/* Copyright (c) 2017 SiFive Inc. All rights reserved. This copyrighted material is made available to anyone wishing to use, modify, copy, or redistribute it subject to the terms and conditions of the FreeBSD License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY expressed or implied, including the implied warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A copy of this license is available at http://www.opensource.org/licenses. */ #include "newlib.h" #========================================================================= # crt0.S : Entry point for RISC-V user programs #========================================================================= .text .global _start .type _start, @function _start: # Initialize global pointer .option push .option norelax 1:auipc gp, %pcrel_hi(__global_pointer$) addi gp, gp, %pcrel_lo(1b) .option pop /* Initialize jvt CSR (reg addr: 0x0017) */ .weak __jvt_base$ lla a0, __jvt_base$ beqz a0, .Ljvt_init_end .option push .option norelax .option arch, +zicsr csrw 0x17, a0 .option pop .Ljvt_init_end: # Clear the bss segment la a0, __bss_start la a2, _end sub a2, a2, a0 li a1, 0 call memset #ifdef _LITE_EXIT # Make reference to atexit weak to avoid unconditionally pulling in # support code. Refer to comments in __atexit.c for more details. .weak atexit la a0, atexit beqz a0, .Lweak_atexit .weak __libc_fini_array #endif la a0, __libc_fini_array # Register global termination functions call atexit # to be called upon exit #ifdef _LITE_EXIT .Lweak_atexit: #endif call __libc_init_array # Run global initialization functions lw a0, 0(sp) # a0 = argc addi a1, sp, __SIZEOF_POINTER__ # a1 = argv li a2, 0 # a2 = envp = NULL call main tail exit .size _start, .-_start