1#!/bin/sh 2# SPDX-License-Identifier: GPL-2.0 3# 4# link vmlinux 5# 6# vmlinux is linked from the objects selected by $(KBUILD_VMLINUX_INIT) and 7# $(KBUILD_VMLINUX_MAIN) and $(KBUILD_VMLINUX_LIBS). Most are built-in.a files 8# from top-level directories in the kernel tree, others are specified in 9# arch/$(ARCH)/Makefile. Ordering when linking is important, and 10# $(KBUILD_VMLINUX_INIT) must be first. $(KBUILD_VMLINUX_LIBS) are archives 11# which are linked conditionally (not within --whole-archive), and do not 12# require symbol indexes added. 13# 14# vmlinux 15# ^ 16# | 17# +-< $(KBUILD_VMLINUX_INIT) 18# | +--< init/version.o + more 19# | 20# +--< $(KBUILD_VMLINUX_MAIN) 21# | +--< drivers/built-in.a mm/built-in.a + more 22# | 23# +--< $(KBUILD_VMLINUX_LIBS) 24# | +--< lib/lib.a + more 25# | 26# +-< ${kallsymso} (see description in KALLSYMS section) 27# 28# vmlinux version (uname -v) cannot be updated during normal 29# descending-into-subdirs phase since we do not yet know if we need to 30# update vmlinux. 31# Therefore this step is delayed until just before final link of vmlinux. 32# 33# System.map is generated to document addresses of all kernel symbols 34 35# Error out on error 36set -e 37 38# Nice output in kbuild format 39# Will be supressed by "make -s" 40info() 41{ 42 if [ "${quiet}" != "silent_" ]; then 43 printf " %-7s %s\n" ${1} ${2} 44 fi 45} 46 47# Thin archive build here makes a final archive with symbol table and indexes 48# from vmlinux objects INIT and MAIN, which can be used as input to linker. 49# KBUILD_VMLINUX_LIBS archives should already have symbol table and indexes 50# added. 51# 52# Traditional incremental style of link does not require this step 53# 54# built-in.a output file 55# 56archive_builtin() 57{ 58 info AR built-in.a 59 rm -f built-in.a; 60 ${AR} rcsTP${KBUILD_ARFLAGS} built-in.a \ 61 ${KBUILD_VMLINUX_INIT} \ 62 ${KBUILD_VMLINUX_MAIN} 63} 64 65# Link of vmlinux.o used for section mismatch analysis 66# ${1} output file 67modpost_link() 68{ 69 local objects 70 71 objects="--whole-archive \ 72 built-in.a \ 73 --no-whole-archive \ 74 --start-group \ 75 ${KBUILD_VMLINUX_LIBS} \ 76 --end-group" 77 78 ${LD} ${KBUILD_LDFLAGS} -r -o ${1} ${objects} 79} 80 81# Link of vmlinux 82# ${1} - optional extra .o files 83# ${2} - output file 84vmlinux_link() 85{ 86 local lds="${objtree}/${KBUILD_LDS}" 87 local objects 88 89 if [ "${SRCARCH}" != "um" ]; then 90 objects="--whole-archive \ 91 built-in.a \ 92 --no-whole-archive \ 93 --start-group \ 94 ${KBUILD_VMLINUX_LIBS} \ 95 --end-group \ 96 ${1}" 97 98 ${LD} ${KBUILD_LDFLAGS} ${LDFLAGS_vmlinux} -o ${2} \ 99 -T ${lds} ${objects} 100 else 101 objects="-Wl,--whole-archive \ 102 built-in.a \ 103 -Wl,--no-whole-archive \ 104 -Wl,--start-group \ 105 ${KBUILD_VMLINUX_LIBS} \ 106 -Wl,--end-group \ 107 ${1}" 108 109 ${CC} ${CFLAGS_vmlinux} -o ${2} \ 110 -Wl,-T,${lds} \ 111 ${objects} \ 112 -lutil -lrt -lpthread 113 rm -f linux 114 fi 115} 116 117 118# Create ${2} .o file with all symbols from the ${1} object file 119kallsyms() 120{ 121 info KSYM ${2} 122 local kallsymopt; 123 124 if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then 125 kallsymopt="${kallsymopt} --all-symbols" 126 fi 127 128 if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then 129 kallsymopt="${kallsymopt} --absolute-percpu" 130 fi 131 132 if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then 133 kallsymopt="${kallsymopt} --base-relative" 134 fi 135 136 local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \ 137 ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}" 138 139 local afile="`basename ${2} .o`.S" 140 141 ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile} 142 ${CC} ${aflags} -c -o ${2} ${afile} 143} 144 145# Create map file with all symbols from ${1} 146# See mksymap for additional details 147mksysmap() 148{ 149 ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2} 150} 151 152sortextable() 153{ 154 ${objtree}/scripts/sortextable ${1} 155} 156 157# Delete output files in case of error 158cleanup() 159{ 160 rm -f .tmp_System.map 161 rm -f .tmp_kallsyms* 162 rm -f .tmp_vmlinux* 163 rm -f built-in.a 164 rm -f System.map 165 rm -f vmlinux 166 rm -f vmlinux.o 167} 168 169on_exit() 170{ 171 if [ $? -ne 0 ]; then 172 cleanup 173 fi 174} 175trap on_exit EXIT 176 177on_signals() 178{ 179 exit 1 180} 181trap on_signals HUP INT QUIT TERM 182 183# 184# 185# Use "make V=1" to debug this script 186case "${KBUILD_VERBOSE}" in 187*1*) 188 set -x 189 ;; 190esac 191 192if [ "$1" = "clean" ]; then 193 cleanup 194 exit 0 195fi 196 197# We need access to CONFIG_ symbols 198case "${KCONFIG_CONFIG}" in 199*/*) 200 . "${KCONFIG_CONFIG}" 201 ;; 202*) 203 # Force using a file from the current directory 204 . "./${KCONFIG_CONFIG}" 205esac 206 207# Update version 208info GEN .version 209if [ -r .version ]; then 210 VERSION=$(expr 0$(cat .version) + 1) 211 echo $VERSION > .version 212else 213 rm -f .version 214 echo 1 > .version 215fi; 216 217# final build of init/ 218${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init 219 220archive_builtin 221 222#link vmlinux.o 223info LD vmlinux.o 224modpost_link vmlinux.o 225 226# modpost vmlinux.o to check for section mismatches 227${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o 228 229kallsymso="" 230kallsyms_vmlinux="" 231if [ -n "${CONFIG_KALLSYMS}" ]; then 232 233 # kallsyms support 234 # Generate section listing all symbols and add it into vmlinux 235 # It's a three step process: 236 # 1) Link .tmp_vmlinux1 so it has all symbols and sections, 237 # but __kallsyms is empty. 238 # Running kallsyms on that gives us .tmp_kallsyms1.o with 239 # the right size 240 # 2) Link .tmp_vmlinux2 so it now has a __kallsyms section of 241 # the right size, but due to the added section, some 242 # addresses have shifted. 243 # From here, we generate a correct .tmp_kallsyms2.o 244 # 3) That link may have expanded the kernel image enough that 245 # more linker branch stubs / trampolines had to be added, which 246 # introduces new names, which further expands kallsyms. Do another 247 # pass if that is the case. In theory it's possible this results 248 # in even more stubs, but unlikely. 249 # KALLSYMS_EXTRA_PASS=1 may also used to debug or work around 250 # other bugs. 251 # 4) The correct ${kallsymso} is linked into the final vmlinux. 252 # 253 # a) Verify that the System.map from vmlinux matches the map from 254 # ${kallsymso}. 255 256 kallsymso=.tmp_kallsyms2.o 257 kallsyms_vmlinux=.tmp_vmlinux2 258 259 # step 1 260 vmlinux_link "" .tmp_vmlinux1 261 kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o 262 263 # step 2 264 vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2 265 kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o 266 267 # step 3 268 size1=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms1.o) 269 size2=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" .tmp_kallsyms2.o) 270 271 if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then 272 kallsymso=.tmp_kallsyms3.o 273 kallsyms_vmlinux=.tmp_vmlinux3 274 275 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3 276 277 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o 278 fi 279fi 280 281info LD vmlinux 282vmlinux_link "${kallsymso}" vmlinux 283 284if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then 285 info SORTEX vmlinux 286 sortextable vmlinux 287fi 288 289info SYSMAP System.map 290mksysmap vmlinux System.map 291 292# step a (see comment above) 293if [ -n "${CONFIG_KALLSYMS}" ]; then 294 mksysmap ${kallsyms_vmlinux} .tmp_System.map 295 296 if ! cmp -s System.map .tmp_System.map; then 297 echo >&2 Inconsistent kallsyms data 298 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround 299 exit 1 300 fi 301fi 302