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/*
* Architecture specific code used by dl-startup.c
* Copyright (C) 2000-2005 by Erik Andersen <andersen@codepoet.org>
* Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
*
* Parts taken from glibc/sysdeps/x86_64/dl-machine.h
*/
__asm__ (
" .text\n"
" .global _start\n"
" .type _start,%function\n"
" .hidden _start\n"
"_start:\n"
" movq %rsp, %rdi\n"
" call _dl_start\n"
" # Save the user entry point address in %r12.\n"
" movq %rax, %r12\n"
" # See if we were run as a command with the executable file\n"
" # name as an extra leading argument.\n"
" movl _dl_skip_args(%rip), %eax\n"
" # Pop the original argument count.\n"
" popq %rdx\n"
" # Adjust the stack pointer to skip _dl_skip_args words.\n"
" leaq (%rsp,%rax,8), %rsp\n"
" # Subtract _dl_skip_args from argc.\n"
" subl %eax, %edx\n"
" # Push argc back on the stack.\n"
" pushq %rdx\n"
" # Pass our finalizer function to the user in %rdx, as per ELF ABI.\n"
" leaq _dl_fini(%rip), %rdx\n"
" # Jump to the user's entry point.\n"
" jmp *%r12\n"
" .size _start,.-_start\n"
" .previous\n"
);
/* 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, ElfW(Addr) *reloc_addr,
ElfW(Addr) symbol_addr, ElfW(Addr) load_addr, ElfW(Sym) *sym)
{
switch (ELF_R_TYPE(rpnt->r_info)) {
case R_X86_64_GLOB_DAT:
case R_X86_64_JUMP_SLOT:
*reloc_addr = symbol_addr + rpnt->r_addend;
break;
case R_X86_64_DTPMOD64:
*reloc_addr = 1;
break;
case R_X86_64_NONE:
case R_X86_64_DTPOFF64:
break;
case R_X86_64_TPOFF64:
*reloc_addr = sym->st_value + rpnt->r_addend - symbol_addr;
break;
/*TODO: case R_X86_64_RELATIVE:
*reloc_addr = load_addr + rpnt->r_addend;
break; */
default:
_dl_exit(1);
}
}
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