start.S (2958B) - Raw
1 /* Startup code for ARC. 2 Copyright (C) 2020-2025 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 In addition to the permissions in the GNU Lesser General Public 11 License, the Free Software Foundation gives you unlimited 12 permission to link the compiled version of this file with other 13 programs, and to distribute those programs without any restriction 14 coming from the use of this file. (The GNU Lesser General Public 15 License restrictions do apply in other respects; for example, they 16 cover modification of the file, and distribution when not linked 17 into another program.) 18 19 Note that people who make modified versions of this file are not 20 obligated to grant this special exception for their modified 21 versions; it is their choice whether to do so. The GNU Lesser 22 General Public License gives permission to release a modified 23 version without this exception; this exception also makes it 24 possible to release a modified version which carries forward this 25 exception. 26 27 The GNU C Library is distributed in the hope that it will be useful, 28 but WITHOUT ANY WARRANTY; without even the implied warranty of 29 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 30 Lesser General Public License for more details. 31 32 You should have received a copy of the GNU Lesser General Public 33 License along with the GNU C Library; if not, see 34 <https://www.gnu.org/licenses/>. */ 35 36 #define __ASSEMBLY__ 1 37 #include <entry.h> 38 #include <sysdep.h> 39 40 #ifndef ENTRY_POINT 41 # error ENTRY_POINT needs to be defined for ARC 42 #endif 43 44 /* When we enter this piece of code, the program stack looks like this: 45 argc argument counter (integer) 46 argv[0] program name (pointer) 47 argv[1...N] program args (pointers) 48 argv[argc-1] end of args (integer) 49 NULL 50 env[0...N] environment variables (pointers) 51 NULL. */ 52 53 ENTRY (ENTRY_POINT) 54 55 /* Needed to make gdb backtraces stop here. */ 56 .cfi_label .Ldummy 57 cfi_undefined (blink) 58 59 mov fp, 0 60 ld_s r1, [sp] /* argc. */ 61 62 mov_s r5, r0 /* rltd_fini. */ 63 add_s r2, sp, 4 /* argv. */ 64 and sp, sp, -8 65 mov r6, sp 66 67 /* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end). */ 68 69 mov_s r3, 0 /* Used to be init. */ 70 mov r4, 0 /* Used to be fini. */ 71 72 #ifdef SHARED 73 ld r0, [pcl, @main@gotpc] 74 bl __libc_start_main@plt 75 #else 76 mov_s r0, main 77 bl __libc_start_main 78 #endif 79 80 /* Should never get here. */ 81 flag 1 82 END (ENTRY_POINT) 83 84 /* Define a symbol for the first piece of initialized data. */ 85 .data 86 .globl __data_start 87 __data_start: 88 .long 0 89 .weak data_start 90 data_start = __data_start