107 lines
3.3 KiB
ArmAsm
107 lines
3.3 KiB
ArmAsm
/* Startup code for SH & ELF.
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Copyright (C) 1999-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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In addition to the permissions in the GNU Lesser General Public
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License, the Free Software Foundation gives you unlimited
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permission to link the compiled version of this file with other
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programs, and to distribute those programs without any restriction
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coming from the use of this file. (The GNU Lesser General Public
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License restrictions do apply in other respects; for example, they
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cover modification of the file, and distribution when not linked
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into another program.)
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Note that people who make modified versions of this file are not
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obligated to grant this special exception for their modified
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versions; it is their choice whether to do so. The GNU Lesser
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General Public License gives permission to release a modified
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version without this exception; this exception also makes it
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possible to release a modified version which carries forward this
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exception.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* This is the canonical entry point, usually the first thing in the text
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segment.
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Note that the code in the .init section has already been run.
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This includes _init and _libc_init
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At this entry point, most registers' values are unspecified, except:
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r4 Contains a function pointer to be registered with `atexit'.
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This is how the dynamic linker arranges to have DT_FINI
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functions called for shared libraries that have been loaded
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before this code runs.
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sp The stack contains the arguments and environment:
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0(sp) argc
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4(sp) argv[0]
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...
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(4*argc)(sp) NULL
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(4*(argc+1))(sp) envp[0]
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...
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NULL
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*/
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.text
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.globl _start
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.type _start,@function
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_start:
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/* Clear the frame pointer since this is the outermost frame. */
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mov #0, r14
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/* Pop argc off the stack and save a pointer to argv */
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mov.l @r15+,r5
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mov r15, r6
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/* Push the last arguments to main() onto the stack */
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mov.l r4,@-r15
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mov.l r14,@-r15 /* Used to be fini. */
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/* Set up the other arguments for main() that go in registers */
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mov.l L_main,r4
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mov #0,r7 /* Used to be init. */
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/* __libc_start_main (main, argc, argv, init, fini, rtld_fini) */
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/* Let the libc call main and exit with its return code. */
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mov.l L_libc_start_main,r1
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jsr @r1
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nop
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/* should never get here....*/
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mov.l L_abort,r1
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jsr @r1
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nop
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.align 2
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L_main:
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.long main
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L_libc_start_main:
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.long __libc_start_main
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L_abort:
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.long abort
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/* Define a symbol for the first piece of initialized data. */
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.data
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.globl __data_start
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__data_start:
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.long 0
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.weak data_start
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data_start = __data_start
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.global __fpscr_values
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__fpscr_values:
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.long 0
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.long 0x80000
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