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_KALLSYMS_ALL}" ]; then
  78                 kallsymopt=--all-symbols
  79         fi
  80
  81         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
  82                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
  83
  84         ${NM} -n ${1} | \
  85                 scripts/kallsyms ${kallsymopt} | \
  86                 ${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
  87 }
  88
  89 # Create map file with all symbols from ${1}
  90 # See mksymap for additional details
  91 mksysmap()
  92 {
  93         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
  94 }
  95
  96 sortextable()
  97 {
  98         ${objtree}/scripts/sortextable ${1}
  99 }
 100
 101 # Delete output files in case of error
 102 trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
 103 cleanup()
 104 {
 105         rm -f .old_version
 106         rm -f .tmp_System.map
 107         rm -f .tmp_kallsyms*
 108         rm -f .tmp_version
 109         rm -f .tmp_vmlinux*
 110         rm -f System.map
 111         rm -f vmlinux
 112         rm -f vmlinux.o
 113 }
 114
 115 #
 116 #
 117 # Use "make V=1" to debug this script
 118 case "${KBUILD_VERBOSE}" in
 119 *1*)
 120         set -x
 121         ;;
 122 esac
 123
 124 if [ "$1" = "clean" ]; then
 125         cleanup
 126         exit 0
 127 fi
 128
 129 # We need access to CONFIG_ symbols
 130 . ./.config
 131
 132 #link vmlinux.o
 133 info LD vmlinux.o
 134 modpost_link vmlinux.o
 135
 136 # modpost vmlinux.o to check for section mismatches
 137 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 138
 139 # Update version
 140 info GEN .version
 141 if [ ! -r .version ]; then
 142         rm -f .version;
 143         echo 1 >.version;
 144 else
 145         mv .version .old_version;
 146         expr 0$(cat .old_version) + 1 >.version;
 147 fi;
 148
 149 # final build of init/
 150 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
 151
 152 kallsymso=""
 153 kallsyms_vmlinux=""
 154 if [ -n "${CONFIG_KALLSYMS}" ]; then
 155
 156         # kallsyms support
 157         # Generate section listing all symbols and add it into vmlinux
 158         # It's a three step process:
 159         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
 160         #     but __kallsyms is empty.
 161         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
 162         #     the right size
 163         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
 164         #     the right size, but due to the added section, some
 165         #     addresses have shifted.
 166         #     From here, we generate a correct .tmp_kallsyms2.o
 167         # 2a) We may use an extra pass as this has been necessary to
 168         #     woraround some alignment related bugs.
 169         #     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
 170         # 3)  The correct ${kallsymso} is linked into the final vmlinux.
 171         #
 172         # a)  Verify that the System.map from vmlinux matches the map from
 173         #     ${kallsymso}.
 174
 175         kallsymso=.tmp_kallsyms2.o
 176         kallsyms_vmlinux=.tmp_vmlinux2
 177
 178         # step 1
 179         vmlinux_link "" .tmp_vmlinux1
 180         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
 181
 182         # step 2
 183         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
 184         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 185
 186         # step 2a
 187         if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
 188                 kallsymso=.tmp_kallsyms3.o
 189                 kallsyms_vmlinux=.tmp_vmlinux3
 190
 191                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
 192
 193                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
 194         fi
 195 fi
 196
 197 info LD vmlinux
 198 vmlinux_link "${kallsymso}" vmlinux
 199
 200 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
 201         info SORTEX vmlinux
 202         sortextable vmlinux
 203 fi
 204
 205 info SYSMAP System.map
 206 mksysmap vmlinux System.map
 207
 208 # step a (see comment above)
 209 if [ -n "${CONFIG_KALLSYMS}" ]; then
 210         mksysmap ${kallsyms_vmlinux} .tmp_System.map
 211
 212         if ! cmp -s System.map .tmp_System.map; then
 213                 echo Inconsistent kallsyms data
 214                 echo echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
 215                 cleanup
 216                 exit 1
 217         fi
 218 fi
 219
 220 # We made a new kernel - delete old version file
 221 rm -f .old_version