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