/* crt0.S. C design runtime startup file.
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/* crt0.S. C design runtime startup file.
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Copyright (C) 2004, Jacob Bower
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Copyright (C) 2004, Jacob Bower
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Copyright (C) 2010, Embecosm Limited
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Copyright (C) 2010, Embecosm Limited
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Copyright (C) 2011, ORSoC AB
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Copyright (C) 2011, ORSoC AB
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Contributor Jeremy Bennett
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Contributor Jeremy Bennett
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Contributor Julius Baxter
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Contributor Julius Baxter
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This file is part of Newlib.
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This file is part of Newlib.
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The original work by Jacob Bower is provided as-is without any kind of
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The original work by Jacob Bower is provided as-is without any kind of
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warranty. Use it at your own risk!
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warranty. Use it at your own risk!
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All subsequent work is bound by version 3 of the GPL as follows.
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All subsequent work is bound by version 3 of the GPL as follows.
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This program is free software; you can redistribute it and/or modify it
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the Free
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under the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at your option)
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Software Foundation; either version 3 of the License, or (at your option)
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any later version.
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any later version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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more details.
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You should have received a copy of the GNU General Public License along
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You should have received a copy of the GNU General Public License along
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with this program. If not, see . */
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with this program. If not, see . */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/* This program is commented throughout in a fashion suitable for processing
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/* This program is commented throughout in a fashion suitable for processing
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with Doxygen. */
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with Doxygen. */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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#include "spr-defs.h"
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#include "spr-defs.h"
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/*!Macro to load a symbol's address into a register.
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/*!Macro to load a symbol's address into a register.
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@param[in] gpr General purpose register to load address into.
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@param[in] gpr General purpose register to load address into.
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@param[in] symbol Name of symbol to load. */
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@param[in] symbol Name of symbol to load. */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
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#define LOAD_SYMBOL_2_GPR(gpr,symbol) \
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.global symbol ; \
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.global symbol ; \
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l.movhi gpr, hi(symbol) ; \
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l.movhi gpr, hi(symbol) ; \
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l.ori gpr, gpr, lo(symbol)
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l.ori gpr, gpr, lo(symbol)
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/*!Macro to handle exceptions.
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/*!Macro to handle exceptions.
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Load NPC into r3, EPCR into r4
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Load NPC into r3, EPCR into r4
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*/
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*/
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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// Size of redzone + size of space required to store state
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// Size of redzone + size of space required to store state
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// This value must match that in the support library or1k_exception_handler
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// This value must match that in the support library or1k_exception_handler
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// function
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// function
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#define EXCEPTION_STACK_SIZE (128+128)
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#define EXCEPTION_STACK_SIZE (128+128)
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#define CALL_EXCEPTION_HANDLER \
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#define CALL_EXCEPTION_HANDLER \
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l.addi r1, r1, -EXCEPTION_STACK_SIZE; \
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l.addi r1, r1, -EXCEPTION_STACK_SIZE; \
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l.sw 4(r1), r3; \
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l.sw 4(r1), r3; \
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l.sw 8(r1), r4; \
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l.sw 8(r1), r4; \
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l.mfspr r3,r0,SPR_NPC; \
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l.mfspr r3,r0,SPR_NPC; \
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l.j or1k_exception_handler; \
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l.j or1k_exception_handler; \
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l.mfspr r4,r0,SPR_EPCR_BASE
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l.mfspr r4,r0,SPR_EPCR_BASE
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/*!Exception vectors */
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/*!Exception vectors */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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.section .vectors,"ax"
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.section .vectors,"ax"
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/* 0x100: RESET exception */
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/* 0x100: RESET exception */
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.org 0x100
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.org 0x100
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__reset:
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__reset:
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l.movhi r0, 0
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l.movhi r0, 0
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l.movhi r1, 0
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l.movhi r1, 0
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l.movhi r2, 0
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l.movhi r2, 0
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l.movhi r3, 0
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l.movhi r3, 0
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l.movhi r4, 0
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l.movhi r4, 0
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l.movhi r5, 0
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l.movhi r5, 0
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l.movhi r6, 0
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l.movhi r6, 0
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l.movhi r7, 0
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l.movhi r7, 0
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l.movhi r8, 0
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l.movhi r8, 0
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l.movhi r9, 0
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l.movhi r9, 0
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l.movhi r10, 0
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l.movhi r10, 0
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l.movhi r11, 0
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l.movhi r11, 0
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l.movhi r12, 0
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l.movhi r12, 0
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l.movhi r13, 0
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l.movhi r13, 0
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l.movhi r14, 0
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l.movhi r14, 0
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l.movhi r15, 0
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l.movhi r15, 0
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l.movhi r16, 0
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l.movhi r16, 0
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l.movhi r17, 0
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l.movhi r17, 0
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l.movhi r18, 0
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l.movhi r18, 0
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l.movhi r19, 0
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l.movhi r19, 0
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l.movhi r20, 0
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l.movhi r20, 0
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l.movhi r21, 0
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l.movhi r21, 0
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l.movhi r22, 0
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l.movhi r22, 0
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l.movhi r23, 0
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l.movhi r23, 0
