scripts/link-vmlinux.sh

   1 #!/bin/sh
   2 #
   3 # link vmlinux
   4 #
   5 # vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and
   6 # $(KBUILD_VMLINUX_MAIN). Most are built-in.o files from top-level directories
   7 # in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
   8 # Ordering when linking is important, and $(KBUILD_VMLINUX_INIT) must be first.
   9 #
  10 # vmlinux
  11 #   ^
  12 #   |
  13 #   +-< $(KBUILD_VMLINUX_INIT)
  14 #   |   +--< init/version.o + more
  15 #   |
  16 #   +--< $(KBUILD_VMLINUX_MAIN)
  17 #   |    +--< drivers/built-in.o mm/built-in.o + more
  18 #   |
  19 #   +-< ${kallsymso} (see description in KALLSYMS section)
  20 #
  21 # vmlinux version (uname -v) cannot be updated during normal
  22 # descending-into-subdirs phase since we do not yet know if we need to
  23 # update vmlinux.
  24 # Therefore this step is delayed until just before final link of vmlinux.
  25 #
  26 # System.map is generated to document addresses of all kernel symbols
  27
  28 # Error out on error
  29 set -e
  30
  31 # Nice output in kbuild format
  32 # Will be supressed by "make -s"
  33 info()
  34 {
  35         if [ "${quiet}" != "silent_" ]; then
  36                 printf "  %-7s %s\n" ${1} ${2}
  37         fi
  38 }
  39
  40 # Link of vmlinux.o used for section mismatch analysis
  41 # ${1} output file
  42 modpost_link()
  43 {
  44         ${LD} ${LDFLAGS} -r -o ${1} ${KBUILD_VMLINUX_INIT}                   \
  45                 --start-group ${KBUILD_VMLINUX_MAIN} --end-group
  46 }
  47
  48 # Link of vmlinux
  49 # ${1} - optional extra .o files
  50 # ${2} - output file
  51 vmlinux_link()
  52 {
  53         local lds="${objtree}/${KBUILD_LDS}"
  54
  55         if [ "${SRCARCH}" != "um" ]; then
  56                 ${LD} ${LDFLAGS} ${LDFLAGS_vmlinux} -o ${2}                  \
  57                         -T ${lds} ${KBUILD_VMLINUX_INIT}                     \
  58                         --start-group ${KBUILD_VMLINUX_MAIN} --end-group ${1}
  59         else
  60                 ${CC} ${CFLAGS_vmlinux} -o ${2}                              \
  61                         -Wl,-T,${lds} ${KBUILD_VMLINUX_INIT}                 \
  62                         -Wl,--start-group                                    \
  63                                  ${KBUILD_VMLINUX_MAIN}                      \
  64                         -Wl,--end-group                                      \
  65                         -lutil ${1}
  66                 rm -f linux
  67         fi
  68 }
  69
  70
  71 # Create ${2} .o file with all symbols from the ${1} object file
  72 kallsyms()
  73 {
  74         info KSYM ${2}
  75         local kallsymopt;
  76
  77         if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
  78                 kallsymopt="${kallsymopt} --symbol-prefix=_"
  79         fi
  80
  81         if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
  82                 kallsymopt="${kallsymopt} --all-symbols"
  83         fi
  84
  85         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
  86                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
  87
  88         ${NM} -n ${1} | \
  89                 scripts/kallsyms ${kallsymopt} | \
  90                 ${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
  91 }
  92
  93 # Create map file with all symbols from ${1}
  94 # See mksymap for additional details
  95 mksysmap()
  96 {
  97         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
  98 }
  99
 100 sortextable()
 101 {
 102         ${objtree}/scripts/sortextable ${1}
 103 }
 104
 105 # Delete output files in case of error
 106 trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
 107 cleanup()
 108 {
 109         rm -f .old_version
 110         rm -f .tmp_System.map
 111         rm -f .tmp_kallsyms*
 112         rm -f .tmp_version
 113         rm -f .tmp_vmlinux*
 114         rm -f System.map
 115         rm -f vmlinux
 116         rm -f vmlinux.o
 117 }
 118
 119 #
 120 #
 121 # Use "make V=1" to debug this script
 122 case "${KBUILD_VERBOSE}" in
 123 *1*)
 124         set -x
 125         ;;
 126 esac
 127
 128 if [ "$1" = "clean" ]; then
 129         cleanup
 130         exit 0
 131 fi
 132
 133 # We need access to CONFIG_ symbols
 134 case "${KCONFIG_CONFIG}" in
 135 */*)
 136         . "${KCONFIG_CONFIG}"
 137         ;;
 138 *)
 139         # Force using a file from the current directory
 140         . "./${KCONFIG_CONFIG}"
 141 esac
 142
 143 #link vmlinux.o
 144 info LD vmlinux.o
 145 modpost_link vmlinux.o
 146
 147 # modpost vmlinux.o to check for section mismatches
 148 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 149
 150 # Update version
 151 info GEN .version
 152 if [ ! -r .version ]; then
 153         rm -f .version;
 154         echo 1 >.version;
 155 else
 156         mv .version .old_version;
 157         expr 0$(cat .old_version) + 1 >.version;
 158 fi;
 159
 160 # final build of init/
 161 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
 162
 163 kallsymso=""
 164 kallsyms_vmlinux=""
 165 if [ -n "${CONFIG_KALLSYMS}" ]; then
 166
 167         # kallsyms support
 168         # Generate section listing all symbols and add it into vmlinux
 169         # It's a three step process:
 170         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
 171         #     but __kallsyms is empty.
 172         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
 173         #     the right size
 174         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
 175         #     the right size, but due to the added section, some
 176         #     addresses have shifted.
 177         #     From here, we generate a correct .tmp_kallsyms2.o
 178         # 2a) We may use an extra pass as this has been necessary to
 179         #     woraround some alignment related bugs.
 180         #     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
 181         # 3)  The correct ${kallsymso} is linked into the final vmlinux.
 182         #
 183         # a)  Verify that the System.map from vmlinux matches the map from
 184         #     ${kallsymso}.
 185
 186         kallsymso=.tmp_kallsyms2.o
 187         kallsyms_vmlinux=.tmp_vmlinux2
 188
 189         # step 1
 190         vmlinux_link "" .tmp_vmlinux1
 191         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
 192
 193         # step 2
 194         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
 195         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 196
 197         # step 2a
 198         if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
 199                 kallsymso=.tmp_kallsyms3.o
 200                 kallsyms_vmlinux=.tmp_vmlinux3
 201
 202                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
 203
 204                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
 205         fi
 206 fi
 207
 208 info LD vmlinux
 209 vmlinux_link "${kallsymso}" vmlinux
 210
 211 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
 212         info SORTEX vmlinux
 213         sortextable vmlinux
 214 fi
 215
 216 info SYSMAP System.map
 217 mksysmap vmlinux System.map
 218
 219 # step a (see comment above)
 220 if [ -n "${CONFIG_KALLSYMS}" ]; then
 221         mksysmap ${kallsyms_vmlinux} .tmp_System.map
 222
 223         if ! cmp -s System.map .tmp_System.map; then
 224                 echo >&2 Inconsistent kallsyms data
 225                 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
 226                 cleanup
 227                 exit 1
 228         fi
 229 fi
 230
 231 # We made a new kernel - delete old version file
 232 rm -f .old_version