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 -lrt -lpthread ${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_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
  86                 kallsymopt="${kallsymopt} --absolute-percpu"
  87         fi
  88
  89         if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
  90                 kallsymopt="${kallsymopt} --base-relative"
  91         fi
  92
  93         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
  94                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
  95
  96         local afile="`basename ${2} .o`.S"
  97
  98         ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
  99         ${CC} ${aflags} -c -o ${2} ${afile}
 100 }
 101
 102 # Create map file with all symbols from ${1}
 103 # See mksymap for additional details
 104 mksysmap()
 105 {
 106         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
 107 }
 108
 109 sortextable()
 110 {
 111         ${objtree}/scripts/sortextable ${1}
 112 }
 113
 114 # Delete output files in case of error
 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 on_exit()
 128 {
 129         if [ $? -ne 0 ]; then
 130                 cleanup
 131         fi
 132 }
 133 trap on_exit EXIT
 134
 135 on_signals()
 136 {
 137         exit 1
 138 }
 139 trap on_signals HUP INT QUIT TERM
 140
 141 #
 142 #
 143 # Use "make V=1" to debug this script
 144 case "${KBUILD_VERBOSE}" in
 145 *1*)
 146         set -x
 147         ;;
 148 esac
 149
 150 if [ "$1" = "clean" ]; then
 151         cleanup
 152         exit 0
 153 fi
 154
 155 # We need access to CONFIG_ symbols
 156 case "${KCONFIG_CONFIG}" in
 157 */*)
 158         . "${KCONFIG_CONFIG}"
 159         ;;
 160 *)
 161         # Force using a file from the current directory
 162         . "./${KCONFIG_CONFIG}"
 163 esac
 164
 165 #link vmlinux.o
 166 info LD vmlinux.o
 167 modpost_link vmlinux.o
 168
 169 # modpost vmlinux.o to check for section mismatches
 170 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 171
 172 # Update version
 173 info GEN .version
 174 if [ ! -r .version ]; then
 175         rm -f .version;
 176         echo 1 >.version;
 177 else
 178         mv .version .old_version;
 179         expr 0$(cat .old_version) + 1 >.version;
 180 fi;
 181
 182 # final build of init/
 183 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init GCC_PLUGINS_CFLAGS="${GCC_PLUGINS_CFLAGS}"
 184
 185 kallsymso=""
 186 kallsyms_vmlinux=""
 187 if [ -n "${CONFIG_KALLSYMS}" ]; then
 188
 189         # kallsyms support
 190         # Generate section listing all symbols and add it into vmlinux
 191         # It's a three step process:
 192         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
 193         #     but __kallsyms is empty.
 194         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
 195         #     the right size
 196         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
 197         #     the right size, but due to the added section, some
 198         #     addresses have shifted.
 199         #     From here, we generate a correct .tmp_kallsyms2.o
 200         # 2a) We may use an extra pass as this has been necessary to
 201         #     woraround some alignment related bugs.
 202         #     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
 203         # 3)  The correct ${kallsymso} is linked into the final vmlinux.
 204         #
 205         # a)  Verify that the System.map from vmlinux matches the map from
 206         #     ${kallsymso}.
 207
 208         kallsymso=.tmp_kallsyms2.o
 209         kallsyms_vmlinux=.tmp_vmlinux2
 210
 211         # step 1
 212         vmlinux_link "" .tmp_vmlinux1
 213         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
 214
 215         # step 2
 216         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
 217         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 218
 219         # step 2a
 220         if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
 221                 kallsymso=.tmp_kallsyms3.o
 222                 kallsyms_vmlinux=.tmp_vmlinux3
 223
 224                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
 225
 226                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
 227         fi
 228 fi
 229
 230 info LD vmlinux
 231 vmlinux_link "${kallsymso}" vmlinux
 232
 233 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
 234         info SORTEX vmlinux
 235         sortextable vmlinux
 236 fi
 237
 238 info SYSMAP System.map
 239 mksysmap vmlinux System.map
 240
 241 # step a (see comment above)
 242 if [ -n "${CONFIG_KALLSYMS}" ]; then
 243         mksysmap ${kallsyms_vmlinux} .tmp_System.map
 244
 245         if ! cmp -s System.map .tmp_System.map; then
 246                 echo >&2 Inconsistent kallsyms data
 247                 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
 248                 exit 1
 249         fi
 250 fi
 251
 252 # We made a new kernel - delete old version file
 253 rm -f .old_version