kbuild: rename built-in.o to built-in.a
[muen/linux.git] / scripts / link-vmlinux.sh
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 #   +-< ${kallsymso} (see description in KALLSYMS section)
27 #
28 # vmlinux version (uname -v) cannot be updated during normal
29 # descending-into-subdirs phase since we do not yet know if we need to
30 # update vmlinux.
31 # Therefore this step is delayed until just before final link of vmlinux.
32 #
33 # System.map is generated to document addresses of all kernel symbols
34
35 # Error out on error
36 set -e
37
38 # Nice output in kbuild format
39 # Will be supressed by "make -s"
40 info()
41 {
42         if [ "${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 #
56 archive_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
67 modpost_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} ${LDFLAGS} -r -o ${1} ${objects}
79 }
80
81 # Link of vmlinux
82 # ${1} - optional extra .o files
83 # ${2} - output file
84 vmlinux_link()
85 {
86         local lds="${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} ${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
119 kallsyms()
120 {
121         info KSYM ${2}
122         local kallsymopt;
123
124         if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
125                 kallsymopt="${kallsymopt} --symbol-prefix=_"
126         fi
127
128         if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
129                 kallsymopt="${kallsymopt} --all-symbols"
130         fi
131
132         if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
133                 kallsymopt="${kallsymopt} --absolute-percpu"
134         fi
135
136         if [ -n "${CONFIG_KALLSYMS_BASE_RELATIVE}" ]; then
137                 kallsymopt="${kallsymopt} --base-relative"
138         fi
139
140         local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
141                       ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
142
143         local afile="`basename ${2} .o`.S"
144
145         ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
146         ${CC} ${aflags} -c -o ${2} ${afile}
147 }
148
149 # Create map file with all symbols from ${1}
150 # See mksymap for additional details
151 mksysmap()
152 {
153         ${CONFIG_SHELL} "${srctree}/scripts/mksysmap" ${1} ${2}
154 }
155
156 sortextable()
157 {
158         ${objtree}/scripts/sortextable ${1}
159 }
160
161 # Delete output files in case of error
162 cleanup()
163 {
164         rm -f .tmp_System.map
165         rm -f .tmp_kallsyms*
166         rm -f .tmp_vmlinux*
167         rm -f built-in.a
168         rm -f System.map
169         rm -f vmlinux
170         rm -f vmlinux.o
171 }
172
173 on_exit()
174 {
175         if [ $? -ne 0 ]; then
176                 cleanup
177         fi
178 }
179 trap on_exit EXIT
180
181 on_signals()
182 {
183         exit 1
184 }
185 trap on_signals HUP INT QUIT TERM
186
187 #
188 #
189 # Use "make V=1" to debug this script
190 case "${KBUILD_VERBOSE}" in
191 *1*)
192         set -x
193         ;;
194 esac
195
196 if [ "$1" = "clean" ]; then
197         cleanup
198         exit 0
199 fi
200
201 # We need access to CONFIG_ symbols
202 case "${KCONFIG_CONFIG}" in
203 */*)
204         . "${KCONFIG_CONFIG}"
205         ;;
206 *)
207         # Force using a file from the current directory
208         . "./${KCONFIG_CONFIG}"
209 esac
210
211 # Update version
212 info GEN .version
213 if [ -r .version ]; then
214         VERSION=$(expr 0$(cat .version) + 1)
215         echo $VERSION > .version
216 else
217         rm -f .version
218         echo 1 > .version
219 fi;
220
221 # final build of init/
222 ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init
223
224 archive_builtin
225
226 #link vmlinux.o
227 info LD vmlinux.o
228 modpost_link vmlinux.o
229
230 # modpost vmlinux.o to check for section mismatches
231 ${MAKE} -f "${srctree}/scripts/Makefile.modpost" vmlinux.o
232
233 kallsymso=""
234 kallsyms_vmlinux=""
235 if [ -n "${CONFIG_KALLSYMS}" ]; then
236
237         # kallsyms support
238         # Generate section listing all symbols and add it into vmlinux
239         # It's a three step process:
240         # 1)  Link .tmp_vmlinux1 so it has all symbols and sections,
241         #     but __kallsyms is empty.
242         #     Running kallsyms on that gives us .tmp_kallsyms1.o with
243         #     the right size
244         # 2)  Link .tmp_vmlinux2 so it now has a __kallsyms section of
245         #     the right size, but due to the added section, some
246         #     addresses have shifted.
247         #     From here, we generate a correct .tmp_kallsyms2.o
248         # 3)  That link may have expanded the kernel image enough that
249         #     more linker branch stubs / trampolines had to be added, which
250         #     introduces new names, which further expands kallsyms. Do another
251         #     pass if that is the case. In theory it's possible this results
252         #     in even more stubs, but unlikely.
253         #     KALLSYMS_EXTRA_PASS=1 may also used to debug or work around
254         #     other bugs.
255         # 4)  The correct ${kallsymso} is linked into the final vmlinux.
256         #
257         # a)  Verify that the System.map from vmlinux matches the map from
258         #     ${kallsymso}.
259
260         kallsymso=.tmp_kallsyms2.o
261         kallsyms_vmlinux=.tmp_vmlinux2
262
263         # step 1
264         vmlinux_link "" .tmp_vmlinux1
265         kallsyms .tmp_vmlinux1 .tmp_kallsyms1.o
266
267         # step 2
268         vmlinux_link .tmp_kallsyms1.o .tmp_vmlinux2
269         kallsyms .tmp_vmlinux2 .tmp_kallsyms2.o
270
271         # step 3
272         size1=$(stat -c "%s" .tmp_kallsyms1.o)
273         size2=$(stat -c "%s" .tmp_kallsyms2.o)
274
275         if [ $size1 -ne $size2 ] || [ -n "${KALLSYMS_EXTRA_PASS}" ]; then
276                 kallsymso=.tmp_kallsyms3.o
277                 kallsyms_vmlinux=.tmp_vmlinux3
278
279                 vmlinux_link .tmp_kallsyms2.o .tmp_vmlinux3
280
281                 kallsyms .tmp_vmlinux3 .tmp_kallsyms3.o
282         fi
283 fi
284
285 info LD vmlinux
286 vmlinux_link "${kallsymso}" vmlinux
287
288 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
289         info SORTEX vmlinux
290         sortextable vmlinux
291 fi
292
293 info SYSMAP System.map
294 mksysmap vmlinux System.map
295
296 # step a (see comment above)
297 if [ -n "${CONFIG_KALLSYMS}" ]; then
298         mksysmap ${kallsyms_vmlinux} .tmp_System.map
299
300         if ! cmp -s System.map .tmp_System.map; then
301                 echo >&2 Inconsistent kallsyms data
302                 echo >&2 Try "make KALLSYMS_EXTRA_PASS=1" as a workaround
303                 exit 1
304         fi
305 fi