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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [MicroBlaze/] [crt0.s] - Blame information for rev 584

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1 584 jeremybenn
###################################-*-asm*-
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#
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# Copyright (c) 2001 Xilinx, Inc.  All rights reserved.
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#
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# Xilinx, Inc. CONFIDENTIAL
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#
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# XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
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# COURTESY TO YOU.  BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
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# ONE POSSIBLE   IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
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# STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
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# IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
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# FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
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# XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
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# THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
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# ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
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# FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
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# AND FITNESS FOR A PARTICULAR PURPOSE.
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#
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# crt0.s
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#
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#       C RunTime:
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#       Used for initialization of small data
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#       anchors and stack for programs compiled using
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#       Xilinx Gnu Tools. This routine also intializes the
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#       exception and interrupt handlers
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#
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# $Id: crt0.s 2 2011-07-17 20:13:17Z filepang@gmail.com $
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#
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#######################################
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/*      Vector map (Interrupts, Exceptions, Breakpoints)                 */
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#       # 0x00 #                Jump to Start
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#       # 0x04 #                nop
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#       # 0x08 #                Imm instr for soft exception address [Hi halfword]
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#       # 0x0c #                Jump to sof Exception handler        [Lo halfword]
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#       # 0x10 #                Imm instr for interrupt address      [Hi halfword]
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#       # 0x14 #                Jump to interrupt handler            [Lo halfword]
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#       # 0x18 #                nop - Reserved for breakpoint vector
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#       # 0x1C #                nop - Reserved for breakpoint vector
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#       # 0x20 #                Imm instr for hw exception address   [Hi halfword]
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#       # 0x24 #                Jump instr to hw exception handler   [Lo halfword]
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        .globl _start
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/*      Set the exception and interrupt address vectors    */
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/*      to jump to the appropriate handlers                */
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        .align 2
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        .ent _start
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        _start:
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        bri     _start1                 # 0x00
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        nop                             # 0x04
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        nop                             # 0x08          # Reserve space for software exception vector
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        nop                             # 0x0c
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        nop                             # 0x10          # Reserve space for interrupt vector
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        nop                             # 0x14
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        nop                             # 0x18          # Reserve space for breakpoint vector
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        nop                             # 0x1c
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        nop                             # 0x18          # Reserve space for hw exception vector
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        nop                             # 0x1c
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        _start1:
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/*      Set the Small Data Anchors and the Stack pointer  */
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        la      r13, r0, _SDA_BASE_
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        la      r2, r0, _SDA2_BASE_
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        la      r1, r0, _stack-16       # 16 bytes (4 words are needed by
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                                        # crt for args and link reg )
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/*      Set the opcodes brai and imm for handlers         */
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        la      r6,r0,0xb8080000        # [opcode for brai ]
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        swi     r6,r0,0x4               # [brai opcode for reset]
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        swi     r6,r0,0xc               # [brai opcode for exception]
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        swi     r6,r0,0x14              # [brai opcode for interrupt]
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        swi     r6,r0,0x24              # [brai opcode for hw exceptions]
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        la      r6,r0,0xb0000000        # [opcode for imm ]
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        swi     r6,r0,0x0               # [imm opcode for reset]
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        swi     r6,r0,0x8               # [imm opcode for exception]
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        swi     r6,r0,0x10              # [imm opocde for interrupt]
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        swi     r6,r0,0x20              # [imm opocde for hw exceptions]
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/*      Set Reset vector        */
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        la      r6,r0,_start1
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        sw      r6,r1,r0
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        lhu     r7,r1,r0
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        shi     r7,r0, 0x2              # [imm for reset]
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        shi     r6,r0, 0x6              # [lower half for reset]
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/*      Set Software Exception Handler */
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        la      r6,r0,_exception_handler
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        sw      r6,r1,r0
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        lhu     r7,r1,r0
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        shi     r7,r0, 0xa              # [imm for exception]
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        shi     r6,r0, 0xe              # [lower half for exception ]
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/*      Set Interrupt Handler */
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        la      r6,r0,_interrupt_handler
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        sw      r6,r1,r0
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        lhu     r7,r1,r0
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        shi     r7,r0, 0x12             # [imm for exception]
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        shi     r6,r0, 0x16             # [lower half for intterupt ]
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/*      Set HW Exception Handler */
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        la      r6,r0,_hw_exception_handler
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        sw      r6,r1,r0
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        lhu     r7,r1,r0
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        shi     r7,r0, 0x22             # [imm for exception]
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        shi     r6,r0, 0x26             # [lower half for hw exception]
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/*      initialize bss sections                           */
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        brlid   r15,_crtinit
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        nop
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/*      Adjust the stack pointer                          */
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        addi    r1,r1,16
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/*      Fall through to exit                              */
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        .end _start
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/*      Use this exit function                            */
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        .globl exit                  # exit library call
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        .ent exit
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exit:
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        bri     exit
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        .end exit
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