
|
// the original copyright notice and the associated disclaimer. //
|
| 25 |
|
|
// //
|
| 26 |
|
|
// This source file is free software; you can redistribute it //
|
| 27 |
|
|
// and/or modify it under the terms of the GNU Lesser General //
|
| 28 |
|
|
// Public License as published by the Free Software Foundation; //
|
| 29 |
|
|
// either version 2.1 of the License, or (at your option) any //
|
| 30 |
|
|
// later version. //
|
| 31 |
|
|
// //
|
| 32 |
|
|
// This source is distributed in the hope that it will be //
|
| 33 |
|
|
// useful, but WITHOUT ANY WARRANTY; without even the implied //
|
| 34 |
|
|
// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //
|
| 35 |
|
|
// PURPOSE. See the GNU Lesser General Public License for more //
|
| 36 |
|
|
// details. //
|
| 37 |
|
|
// //
|
| 38 |
|
|
// You should have received a copy of the GNU Lesser General //
|
| 39 |
|
|
// Public License along with this source; if not, download it //
|
| 40 |
|
|
// from http://www.opencores.org/lgpl.shtml //
|
| 41 |
|
|
// //
|
| 42 |
|
|
----------------------------------------------------------------*/
|
| 43 |
|
|
|
| 44 |
|
|
.section .text
|
| 45 |
|
|
.globl start
|
| 46 |
|
|
_start:
|
| 47 |
|
|
/* Switch to User Mode */
|
| 48 |
|
|
/* and unset interrupt mask bits */
|
| 49 |
|
|
mov r0, #0x00000000
|
| 50 |
|
|
teqp pc, r0
|
| 51 |
|
|
|
| 52 |
|
|
@ Enable the cache
|
| 53 |
|
|
mov r0, #0xffffffff
|
| 54 |
11 |
csantifort |
mcr 15, 0, r0, cr3, cr0, 0 @ cacheable area
|
| 55 |
2 |
csantifort |
mov r0, #1
|
| 56 |
11 |
csantifort |
mcr 15, 0, r0, cr2, cr0, 0 @ cache enable
|
| 57 |
2 |
csantifort |
|
| 58 |
|
|
@ initialize the stack pointer
|
| 59 |
|
|
ldr sp, AdrStack
|
| 60 |
|
|
|
| 61 |
|
|
@ jump to main
|
| 62 |
|
|
.extern main
|
| 63 |
|
|
bl main
|
| 64 |
|
|
|
| 65 |
|
|
b _testpass
|
| 66 |
|
|
|
| 67 |
|
|
/* stack at top of ddr3 memory space */
|
| 68 |
|
|
AdrStack: .word 0x8000000
|
| 69 |
|
|
|
| 70 |
|
|
|
| 71 |
43 |
csantifort |
.section .bss
|
| 72 |
|
|
.word 0x0
|
| 73 |
2 |
csantifort |
/* ========================================================================= */
|
| 74 |
|
|
/* ========================================================================= */
|
| 75 |
|
|
|
| 76 |
|
|
|
