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/*
* Architecture specific code used by dl-startup.c
* Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
#include <features.h>
#include <bits/arm_bx.h>
#if defined(__FDPIC__)
#if !defined(__thumb__) || defined(__thumb2__)
__asm__(
" .text\n"
" .globl _start\n"
" .type _start,%function\n"
#if defined(__thumb2__)
" .thumb_func\n"
#endif
" .align 2\n"
"_start:\n"
/* We compute the parameters for __self_reloc:
- r0 is a pointer to the loadmap (either from r8 or r7 if rtld is
lauched in standalone mode)
- r1 is a pointer to the start of .rofixup section
- r2 is a pointer to the last word of .rofixup section
__self_reloc will fix indirect addresses in .rofixup
section and will return the relocated GOT value.
*/
#if defined(__thumb2__)
" sub r4, pc, #4\n"
#else
" sub r4, pc, #8\n"
#endif
" ldr r1, .L__ROFIXUP_LIST__\n"
" add r1, r1, r4\n"
" ldr r2, .L__ROFIXUP_END__\n"
" add r2, r2, r4\n"
" movs r0, r8\n"
" it eq\n"
" moveq r0, r7\n"
" push {r7, r8, r9, r10}\n"
" bl __self_reloc;\n"
" pop {r7, r8, r9, r10}\n"
/* We compute the parameters for dl_start(). See DL_START()
macro below. The address of the user entry point is
returned in dl_main_funcdesc (on stack). */
" mov r1, r7\n"
" mov r2, r8\n"
" mov r3, r9\n"
" mov r4, sp\n"
" sub r5, sp, #8\n"
" sub sp, sp, #16\n"
" str r4, [sp, #4]\n"
" str r5, [sp, #0]\n"
" mov r9, r0\n"
/* Save r9 into r4, to preserve the GOT pointer. */
" mov r4, r9\n"
" bl _dl_start;\n"
/* Now compute parameters for entry point according to FDPIC ABI. */
" ldr r10, .L_dl_fini_gotofffuncdesc\n"
/* Save GOT value from r4. */
" add r10, r10, r4\n"
" ldr r5, [sp, #8]\n"
" ldr r9, [sp, #12]\n"
" add sp, sp, #16\n"
" bx r5\n"
".loopforever:\n"
" b .loopforever\n"
".L__ROFIXUP_LIST__:\n"
" .word __ROFIXUP_LIST__ - _start\n"
".L__ROFIXUP_END__:\n"
" .word __ROFIXUP_END__ - _start\n"
".L_dl_fini_gotofffuncdesc:\n"
" .word _dl_fini(GOTOFFFUNCDESC)\n"
" .size _start,.-_start\n"
" .previous\n"
);
#else /* !defined(__thumb__) */
#error Thumb-1 is not supported
#endif /* !defined(__thumb__) */
#else /* defined(__FDPIC__) */
#if !defined(__thumb__)
__asm__(
" .text\n"
" .globl _start\n"
" .type _start,%function\n"
" .hidden _start\n"
"_start:\n"
" @ at start time, all the args are on the stack\n"
" mov r0, sp\n"
" bl _dl_start\n"
" @ returns user entry point in r0\n"
" mov r6, r0\n"
" @ we are PIC code, so get global offset table\n"
" ldr sl, .L_GET_GOT\n"
" add sl, pc, sl\n"
".L_GOT_GOT:\n"
" @ See if we were run as a command with the executable file\n"
" @ name as an extra leading argument.\n"
" ldr r4, .L_SKIP_ARGS\n"
" ldr r4, [sl, r4]\n"
" @ get the original arg count\n"
" ldr r1, [sp]\n"
" @ subtract _dl_skip_args from it\n"
" sub r1, r1, r4\n"
" @ adjust the stack pointer to skip them\n"
" add sp, sp, r4, lsl #2\n"
" @ get the argv address\n"
" add r2, sp, #4\n"
" @ store the new argc in the new stack location\n"
" str r1, [sp]\n"
" @ compute envp\n"
" add r3, r2, r1, lsl #2\n"
" add r3, r3, #4\n"
"\n\n"
" @ load the finalizer function\n"
" ldr r0, .L_FINI_PROC\n"
" ldr r0, [sl, r0]\n"
" @ jump to the user_s entry point\n"
" " __stringify(BX(r6)) "\n"
".L_GET_GOT:\n"
" .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n"
".L_SKIP_ARGS:\n"
" .word _dl_skip_args(GOTOFF)\n"
".L_FINI_PROC:\n"
" .word _dl_fini(GOT)\n"
"\n\n"
" .size _start,.-_start\n"
".previous\n"
);
#else
__asm__(
" .text\n"
" .arm\n"
" .globl _start\n"
" .type _start,%function\n"
"_start:\n"
" @ dumb: can't persuade the linker to make the start address\n"
" @ odd, so use an arm function and change to thumb (_dl_start\n"
" @ is thumb)\n"
" adr r0, __dl_thumb_start+1\n"
" bx r0\n"
"\n\n"
" .thumb\n"
" .globl __dl_thumb_start\n"
" .thumb_func\n"
" .type __dl_thumb_start,%function\n"
"__dl_thumb_start:\n"
" @ at start time, all the args are on the stack\n"
" mov r0, sp\n"
" bl _dl_start\n"
" @ returns user entry point in r0\n"
