Subversion Repositories amber

/*----------------------------------------------------------------
//                                                              //
//  start.S                                                     //
//                                                              //
//  This file is part of the Amber project                      //
//  http://www.opencores.org/project,amber                      //
//                                                              //
//  Description                                                 //
//  Assembly routines for hello-world.                          //
//  As hello-world is a stand-alone application, it needs a     //
//  simple start function written in assembly to call the       //
//  C code main() function.                                     //
//                                                              //
//  Author(s):                                                  //
//      - Conor Santifort, csantifort.amber@gmail.com           //
//                                                              //
//////////////////////////////////////////////////////////////////
//                                                              //
// Copyright (C) 2010 Authors and OPENCORES.ORG                 //
//                                                              //
// This source file may be used and distributed without         //
// restriction provided that this copyright statement is not    //
// removed from the file and that any derivative work contains  //
// the original copyright notice and the associated disclaimer. //
//                                                              //
// This source file 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.                                               //
//                                                              //
// This source 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 this source; if not, download it   //
// from http://www.opencores.org/lgpl.shtml                     //
//                                                              //
----------------------------------------------------------------*/

        .section .text
        .globl  start 
_start:               
        /* Switch to User Mode */
        /* and unset interrupt mask bits */
        mov     r0, #0x00000000
        teqp    pc, r0 
 
        @ Enable the cache
        mov     r0,  #0xffffffff
        mcr     15, 0, r0, cr3, cr0, 0   @ cacheable area
        mov     r0,  #1
        mcr     15, 0, r0, cr2, cr0, 0   @ cache enable
        
        @ initialize malloc
        ldr     r1, AdrMalloc
        str     r1, [r1]
        
        @ initialize the stack pointer
        ldr     sp, AdrStack

        @ jump to main
        .extern main
        bl      main
                
        b       _testpass
        
/* stack at top of ddr3 memory space */
AdrStack:  .word  0x8000000
AdrMalloc: .word  0x7000000


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