kopia lustrzana https://github.com/micropython/micropython
71 wiersze
2.6 KiB
ArmAsm
71 wiersze
2.6 KiB
ArmAsm
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2023 Alessandro Gatti
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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.section .start
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.option norvc /* Do not emit compressed instructions. */
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.type start, @function
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.global start
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start:
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.cfi_startproc
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.option push
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.option norelax
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la gp, _global_pointer /* Load global pointer register. */
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.option pop
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csrw satp, zero /* Disable supervisor mode. */
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/* Fill stack with a canary value. */
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li t0, 0x12345678 /* Load upper canary value. */
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la t1, _sstack /* Load stack area start address. */
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la t2, _estack /* Load stack area end address. */
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1:
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sw t0, (t1) /* Write canary. */
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addi t1, t1, 4 /* Next word. */
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bltu t1, t2, 1b /* Loop until stack is filled. */
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la sp, _estack /* Load stack pointer. */
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/* Clear BSS area. */
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la t1, _sbss /* Load BSS area start address. */
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la t2, _ebss /* Load BSS area end address. */
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1:
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sw zero, (t1) /* Clear word. */
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addi t1, t1, 4 /* Next word. */
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bltu t1, t2, 1b /* Loop until BSS is cleared. */
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/* Set program counter. */
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la t0, _entry_point /* Load program counter address. */
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csrw mepc, t0 /* Store it into machine exception PC. */
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tail _entry_point /* Jump to entry point. */
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.cfi_endproc
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.end
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