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Diffstat (limited to 'kernel/arch/mips/execsp.S')
| -rw-r--r-- | kernel/arch/mips/execsp.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/kernel/arch/mips/execsp.S b/kernel/arch/mips/execsp.S new file mode 100644 index 000000000000..b4f2dcfd6e2c --- /dev/null +++ b/kernel/arch/mips/execsp.S @@ -0,0 +1,118 @@ +/* $NetBSD: execsp.S,v 1.2 2025/04/27 16:49:54 riastradh 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 1.2 2025/04/27 16:49:54 riastradh Exp $") + +#include "SYS.h" + + .text + +/* + * void execsp_start(void *stackpointer@a0, void (*cleanup@a1)(void), + * void *obj_main@a2, struct ps_strings *ps_strings@a3) + * + * ELF entry point. Saves the stack pointer in startsp and defers + * to the usual csu __start routine. + */ +LEAF(execsp_start) + PIC_PROLOGUE(execsp_start) /* gp setup, sets t3 */ + + PTR_LA t1, _C_LABEL(startsp) /* load t1 := &startsp */ + NOP_L /* load hazard */ + PTR_S sp, 0(t1) /* store startsp := stack pointer */ + + PIC_TAILCALL(__start) /* gp restore, uses t3 */ +END(execsp_start) + +/* + * void execsp_ctor(void) + * + * ELF constructor. Saves the stack pointer in ctorsp and + * returns. + */ +LEAF(execsp_ctor) + PIC_PROLOGUE(execsp_ctor) /* gp setup, sets t3 */ + + PTR_LA t1, _C_LABEL(ctorsp) /* load t1 := &ctorsp */ + NOP_L /* load hazard */ + PTR_S sp, 0(t1) /* store ctorsp := stack pointer */ + + PIC_RETURN() /* gp restore, uses t3 */ +END(execsp_ctor) + + /* Make execsp_ctor a constructor. */ + .pushsection .ctors,"aw",@progbits + .p2align PTR_SCALESHIFT + PTR_WORD _C_LABEL(execsp_ctor) + .popsection + +/* + * int main(int argc@a0, char **argv@a1, ...) + * + * Main function. Saves the stack pointer in mainsp and returns + * zero. We will call execsp_main in execsp_dtor once dtorsp has + * been initialized. + */ +LEAF(main) + PIC_PROLOGUE(main) /* gp setup, sets t3 */ + + PTR_LA t1, _C_LABEL(mainsp) /* load t1 := &mainsp */ + NOP_L /* load hazard */ + PTR_S sp, 0(t1) /* store mainsp := stack pointer */ + + move v0, zero /* return 0 */ + + PIC_RETURN() /* gp restore, uses t3 */ +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. + */ +LEAF(execsp_dtor) + PIC_PROLOGUE(execsp_dtor) /* gp setup, sets t3 */ + + PTR_LA t1, _C_LABEL(dtorsp) /* load t1 := &dtorsp */ + NOP_L /* load hazard */ + PTR_S sp, 0(t1) /* store dtorsp := stack pointer */ + + PIC_TAILCALL(execsp_main) /* gp restore, uses t3 */ +END(execsp_dtor) + + /* Make execsp_ctor a destructor. */ + .pushsection .dtors,"aw",@progbits + .p2align PTR_SCALESHIFT + PTR_WORD _C_LABEL(execsp_dtor) + .popsection |