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Bring in support for n64 and n32 ABIs, at least at the base.

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o Rename __start to __start_mips and change the args a little
o Create a new __start written in assembler that copes with the
  different ABIs and rewrites the args a little to make their passing
  more abi agnostic.
o Add an alias _start for __start for the Cavium toolchain (in the
  cavium port, a custom ld script is used which references _start
  instead of the traditional mips __start).
o call _init_tls() when we aren't being an a.out shared library (which
  is the only time _DYNAMIC is != NULL, I think).  We could likely
  retire support for a.out shared libraries entirely, but that will be
  in the future when I'm sure there's not some subtle reason to keep
  them around.

# Note: the reason mips starts at __start instead of _start is purely
# historical, but I didn't want to change it here and in the
# toolchain.  The Cavium build process is kind of the odd duck here,
# but it is trivial to support both, so why not...
This commit is contained in:
Warner Losh 2009-12-23 08:22:48 +00:00
parent a321ad5e62
commit 0eb9a6955c
1 changed files with 73 additions and 18 deletions
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91
lib/csu/mips/crt1.c
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@ -1,6 +1,4 @@
/*-
* Copyright 1996-1998 John D. Polstra.
* All rights reserved.
* Copyright (c) 1995 Christopher G. Demetriou
* All rights reserved.
*
@ -65,37 +63,94 @@ extern int etext;
char **environ;
const char *__progname = "";
struct ps_strings *__ps_strings;
void __gccmain(void) {}
void __main(void) {}
/* The entry function. */
void
__start(char **ap,
void (*cleanup)(void), /* from shared loader */
struct Struct_Obj_Entry *obj, /* from shared loader */
struct ps_strings *ps_strings)
{
int argc;
char **argv;
char **env;
/*
* Historically, mips has used __start for the beginning address of programs.
* However, the Cavium toolchain (and maybe others) use _start. Define both
* here. The assembler code here tries to juggle the arguments such that they
* are right for all ABIs and then calls __start_mips which is what used to
* be just plain __start, and still is on other BSD ports.
*/
argc = * (long *) ap;
argv = ap + 1;
env = ap + 2 + argc;
/* The entry function. */
__asm(" .text \n"
" .align 8 \n"
" .globl _start \n"
" _start: \n"
" .globl __start \n"
" __start: \n"
#if defined(__mips_n32) || defined(__mips_n64)
" .cpsetup $25, $24, __start\n"
#else
" .set noreorder \n"
" .cpload $25 \n"
" .set reorder \n"
#endif
" /* Get cleanup routine and main object set by rtld */\n"
" /* Note that a2 is already set to ps_string by _rtld_start */\n"
" /* move a3, a0 */\n"
" /* move t0, a1 */\n"
" /* Get argc, argv from stack */ \n"
" /* lw a0, 0(sp) */\n"
" /* move a1, sp */\n"
" /* addu a1, 4 */\n"
" \n"
" /* Stack should 8bytes aligned */\n"
" /* required by ABI to pass */\n"
" /* 64-bits arguments */\n"
" /* and sp, ~8 */\n"
" /* subu sp, sp, 20 */\n"
" /* sw t0, 16(sp) */\n"
" \n"
" move $7, $4 /* atexit */\n"
" move $8, $5 /* main_obj entry */\n"
#if defined(__mips_n64)
" ld $4, 0($29) \n"
" move $5, $29 \n"
" addu $5, 8 \n"
#else
" lw $4, 0($29) \n"
" move $5, $29 \n"
" addu $5, 4 \n"
#endif
" \n"
" and $29, 0xfffffff8 \n"
" subu $29, $29, 24 /* args slot + cleanup + 4 bytes padding */ \n"
" sw $8, 16($29) \n"
"\n"
" la $25, __start_mips \n"
" nop \n"
" j $25\n");
/* ARGSUSED */
void
__start_mips(int argc, char **argv, struct ps_strings *ps_strings,
void (*cleanup)(void), struct Struct_Obj_Entry *obj __unused)
{
char **env;
const char *s;
env = argv + argc + 1;
environ = env;
if(argc > 0 && argv[0] != NULL) {
const char *s;
__progname = argv[0];
for (s = __progname; *s != '\0'; s++)
if (*s == '/')
__progname = s + 1;
}
#ifndef NOSHARED
__ps_strings = ps_strings;
if (&_DYNAMIC != NULL)
atexit(cleanup);
#endif
else
_init_tls();
#ifdef GCRT
atexit(_mcleanup);
#endif