f197d75fca
Some macro's and defines are needed when parsing memory, and without compiling the kernel as -g3 they are not available in the debug-symbols. We use the pre-processor here to extract constants to a dedicated module for the linux debugger extensions Top level Kbuild is used to call in and generate the constants file, while maintaining dependencies on autogenerated files in include/generated Link: http://lkml.kernel.org/r/bc3df9c25f57ea72177c066a51a446fc19e2c27f.1462865983.git.jan.kiszka@siemens.com Signed-off-by: Kieran Bingham <kieran.bingham@linaro.org> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.8 KiB
Kbuild for top-level directory of the kernel
This file takes care of the following:
1) Generate bounds.h
2) Generate timeconst.h
3) Generate asm-offsets.h (may need bounds.h and timeconst.h)
4) Check for missing system calls
5) Generate constants.py (may need bounds.h)
Default sed regexp - multiline due to syntax constraints
define sed-y
"/^->/{s:->#.*:/* \1 /:;
s:^->[^ ]* [$$#][-0-9]* .*:#define \1 \2 /* \3 /:;
s:^->[^ ]* [$$#][^ ]* .*:#define \1 \2 /* \3 */:;
s:->::; p;}"
endef
Use filechk to avoid rebuilds when a header changes, but the resulting file
does not
define filechk_offsets
(set -e;
echo "#ifndef $2";
echo "#define $2";
echo "/*";
echo " * DO NOT MODIFY.";
echo " *";
echo " * This file was generated by Kbuild";
echo " */";
echo "";
sed -ne $(sed-y);
echo "";
echo "#endif" )
endef
1) Generate bounds.h
bounds-file := include/generated/bounds.h
always := $(bounds-file) targets := kernel/bounds.s
We use internal kbuild rules to avoid the "is up to date" message from make
kernel/bounds.s: kernel/bounds.c FORCE $(Q)mkdir -p $(dir $@) $(call if_changed_dep,cc_s_c)
$(obj)/$(bounds-file): kernel/bounds.s FORCE $(call filechk,offsets,LINUX_BOUNDS_H)
2) Generate timeconst.h
timeconst-file := include/generated/timeconst.h
targets += $(timeconst-file)
quiet_cmd_gentimeconst = GEN $@ define cmd_gentimeconst (echo $(CONFIG_HZ) | bc -q $< ) > $@ endef define filechk_gentimeconst (echo $(CONFIG_HZ) | bc -q $< ) endef
$(obj)/$(timeconst-file): kernel/time/timeconst.bc FORCE $(call filechk,gentimeconst)
3) Generate asm-offsets.h
offsets-file := include/generated/asm-offsets.h
always += $(offsets-file) targets += arch/$(SRCARCH)/kernel/asm-offsets.s
We use internal kbuild rules to avoid the "is up to date" message from make
arch/$(SRCARCH)/kernel/asm-offsets.s: arch/$(SRCARCH)/kernel/asm-offsets.c
$(obj)/$(timeconst-file) $(obj)/$(bounds-file) FORCE
$(Q)mkdir -p $(dir $@)
$(call if_changed_dep,cc_s_c)
$(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s FORCE $(call filechk,offsets,ASM_OFFSETS_H)
4) Check for missing system calls
always += missing-syscalls targets += missing-syscalls
quiet_cmd_syscalls = CALL $< cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags) $(missing_syscalls_flags)
missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE $(call cmd,syscalls)
5) Generate constants for Python GDB integration
extra-$(CONFIG_GDB_SCRIPTS) += build_constants_py
build_constants_py: $(obj)/$(timeconst-file) $(obj)/$(bounds-file) @$(MAKE) $(build)=scripts/gdb/linux $@
Keep these three files during make clean
no-clean-files := $(bounds-file) $(offsets-file) $(timeconst-file)