/* SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * crt0-minrt.S -- Minimal PRU startup code * * Copyright (c) 2024 Dimitar Dimitrov * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "newlib.h" .extern main .text .section .init0, "x" .global _start _start: /* Initialize stack pointer. */ ldi32 sp, _stack_top /* DATA and BSS are handled by the loader, so nothing to do here. */ /* Just in case main() tries to access argc, argv[] and envp. */ zero r14, 3 * 4 /* Call main. */ call main /* We should never reach here. */ _crt_exit: halt jmp _crt_exit /* PRU obviously has no shared libraries, but dso_handle helps to achieve better GCC test coverage. Besides, it should be free with minrt. */ .section .data .global __dso_handle .weak __dso_handle __dso_handle: .long 0