3 # Copyright © 2008 IBM Corporation
5 # This program is free software; you can redistribute it and/or
6 # modify it under the terms of the GNU General Public License
7 # as published by the Free Software Foundation; either version
8 # 2 of the License, or (at your option) any later version.
10 # This script checks prom_init.o to see what external symbols it
11 # is using, if it finds symbols not in the whitelist it returns
12 # an error. The point of this is to discourage people from
13 # intentionally or accidentally adding new code to prom_init.c
14 # which has side effects on other parts of the kernel.
16 # If you really need to reference something from prom_init.o add
17 # it to the list below:
19 WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
20 _end enter_prom memcpy memset reloc_offset __secondary_hold
21 __secondary_hold_acknowledge __secondary_hold_spinloop __start
22 strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
23 reloc_got2 kernstart_addr memstart_addr linux_banner _stext
24 __prom_init_toc_start __prom_init_toc_end btext_setup_display TOC."
31 function check_section()
35 size=$(objdump -h -j $section $file 2>/dev/null | awk "\$2 == \"$section\" {print \$3}")
37 if [ $size -ne 0 ]; then
39 echo "Error: Section $section not empty in prom_init.c" >&2
43 for UNDEF in $($NM -u $OBJ | awk '{print $2}')
45 # On 64-bit nm gives us the function descriptors, which have
46 # a leading . on the name, so strip it off here.
49 if [ $KBUILD_VERBOSE ]; then
50 if [ $KBUILD_VERBOSE -ne 0 ]; then
51 echo "Checking prom_init.o symbol '$UNDEF'"
56 for WHITE in $WHITELIST
58 if [ "$UNDEF" = "$WHITE" ]; then
64 # ignore register save/restore funcitons
66 _restgpr_*|_restgpr0_*|_rest32gpr_*)
69 _savegpr_*|_savegpr0_*|_save32gpr_*)
74 if [ $OK -eq 0 ]; then
76 echo "Error: External symbol '$UNDEF' referenced" \
77 "from prom_init.c" >&2
81 check_section $OBJ .data
82 check_section $OBJ .bss
83 check_section $OBJ .init.data