1/* Startup code for SH & ELF. 2 Copyright (C) 1999-2022 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/* This is the canonical entry point, usually the first thing in the text 37 segment. 38 39 Note that the code in the .init section has already been run. 40 This includes _init and _libc_init 41 42 43 At this entry point, most registers' values are unspecified, except: 44 45 r4 Contains a function pointer to be registered with `atexit'. 46 This is how the dynamic linker arranges to have DT_FINI 47 functions called for shared libraries that have been loaded 48 before this code runs. 49 50 sp The stack contains the arguments and environment: 51 0(sp) argc 52 4(sp) argv[0] 53 ... 54 (4*argc)(sp) NULL 55 (4*(argc+1))(sp) envp[0] 56 ... 57 NULL 58*/ 59 60 .text 61 .globl _start 62 .type _start,@function 63_start: 64 /* Clear the frame pointer since this is the outermost frame. */ 65 mov #0, r14 66 67 /* Pop argc off the stack and save a pointer to argv */ 68 mov.l @r15+,r5 69 mov r15, r6 70 71 /* Push the last arguments to main() onto the stack */ 72 mov.l r4,@-r15 73 mov.l r14,@-r15 /* Used to be fini. */ 74 75 /* Set up the other arguments for main() that go in registers */ 76 mov.l L_main,r4 77 mov #0,r7 /* Used to be init. */ 78 79 /* __libc_start_main (main, argc, argv, init, fini, rtld_fini) */ 80 81 /* Let the libc call main and exit with its return code. */ 82 mov.l L_libc_start_main,r1 83 jsr @r1 84 nop 85 /* should never get here....*/ 86 mov.l L_abort,r1 87 jsr @r1 88 nop 89 .align 2 90L_main: 91 .long main 92L_libc_start_main: 93 .long __libc_start_main 94L_abort: 95 .long abort 96/* Define a symbol for the first piece of initialized data. */ 97 .data 98 .globl __data_start 99__data_start: 100 .long 0 101 .weak data_start 102 data_start = __data_start 103 .global __fpscr_values 104__fpscr_values: 105 .long 0 106 .long 0x80000 107