/*      $OpenBSD: md_init.h,v 1.10 2023/11/18 16:26:16 deraadt Exp $    */

/*
 * Copyright (c) 2012 Miodrag Vallat.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#define MD_SECT_CALL_FUNC(section, func) __asm (                        \
        "\t.section\t" #section ",\"ax\",@progbits\n"                   \
        "\tbsr\t" #func "\n"                                    \
        "\t.previous")

#define MD_SECTION_PROLOGUE(section, entry) __asm (                     \
        "\t.section\t" #section ",\"ax\",@progbits\n"                   \
        "\t.globl\t" #entry "\n"                                        \
        "\t.type\t" #entry ",@function\n"                               \
        "\t.align\t2\n"                                                 \
        #entry ":\n"                                                    \
        "\tsubu\t%r31, %r31, 16\n"                                      \
        "\tst\t%r1, %r31, 0\n"                                          \
        "\t.previous")

#define MD_SECTION_EPILOGUE(section) __asm(                             \
        "\t.section\t" #section ",\"ax\",@progbits\n"                   \
        "\tld\t%r1, %r31, 0\n"                                          \
        "\tjmp.n\t%r1\n"                                                \
        "\taddu\t%r31, %r31, 16\n"                                      \
        "\t.previous")

/*
 * When a program begins, r31 points to a structure passed by the kernel.
 *
 * This structure contains argc, the argv[] NULL-terminated array, and
 * the envp[] NULL-terminated array.
 *
 * Our start code starts with two nops because execution may skip up to
 * two instructions; see setregs() in the kernel for details.
 *
 * The definitions of environ and __progname prevent the creation
 * of COPY relocations for WEAK symbols.
 */
#define MD_CRT0_START                                   \
        char **environ, *__progname;                    \
        __asm(                                          \
        "       .text                                   \n" \
        "       .align 3                                \n" \
        "       .globl __start                          \n" \
        "       .globl _start                           \n" \
        "__start:                                       \n" \
        "_start:                                        \n" \
        "       or      %r0, %r0, %r0                   \n" \
        "       or      %r0, %r0, %r0                   \n" \
        "       ld      %r2, %r31, 0    /* argc */      \n" \
        "       addu    %r3, %r31, 4    /* argv */      \n" \
        "       lda     %r4, %r3[%r2]                   \n" \
        "       br.n    ___start                        \n" \
        "        addu   %r4, %r4, 4                     \n" \
        "        /* envp = argv + argc + 1 */           \n" \
        "       .previous");

#define MD_RCRT0_START                                  \
        __asm(                                          \
        "       .text                                   \n" \
        "       .align 3                                \n" \
        "       .globl __start                          \n" \
        "       .globl _start                           \n" \
        "__start:                                       \n" \
        "_start:                                        \n" \
        "       or      %r0, %r0, %r0                   \n" \
        "       or      %r0, %r0, %r0                   \n" \
        \
        "       or      %r2, %r31, 0                    \n" \
        "       subu    %r31, %r31, 4*16                \n" \
        "       or      %r3, %r31, 0                    \n" \
        "       bsr     1f                              \n" \
        "       bsr     _DYNAMIC#plt                    \n" \
        "1:     ld      %r6, %r1, 0                     \n" \
        "       mak     %r5, %r6, 26<2>                 \n" \
        "       addu    %r4, %r5, %r1                   \n" \
        "       bsr     _dl_boot_bind#plt               \n" \
        "       addu    %r31, %r31, 4*16                \n" \
        \
        "       ld      %r2, %r31, 0    /* argc */      \n" \
        "       addu    %r3, %r31, 4    /* argv */      \n" \
        "       lda     %r4, %r3[%r2]                   \n" \
        "       or      %r5, %r0, %r0   /* cleanup */   \n" \
        "       br.n    ___start                        \n" \
        "        addu   %r4, %r4, 4                     \n" \
        "        /* envp = argv + argc + 1 */           \n" \
        \
        "_csu_abort:                                    \n" \
        "       tb0     0, %r0, 130 /* breakpoint */    \n" \
        "       .previous");