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