2 * arch/um/kernel/elf_aux.c
4 * Scan the Elf auxiliary vector provided by the host to extract
5 * information about vsyscall-page, etc.
7 * Copyright (C) 2004 Fujitsu Siemens Computers GmbH
8 * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
16 #if ELF_CLASS == ELFCLASS32
17 typedef Elf32_auxv_t elf_auxv_t
;
19 typedef Elf64_auxv_t elf_auxv_t
;
22 char * elf_aux_platform
;
25 unsigned long vsyscall_ehdr
;
26 unsigned long vsyscall_end
;
28 unsigned long __kernel_vsyscall
;
30 __init
void scan_elf_aux( char **envp
)
35 while ( *envp
++ != NULL
) ;
37 for ( auxv
= (elf_auxv_t
*)envp
; auxv
->a_type
!= AT_NULL
; auxv
++) {
38 switch ( auxv
->a_type
) {
40 __kernel_vsyscall
= auxv
->a_un
.a_val
;
43 vsyscall_ehdr
= auxv
->a_un
.a_val
;
46 elf_aux_hwcap
= auxv
->a_un
.a_val
;
49 /* elf.h removed the pointer elements from
50 * a_un, so we have to use a_val, which is
53 elf_aux_platform
= (char *) auxv
->a_un
.a_val
;
56 page_size
= auxv
->a_un
.a_val
;
60 if ( ! __kernel_vsyscall
|| ! vsyscall_ehdr
||
61 ! elf_aux_hwcap
|| ! elf_aux_platform
||
62 ! page_size
|| (vsyscall_ehdr
% page_size
) ) {
63 __kernel_vsyscall
= 0;
66 elf_aux_platform
= "i586";
69 vsyscall_end
= vsyscall_ehdr
+ page_size
;