85 lines · c
1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */2/*3 * C Run Time support for NOLIBC4 * Copyright (C) 2023 Zhangjin Wu <falcon@tinylab.org>5 */6 7#ifndef _NOLIBC_CRT_H8#define _NOLIBC_CRT_H9 10char **environ __attribute__((weak));11const unsigned long *_auxv __attribute__((weak));12 13static void __stack_chk_init(void);14static void exit(int);15 16extern void (*const __preinit_array_start[])(int, char **, char**) __attribute__((weak));17extern void (*const __preinit_array_end[])(int, char **, char**) __attribute__((weak));18 19extern void (*const __init_array_start[])(int, char **, char**) __attribute__((weak));20extern void (*const __init_array_end[])(int, char **, char**) __attribute__((weak));21 22extern void (*const __fini_array_start[])(void) __attribute__((weak));23extern void (*const __fini_array_end[])(void) __attribute__((weak));24 25__attribute__((weak,used))26void _start_c(long *sp)27{28 long argc;29 char **argv;30 char **envp;31 int exitcode;32 void (* const *ctor_func)(int, char **, char **);33 void (* const *dtor_func)(void);34 const unsigned long *auxv;35 /* silence potential warning: conflicting types for 'main' */36 int _nolibc_main(int, char **, char **) __asm__ ("main");37 38 /* initialize stack protector */39 __stack_chk_init();40 41 /*42 * sp : argc <-- argument count, required by main()43 * argv: argv[0] <-- argument vector, required by main()44 * argv[1]45 * ...46 * argv[argc-1]47 * null48 * environ: environ[0] <-- environment variables, required by main() and getenv()49 * environ[1]50 * ...51 * null52 * _auxv: _auxv[0] <-- auxiliary vector, required by getauxval()53 * _auxv[1]54 * ...55 * null56 */57 58 /* assign argc and argv */59 argc = *sp;60 argv = (void *)(sp + 1);61 62 /* find environ */63 environ = envp = argv + argc + 1;64 65 /* find _auxv */66 for (auxv = (void *)envp; *auxv++;)67 ;68 _auxv = auxv;69 70 for (ctor_func = __preinit_array_start; ctor_func < __preinit_array_end; ctor_func++)71 (*ctor_func)(argc, argv, envp);72 for (ctor_func = __init_array_start; ctor_func < __init_array_end; ctor_func++)73 (*ctor_func)(argc, argv, envp);74 75 /* go to application */76 exitcode = _nolibc_main(argc, argv, envp);77 78 for (dtor_func = __fini_array_end; dtor_func > __fini_array_start;)79 (*--dtor_func)();80 81 exit(exitcode);82}83 84#endif /* _NOLIBC_CRT_H */85