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_ARM}" ] && [ -z "${CONFIG_XIP_KERNEL}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then
  86                 kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
  87         fi
  88
  89         if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
  90                 kallsymopt="${kallsymopt} --absolute-percpu"
  91         fi
  92
  93         if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
  94                 kallsymopt="${kallsymopt} --base-relative"
  95         fi
  96
  97         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
  98                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
  99
 100         ${NM} -n ${1} | \
 101                 scripts/kallsyms ${kallsymopt} | \
 102                 ${CC} ${aflags} -c -o ${2} -x assembler-with-cpp -
 103 }
 104
 105 # Create map file with all symbols from ${1}
 106 # See mksymap for additional details
 107 mksysmap()
 108 {
 109         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
 110 }
 111
 112 sortextable()
 113 {
 114         ${objtree}/scripts/sortextable ${1}
 115 }
 116
 117 # Delete output files in case of error
 118 cleanup()
 119 {
 120         rm -f .old_version
 121         rm -f .tmp_System.map
 122         rm -f .tmp_kallsyms*
 123         rm -f .tmp_version
 124         rm -f .tmp_vmlinux*
 125         rm -f System.map
 126         rm -f vmlinux
 127         rm -f vmlinux.o
 128 }
 129
 130 on_exit()
 131 {
 132         if [ $? -ne 0 ]; then
 133                 cleanup
 134         fi
 135 }
 136 trap on_exit EXIT
 137
 138 on_signals()
 139 {
 140         exit 1
 141 }
 142 trap on_signals HUP INT QUIT TERM
 143
 144 #
 145 #
 146 # Use "make V=1" to debug this script
 147 case "${KBUILD_VERBOSE}" in
 148 *1*)
 149         set -x
 150         ;;
 151 esac
 152
 153 if [ "$1" = "clean" ]; then
 154         cleanup
 155         exit 0
 156 fi
 157
 158 # We need access to CONFIG_ symbols
 159 case "${KCONFIG_CONFIG}" in
 160 */*)
 161         . "${KCONFIG_CONFIG}"
 162         ;;
 163 *)
 164         # Force using a file from the current directory
 165         . "./${KCONFIG_CONFIG}"
 166 esac
 167
 168 #link vmlinux.o
 169 info LD vmlinux.o
 170 modpost_link vmlinux.o
 171
 172 # modpost vmlinux.o to check for section mismatches
 173 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
 174
 175 # Update version
 176 info GEN .version
 177 if [ ! -r .version ]; then
 178         rm -f .version;
 179         echo 1 >.version;
 180 else
 181         mv .version .old_version;
 182         expr 0$(cat .old_version) + 1 >.version;
 183 fi;
 184
 185 # final build of init/
 186 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
 187
 188 kallsymso=""
 189 kallsyms_vmlinux=""
 190 if [ -n "${CONFIG_KALLSYMS}" ]; then
 191
 192         # kallsyms support
 193         # Generate section listing all symbols and add it into vmlinux
 194         # It's a three step process:
 195         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
 196         #     but __kallsyms is empty.
 197         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
 198         #     the right size
 199         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
 200         #     the right size, but due to the added section, some
 201         #     addresses have shifted.
 202         #     From here, we generate a correct .tmp_kallsyms2.o
 203         # 2a) We may use an extra pass as this has been necessary to
 204         #     woraround some alignment related bugs.
 205         #     KALLSYMS_EXTRA_PASS=1 is used to trigger this.
 206         # 3)  The correct ${kallsymso} is linked into the final vmlinux.
 207         #
 208         # a)  Verify that the System.map from vmlinux matches the map from
 209         #     ${kallsymso}.
 210
 211         kallsymso=.tmp_kallsyms2.o
 212         kallsyms_vmlinux=.tmp_vmlinux2
 213
 214         # step 1
 215         vmlinux_link "" .tmp_vmlinux1
 216         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
 217
 218         # step 2
 219         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
 220         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
 221
 222         # step 2a
 223         if [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
 224                 kallsymso=.tmp_kallsyms3.o
 225                 kallsyms_vmlinux=.tmp_vmlinux3
 226
 227                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
 228
 229                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
 230         fi
 231 fi
 232
 233 info LD vmlinux
 234 vmlinux_link "${kallsymso}" vmlinux
 235
 236 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
 237         info SORTEX vmlinux
 238         sortextable vmlinux
 239 fi
 240
 241 info SYSMAP System.map
 242 mksysmap vmlinux System.map
 243
 244 # step a (see comment above)
 245 if [ -n "${CONFIG_KALLSYMS}" ]; then
 246         mksysmap ${kallsyms_vmlinux} .tmp_System.map
 247
 248         if ! cmp -s System.map .tmp_System.map; then
 249                 echo >&2 Inconsistent kallsyms data
 250                 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
 251                 exit 1
 252         fi
 253 fi
 254
 255 # We made a new kernel - delete old version file
 256 rm -f .old_version