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="${kallsymopt} --all-symbols"
  83         fi
  84
  85         if [ -n "${CONFIG_ARM}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
  86                 kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
  87         fi
  88
  89         if [ -n "${CONFIG_X86_64}" ]; then
  90                 kallsymopt="${kallsymopt} --absolute-percpu"
  91         fi
  92
  93         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
  94                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
  95
  96         ${NM} -n ${1} | \
  97                 scripts/kallsyms ${kallsymopt} | \
  98                 ${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
  99 }
 100
 101 # Create map file with all symbols from ${1}
 102 # See mksymap for additional details
 103 mksysmap()
 104 {
 105         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
 106 }
 107
 108 sortextable()
 109 {
 110         ${objtree}/scripts/sortextable ${1}
 111 }
 112
 113 # Delete output files in case of error
 114 trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
 115 cleanup()
 116 {
 117         rm -f .old_version
 118         rm -f .tmp_System.map
 119         rm -f .tmp_kallsyms*
 120         rm -f .tmp_version
 121         rm -f .tmp_vmlinux*
 122         rm -f System.map
 123         rm -f vmlinux
 124         rm -f vmlinux.o
 125 }
 126
 127 #
 128 #
 129 # Use "make V=1" to debug this script
 130 case "${KBUILD_VERBOSE}" in
 131 *1*)
 132         set -x
 133         ;;
 134 esac
 135
 136 if [ "$1" = "clean" ]; then
 137         cleanup
 138         exit 0
 139 fi
 140
 141 # We need access to CONFIG_ symbols
 142 case "${KCONFIG_CONFIG}" in
 143 */*)
 144         . "${KCONFIG_CONFIG}"
 145         ;;
 146 *)
 147         # Force using a file from the current directory
 148         . "./${KCONFIG_CONFIG}"
 149 esac
 150
 151 #link vmlinux.o
 152 info LD vmlinux.o
 153 modpost_link vmlinux.o
 154
 155 # modpost vmlinux.o to check for section mismatches
 156 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 157
 158 # Update version
 159 info GEN .version
 160 if [ ! -r .version ]; then
 161         rm -f .version;
 162         echo 1 >.version;
 163 else
 164         mv .version .old_version;
 165         expr 0$(cat .old_version) + 1 >.version;
 166 fi;
 167
 168 # final build of init/
 169 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
 170
 171 kallsymso=""
 172 kallsyms_vmlinux=""
 173 if [ -n "${CONFIG_KALLSYMS}" ]; then
 174
 175         # kallsyms support
 176         # Generate section listing all symbols and add it into vmlinux
 177         # It's a three step process:
 178         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
 179         #     but __kallsyms is empty.
 180         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
 181         #     the right size
 182         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
 183         #     the right size, but due to the added section, some
 184         #     addresses have shifted.
 185         #     From here, we generate a correct .tmp_kallsyms2.o
 186         # 2a) We may use an extra pass as this has been necessary to
 187         #     woraround some alignment related bugs.
 188         #     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
 189         # 3)  The correct ${kallsymso} is linked into the final vmlinux.
 190         #
 191         # a)  Verify that the System.map from vmlinux matches the map from
 192         #     ${kallsymso}.
 193
 194         kallsymso=.tmp_kallsyms2.o
 195         kallsyms_vmlinux=.tmp_vmlinux2
 196
 197         # step 1
 198         vmlinux_link "" .tmp_vmlinux1
 199         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
 200
 201         # step 2
 202         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
 203         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 204
 205         # step 2a
 206         if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
 207                 kallsymso=.tmp_kallsyms3.o
 208                 kallsyms_vmlinux=.tmp_vmlinux3
 209
 210                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
 211
 212                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
 213         fi
 214 fi
 215
 216 info LD vmlinux
 217 vmlinux_link "${kallsymso}" vmlinux
 218
 219 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
 220         info SORTEX vmlinux
 221         sortextable vmlinux
 222 fi
 223
 224 info SYSMAP System.map
 225 mksysmap vmlinux System.map
 226
 227 # step a (see comment above)
 228 if [ -n "${CONFIG_KALLSYMS}" ]; then
 229         mksysmap ${kallsyms_vmlinux} .tmp_System.map
 230
 231         if ! cmp -s System.map .tmp_System.map; then
 232                 echo >&2 Inconsistent kallsyms data
 233                 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
 234                 cleanup
 235                 exit 1
 236         fi
 237 fi
 238
 239 # We made a new kernel - delete old version file
 240 rm -f .old_version