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Diffstat (limited to 'kernel/arch/arm/execsp.S')
| -rw-r--r-- | kernel/arch/arm/execsp.S | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/kernel/arch/arm/execsp.S b/kernel/arch/arm/execsp.S new file mode 100644 index 000000000000..b02587ef2b33 --- /dev/null +++ b/kernel/arch/arm/execsp.S @@ -0,0 +1,119 @@ +/* $NetBSD: execsp.S,v 1.4 2025/05/07 16:26:47 uwe Exp $ */ + +/*- + * Copyright (c) 2025 The NetBSD Foundation, Inc. + * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``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 FOUNDATION OR CONTRIBUTORS + * 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. + */ + +#define _LOCORE + +#include <machine/asm.h> + +RCSID("$NetBSD: execsp.S,v 1.4 2025/05/07 16:26:47 uwe Exp $") + +/* + * void execsp_start(struct ps_strings *ps_strings@r0, void *obj_main@r1, + * void (*cleanup@r2)(void)) + * + * ELF entry point. Saves the stack pointer in startsp and defers + * to the usual csu __start routine. + */ +ENTRY(execsp_start) +0: GOT_INIT(r3, .Lgot.execsp_start) + mov r4, sp + GOT_GET(r5, r3, .Lstartsp) + str r4, [r5] + b PLT_SYM(_C_LABEL(__start)) + + GOT_INITSYM(.Lgot.execsp_start, 0b) +.Lstartsp: + .word GOT_SYM(startsp) +END(execsp_start) + +/* + * void execsp_ctor(void) + * + * ELF constructor. Saves the stack pointer in ctorsp and + * returns. + */ +ENTRY(execsp_ctor) +0: GOT_INIT(r0, .Lgot.execsp_ctor) + mov r1, sp + GOT_GET(r2, r0, .Lctorsp) + str r1, [r2] + RET + + GOT_INITSYM(.Lgot.execsp_ctor, 0b) +.Lctorsp: + .word GOT_SYM(ctorsp) +END(execsp_ctor) + + /* Make execsp_ctor a constructor. */ + .section .init_array,"aw",%init_array + .p2align 2 + .word _C_LABEL(execsp_ctor) + +/* + * int main(int argc@r0, char **argv@r1, ...) + * + * Main function. Saves the stack pointer in mainsp and returns + * zero. We will call execsp_main in execsp_dtor once dtorsp has + * been initialized. + */ +ENTRY(main) +0: GOT_INIT(r0, .Lgot.main) + mov r1, sp + GOT_GET(r2, r0, .Lmainsp) + str r1, [r2] + mov r0, #0 + RET + + GOT_INITSYM(.Lgot.main, 0b) +.Lmainsp: + .word GOT_SYM(mainsp) +END(main) + +/* + * void execsp_dtor(void) + * + * ELF destructor. Saves the stack pointer in dtorsp and defers + * to the C execsp_main in h_execsp.c to report the stack pointers + * back to the t_signal_and_sp parent. + */ +ENTRY(execsp_dtor) +0: GOT_INIT(r0, .Lgot.execsp_dtor) + mov r1, sp + GOT_GET(r2, r0, .Ldtorsp) + str r1, [r2] + b PLT_SYM(_C_LABEL(execsp_main)) + + GOT_INITSYM(.Lgot.execsp_dtor, 0b) +.Ldtorsp: + .word GOT_SYM(dtorsp) +END(execsp_dtor) + + /* Make execsp_ctor a destructor. */ + .section .fini_array,"aw",%fini_array + .p2align 2 + .word _C_LABEL(execsp_dtor) |