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l.movhi r24, 0
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l.movhi r24, 0
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l.movhi r25, 0
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l.movhi r25, 0
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l.movhi r26, 0
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l.movhi r26, 0
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l.movhi r27, 0
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l.movhi r27, 0
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l.movhi r28, 0
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l.movhi r28, 0
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l.movhi r29, 0
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l.movhi r29, 0
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l.movhi r30, 0
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l.movhi r30, 0
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l.movhi r31, 0
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l.movhi r31, 0
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/* Clear status register, set supervisor mode */
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/* Clear status register, set supervisor mode */
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l.ori r1, r0, SPR_SR_SM
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l.ori r1, r0, SPR_SR_SM
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l.mtspr r0, r1, SPR_SR
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l.mtspr r0, r1, SPR_SR
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/* Clear timer mode register*/
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/* Clear timer mode register*/
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l.mtspr r0, r0, SPR_TTMR
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l.mtspr r0, r0, SPR_TTMR
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/* Jump to program initialisation code */
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/* Jump to program initialisation code */
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LOAD_SYMBOL_2_GPR(r4, _start)
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LOAD_SYMBOL_2_GPR(r4, _start)
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l.jr r4
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l.jr r4
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l.nop
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l.nop
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.org 0x200
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.org 0x200
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x300: Data Page Fault exception */
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/* 0x300: Data Page Fault exception */
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.org 0x300
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.org 0x300
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x400: Insn Page Fault exception */
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/* 0x400: Insn Page Fault exception */
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.org 0x400
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.org 0x400
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x500: Timer exception */
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/* 0x500: Timer exception */
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.org 0x500
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.org 0x500
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x600: Aligment exception */
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/* 0x600: Aligment exception */
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.org 0x600
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.org 0x600
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x700: Illegal insn exception */
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/* 0x700: Illegal insn exception */
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.org 0x700
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.org 0x700
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x800: External interrupt exception */
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/* 0x800: External interrupt exception */
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.org 0x800
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.org 0x800
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0x900: DTLB miss exception */
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/* 0x900: DTLB miss exception */
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.org 0x900
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.org 0x900
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xa00: ITLB miss exception */
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/* 0xa00: ITLB miss exception */
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.org 0xa00
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.org 0xa00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xb00: Range exception */
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/* 0xb00: Range exception */
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.org 0xb00
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.org 0xb00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xc00: Syscall exception */
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/* 0xc00: Syscall exception */
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.org 0xc00
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.org 0xc00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xd00: floating point exception */
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/* 0xd00: floating point exception */
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.org 0xd00
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.org 0xd00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xe00: Trap exception */
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/* 0xe00: Trap exception */
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.org 0xe00
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.org 0xe00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* 0xf00: Reserved exceptions */
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/* 0xf00: Reserved exceptions */
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.org 0xf00
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.org 0xf00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1000
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.org 0x1000
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1100
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.org 0x1100
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1200
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.org 0x1200
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1300
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.org 0x1300
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1400
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.org 0x1400
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1500
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.org 0x1500
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1600
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.org 0x1600
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1700
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.org 0x1700
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1800
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.org 0x1800
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1900
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.org 0x1900
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1a00
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.org 0x1a00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1b00
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.org 0x1b00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1c00
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.org 0x1c00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1d00
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.org 0x1d00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1e00
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.org 0x1e00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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.org 0x1f00
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.org 0x1f00
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CALL_EXCEPTION_HANDLER
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CALL_EXCEPTION_HANDLER
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/* Pad to the end */
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/* Pad to the end */
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.org 0x1ffc
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.org 0x1ffc
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l.nop
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l.nop
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/*!Main entry point
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/*!Main entry point
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We initialise the stack and frame pointer first, before we set up the
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We initialise the stack and frame pointer first, before we set up the
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caches, since otherwise we'll need to disable the instruction cache when
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caches, since otherwise we'll need to disable the instruction cache when
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patching the bus error vector code.
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patching the bus error vector code.
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The remaining tasks are then:
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The remaining tasks are then:
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- optionally set up instruction and/or data caches
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- optionally set up instruction and/or data caches
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- clear BSS
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- clear BSS
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- call global and static constructors
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- call global and static constructors
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- set up destructors to be called from exit
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- set up destructors to be called from exit
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- jump to the main function
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- jump to the main function
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- call exit if the main function ever returns.
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- call exit if the main function ever returns.