" mov r6, r0\n"
" @ we are PIC code, so get global offset table\n"
" ldr r7, .L_GET_GOT\n"
".L_GOT_GOT:\n"
" add r7, pc\n"
" @ See if we were run as a command with the executable file\n"
" @ name as an extra leading argument.\n"
" ldr r4, .L_SKIP_ARGS\n"
" ldr r4, [r7, r4]\n"
" @ get the original arg count\n"
" ldr r1, [sp]\n"
" @ subtract _dl_skip_args from it\n"
" sub r1, r1, r4\n"
" @ adjust the stack pointer to skip them\n"
" lsl r4, r4, #2\n"
" add sp, r4\n"
" @ get the argv address\n"
" add r2, sp, #4\n"
" @ store the new argc in the new stack location\n"
" str r1, [sp]\n"
" @ compute envp\n"
" lsl r3, r1, #2\n"
" add r3, r3, r2\n"
" add r3, #4\n"
"\n\n"
" @ load the finalizer function\n"
" ldr r0, .L_FINI_PROC\n"
" ldr r0, [r7, r0]\n"
" @ jump to the user_s entry point\n"
" " __stringify(BX(r6)) "\n"
"\n\n"
".L_GET_GOT:\n"
" .word _GLOBAL_OFFSET_TABLE_ - .L_GOT_GOT - 4\n"
".L_SKIP_ARGS:\n"
" .word _dl_skip_args(GOTOFF)\n"
".L_FINI_PROC:\n"
" .word _dl_fini(GOT)\n"
"\n\n"
" .size _start,.-_start\n"
".previous\n"
);
#endif
#endif /* defined(__FDPIC__) */
/* Get a pointer to the argv array. On many platforms this can be just
* the address of the first argument, on other platforms we need to
* do something a little more subtle here. */
#define GET_ARGV(ARGVP, ARGS) ARGVP = (((unsigned long*)ARGS)+1)
/* Handle relocation of the symbols in the dynamic loader. */
static __always_inline
void PERFORM_BOOTSTRAP_RELOC(ELF_RELOC *rpnt, unsigned long *reloc_addr,
unsigned long symbol_addr, DL_LOADADDR_TYPE load_addr, Elf32_Sym *symtab)
{
switch (ELF_R_TYPE(rpnt->r_info)) {
case R_ARM_NONE:
break;
case R_ARM_ABS32:
*reloc_addr += symbol_addr;
break;
case R_ARM_PC24:
{
unsigned long addend;
long newvalue, topbits;
addend = *reloc_addr & 0x00ffffff;
if (addend & 0x00800000) addend |= 0xff000000;
newvalue = symbol_addr - (unsigned long)reloc_addr + (addend << 2);
topbits = newvalue & 0xfe000000;
if (topbits != 0xfe000000 && topbits != 0x00000000)
{
#if 0
/* Don't bother with this during ldso initilization... */
newvalue = fix_bad_pc24(reloc_addr, symbol_addr)
- (unsigned long)reloc_addr + (addend << 2);
topbits = newvalue & 0xfe000000;
if (unlikely(topbits != 0xfe000000 && topbits != 0x00000000))
{
SEND_STDERR("R_ARM_PC24 relocation out of range\n");
_dl_exit(1);
}
#else
SEND_STDERR("R_ARM_PC24 relocation out of range\n");
_dl_exit(1);
#endif
}
newvalue >>= 2;
symbol_addr = (*reloc_addr & 0xff000000) | (newvalue & 0x00ffffff);
*reloc_addr = symbol_addr;
break;
}
case R_ARM_GLOB_DAT:
case R_ARM_JUMP_SLOT:
*reloc_addr = symbol_addr;
break;
case R_ARM_RELATIVE:
*reloc_addr = DL_RELOC_ADDR(load_addr, *reloc_addr);
break;
case R_ARM_COPY:
break;
#ifdef __FDPIC__
case R_ARM_FUNCDESC_VALUE:
{
struct funcdesc_value *dst = (struct funcdesc_value *) reloc_addr;
dst->entry_point += symbol_addr;
dst->got_value = load_addr.got_value;
}
break;
#endif
default:
SEND_STDERR("Unsupported relocation type\n");
_dl_exit(1);
}
}
#ifdef __FDPIC__
#undef DL_START
#define DL_START(X) \
static void __attribute__ ((used)) \
_dl_start (Elf32_Addr dl_boot_got_pointer, \
struct elf32_fdpic_loadmap *dl_boot_progmap, \
struct elf32_fdpic_loadmap *dl_boot_ldsomap, \
Elf32_Dyn *dl_boot_ldso_dyn_pointer, \
struct funcdesc_value *dl_main_funcdesc, \
X)
/*
* Transfer control to the user's application, once the dynamic loader
* is done. We return the address of the function's entry point to
* _dl_boot, see boot1_arch.h.
*/
#define START() do { \
struct elf_resolve *exec_mod = _dl_loaded_modules; \
dl_main_funcdesc->entry_point = _dl_elf_main; \
while (exec_mod->libtype != elf_executable) \
exec_mod = exec_mod->next; \
dl_main_funcdesc->got_value = exec_mod->loadaddr.got_value; \
return; \
} while (0)
/* We use __aeabi_idiv0 in _dl_find_hash, so we need to have the raise
symbol. */
int raise(int sig)
{
_dl_exit(1);
}
#endif /* __FDPIC__ */
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