57 lines
1.7 KiB
ArmAsm
57 lines
1.7 KiB
ArmAsm
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/* Copyright (c) 2017 SiFive Inc. All rights reserved.
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This copyrighted material is made available to anyone wishing to use,
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modify, copy, or redistribute it subject to the terms and conditions
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of the FreeBSD License. This program is distributed in the hope that
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it will be useful, but WITHOUT ANY WARRANTY expressed or implied,
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including the implied warranties of MERCHANTABILITY or FITNESS FOR
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A PARTICULAR PURPOSE. A copy of this license is available at
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http://www.opensource.org/licenses.
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*/
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#include "newlib.h"
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#=========================================================================
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# crt0.S : Entry point for RISC-V user programs
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#=========================================================================
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.text
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.global _start
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.type _start, @function
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_start:
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# Initialize global pointer
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.option push
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.option norelax
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1:auipc gp, %pcrel_hi(__global_pointer$)
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addi gp, gp, %pcrel_lo(1b)
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.option pop
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# Clear the bss segment
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la a0, _edata
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la a2, _end
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sub a2, a2, a0
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li a1, 0
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call memset
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#ifdef _LITE_EXIT
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# Make reference to atexit weak to avoid unconditionally pulling in
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# support code. Refer to comments in __atexit.c for more details.
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.weak atexit
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la a0, atexit
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beqz a0, .Lweak_atexit
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.weak __libc_fini_array
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#endif
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la a0, __libc_fini_array # Register global termination functions
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call atexit # to be called upon exit
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#ifdef _LITE_EXIT
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.Lweak_atexit:
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#endif
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call __libc_init_array # Run global initialization functions
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lw a0, 0(sp) # a0 = argc
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addi a1, sp, __SIZEOF_POINTER__ # a1 = argv
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li a2, 0 # a2 = envp = NULL
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call main
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tail exit
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.size _start, .-_start
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