Riscv64 csu support

Includes fixes pointed out by kettenis, jsg, naddy

diff --git a/lib/csu/riscv64/md_init.h b/lib/csu/riscv64/md_init.h
new file mode 100644 (file)
index 0000000..83d3b45
--- /dev/null
+++ b/lib/csu/riscv64/md_init.h
@@ -0,0 +1,156 @@
+/* $OpenBSD: md_init.h,v 1.1 2021/04/28 00:11:11 drahn Exp $ */
+/*
+ * Copyright (c) 2020 Dale Rahn <drahn@openbsd.org>
+ *
+ * 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.
+ */
+
+#ifdef __PIC__
+#define MD_SECT_CALL_FUNC(section, func)                               \
+       __asm (".section "#section", \"ax\"                             \n" \
+       "call " # func "@plt                                            \n" \
+"      .previous")
+#else
+#define MD_SECT_CALL_FUNC(section, func)                               \
+       __asm (".section "#section", \"ax\"                             \n" \
+       "call " # func "                                                \n" \
+"      .previous")
+#endif
+
+#define MD_SECTION_PROLOGUE(sect, entry_pt)                            \
+       __asm (                                                         \
+       ".section "#sect",\"ax\",%progbits                              \n" \
+       "       .globl " #entry_pt "                                    \n" \
+       "       .type " #entry_pt ",@function                           \n" \
+       "       .align 4                                                \n" \
+       #entry_pt":                                                     \n" \
+       "       addi    sp, sp, -16                                     \n" \
+       "       sd      ra,8(sp)                                        \n" \
+       "       sd      s0,0(sp)                                        \n" \
+       "       addi    s0, sp, 16                                      \n" \
+       "       /* fall thru */                                         \n" \
+       "       .previous")
+
+
+#define MD_SECTION_EPILOGUE(sect)                                      \
+       __asm (                                                         \
+       ".section "#sect",\"ax\",%progbits                              \n" \
+       "       ld      ra, 8(sp)                                       \n" \
+       "       ld      s0, 0(sp)                                       \n" \
+       "       addi    sp, sp, 16                                      \n" \
+       "       jr      ra                                              \n" \
+       "       .previous")
+
+
+#define        MD_CRT0_START                                                   \
+       __asm(                                                          \
+       ".text                                                          \n" \
+       "       .align  0                                               \n" \
+       "       .globl  _start                                          \n" \
+       "       .globl  __start                                         \n" \
+       "       .type   _start, @function                               \n" \
+       "       .type   __start, @function                              \n" \
+       "_start:                                                        \n" \
+       "__start:                                                       \n" \
+       "       mv      a3, a2  # cleanup                               \n" \
+       "/* Get argc/argv/envp from stack */                            \n" \
+       "       ld      a0, (sp)                                        \n" \
+       "       addi    a1, sp, 0x8                                     \n" \
+       "       slli    t0, a0, 0x3                                     \n" \
+       "       add     a2, a1, t0                                      \n" \
+       "       addi    a2, a2, 0x8                                     \n" \
+       "                                                               \n" \
+       "       addi    sp, sp, -16                                     \n" \
+       "       li      t0, 0                                           \n" \
+       "       sd      t0,(sp)                                         \n" \
+       "                                                               \n" \
+       "       j       ___start                                        \n" \
+       "       .size   _start, .-_start                                \n" \
+       "       .size   __start, .-__start                              \n" \
+       ".previous");
+
+#ifdef __PIC__
+#define        MD_RCRT0_START                                                  \
+       char **environ, *__progname;                                    \
+       __asm(                                                          \
+       ".text                                                          \n" \
+       "       .align  0                                               \n" \
+       "       .globl  _start                                          \n" \
+       "       .globl  __start                                         \n" \
+       "       .type   _start, @function                               \n" \
+       "       .type   __start, @function                              \n" \
+       "_start:                                                        \n" \
+       "__start:                                                       \n" \
+       "       mv      a0, sp                                          \n" \
+       "       mv      fp, sp                                          \n" \
+       "                                                               \n" \
+       "       addi    sp, sp, -(8+8+(16*8))                           \n" \
+       "       addi    a1, sp, 4                                       \n" \
+       "                                                               \n" \
+       "1:     auipc   a2, %pcrel_hi(_DYNAMIC)                         \n" \
+       "       addi    a2, a2, %pcrel_lo(1b)                           \n" \
+       "                                                               \n" \
+       "       call    _dl_boot_bind                                   \n" \
+       "                                                               \n" \
+       "       mv      sp, fp                                          \n" \
+       "       li      fp, 0x0                                         \n" \
+       "                                                               \n" \
+       "       li      a3, 0x0 /* cleanup */                           \n" \
+       "/* Get argc/argv/envp from stack */                            \n" \
+       "       ld      a0, (sp)                                        \n" \
+       "       addi    a1, sp, 0x0008                                  \n" \
+       "       slli    a2, a0, 0x3                                     \n" \
+       "       add     a2, a1, a2                                      \n" \
+       "       addi    a2, a2, 0x0008                                  \n" \
+       "                                                               \n" \
+       "       j       ___start                                        \n" \
+       "       .size   _start, .-_start                                \n" \
+       "       .size   __start, .-__start                              \n" \
+       "_dl_exit:                                                      \n" \
+       "       li      t0, " STR(SYS_exit) "                           \n" \
+       "       ecall                                                   \n" \
+       "       unimp                                                   \n" \
+       ".previous");
+#else /* non-pic/pie */
+#define        MD_RCRT0_START                                                  \
+       char **environ, *__progname;                                    \
+       __asm(                                                          \
+       ".text                                                          \n" \
+       "       .align  0                                               \n" \
+       "       .globl  _start                                          \n" \
+       "       .globl  __start                                         \n" \
+       "       .type   _start, @function                               \n" \
+       "       .type   __start, @function                              \n" \
+       "_start:                                                        \n" \
+       "__start:                                                       \n" \
+       "       mv      a0, sp                                          \n" \
+       "       li      fp, 0x0                                         \n" \
+       "                                                               \n" \
+       "       li      a3, 0x0 /* cleanup */                           \n" \
+       "/* Get argc/argv/envp from stack */                            \n" \
+       "       ld      a0, (sp)                                        \n" \
+       "       addi    a1, sp, 0x0008                                  \n" \
+       "       slli    a2, a0, 0x3                                     \n" \
+       "       add     a2, a1, a2                                      \n" \
+       "       addi    a2, a2, 0x0008                                  \n" \
+       "                                                               \n" \
+       "       j       ___start                                        \n" \
+       "       .size   _start, .-_start                                \n" \
+       "       .size   __start, .-__start                              \n" \
+       "_dl_exit:                                                      \n" \
+       "       li      t0, " STR(SYS_exit) "                           \n" \
+       "       ecall                                                   \n" \
+       "       unimp                                                   \n" \
+
+       ".previous");
+#endif