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- loop forever (should never get here) */
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- loop forever (should never get here) */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/* The stack grows down from the top of writable memory. */
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/* The stack grows down from the top of writable memory. */
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.section .data
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.section .data
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.global stack
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.global stack
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stack: .space 4,0
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stack: .space 4,0
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.section .text
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.section .text
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.global _start
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.global _start
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.type _start,@function
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.type _start,@function
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/* Following externs from board-specific object passed at link time */
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/* Following externs from board-specific object passed at link time */
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.extern _board_mem_base
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.extern _board_mem_base
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.extern _board_mem_size
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.extern _board_mem_size
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.extern _board_uart_base
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.extern _board_uart_base
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_start:
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_start:
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/* Initialise stack and frame pointer (set to same value) */
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/* Initialise stack and frame pointer (set to same value) */
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l.movhi r1,hi(_board_mem_base)
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l.movhi r1,hi(_board_mem_base)
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l.ori r1,r1,lo(_board_mem_base)
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l.ori r1,r1,lo(_board_mem_base)
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l.lwz r1,0(r1)
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l.lwz r1,0(r1)
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l.movhi r2,hi(_board_mem_size)
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l.movhi r2,hi(_board_mem_size)
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l.ori r2,r2,lo(_board_mem_size)
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l.ori r2,r2,lo(_board_mem_size)
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l.lwz r2,0(r2)
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l.lwz r2,0(r2)
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l.add r1,r1,r2
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l.add r1,r1,r2
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l.or r2,r1,r1
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l.or r2,r1,r1
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/* Store stack address in stack variable */
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/* Store stack address in stack variable */
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l.movhi r3,hi(stack)
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l.movhi r3,hi(stack)
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l.ori r3,r3,lo(stack)
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l.ori r3,r3,lo(stack)
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l.sw 0(r3),r1
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l.sw 0(r3),r1
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/* Initialise cache */
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/* Initialise cache */
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/* TODO - potentially make this optional for simulation targets to save
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/* TODO - potentially make this optional for simulation targets to save
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time during startup */
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time during startup */
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l.jal or1k_cache_init
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l.jal or1k_cache_init
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l.nop
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l.nop
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/* Clear BSS */
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/* Clear BSS */
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.L10: l.movhi r3,hi(__bss_start)
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.L10: l.movhi r3,hi(__bss_start)
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l.ori r3,r3,lo(__bss_start)
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l.ori r3,r3,lo(__bss_start)
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l.movhi r4,hi(end)
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l.movhi r4,hi(end)
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l.ori r4,r4,lo(end)
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l.ori r4,r4,lo(end)
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.L1: l.sw (0)(r3),r0
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.L1: l.sw (0)(r3),r0
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l.sfltu r3,r4
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l.sfltu r3,r4
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l.bf .L1
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l.bf .L1
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l.addi r3,r3,4 /* Delay slot */
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l.addi r3,r3,4 /* Delay slot */
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|
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/* Reinitialize the reentrancy structure */
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/* Reinitialize the reentrancy structure */
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l.jal __impure_init
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l.jal __impure_init
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l.nop
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l.nop
|
|
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/* Call global and static constructors */
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/* Call global and static constructors */
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l.jal __init
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l.jal __init
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l.nop
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l.nop
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|
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/* Set up destructors to be called from exit if main ever returns */
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/* Set up destructors to be called from exit if main ever returns */
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l.movhi r3,hi(__fini)
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l.movhi r3,hi(__fini)
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l.jal atexit
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l.jal atexit
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l.ori r3,r3,lo(__fini) /* Delay slot */
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l.ori r3,r3,lo(__fini) /* Delay slot */
|
|
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/* Check if UART is to be initialised */
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/* Check if UART is to be initialised */
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l.movhi r4,hi(_board_uart_base)
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l.movhi r4,hi(_board_uart_base)
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l.ori r4,r4,lo(_board_uart_base)
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l.ori r4,r4,lo(_board_uart_base)
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l.lwz r4,0(r4)
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l.lwz r4,0(r4)
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l.sfne r4,r0 /* Is base set? If not, no UART */
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l.sfne r4,r0 /* Is base set? If not, no UART */
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l.bnf .L2
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l.bnf .L2
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l.or r3,r0,r0
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l.or r3,r0,r0
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l.jal __uart_init
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l.jal __uart_init
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l.nop
|
l.nop
|
|
|
.L2:
|
.L2:
|
/* Jump to main program entry point (argc = argv = envp = 0) */
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/* Jump to main program entry point (argc = argv = envp = 0) */
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l.or r3,r0,r0
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l.or r3,r0,r0
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l.or r4,r0,r0
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l.or r4,r0,r0
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l.jal main
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l.jal main
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l.or r5,r0,r0 /* Delay slot */
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l.or r5,r0,r0 /* Delay slot */
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|
|
/* If program exits, call exit routine */
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/* If program exits, call exit routine */
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l.jal exit
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l.jal exit
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l.addi r3,r11,0 /* Delay slot */
|
l.addi r3,r11,0 /* Delay slot */
|
|
|
/* Loop forever */
|
/* Loop forever */
|
.L3: l.j .L3
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.L3: l.j .L3
|
l.nop
|
l.nop
|
|
|
.size _start, .-_start
|
.size _start, .-_start
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|
|
