Wow...happy new year, and nice to hear from you again Mulyadi!!! On Fri, Jan 2, 2009 at 8:59 PM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > On Tue, Dec 30, 2008 at 9:17 AM, pl ice <telent997@xxxxxxxxx> wrote: >> Hi buddy, >> I found kernel use Kbuild to make obj-file,and I objdumped >> these obj file and found they all had section .debug. I think they >> will make building kernel use much more time.why these >> obj file compile to debug version? > > I check that .debug sections are created whenever you use gcc to > create new object file. I guess you mistakenly assume they were the > sections used by gdb to debug the binary, not they are not. > First I used gcc on a C file, and both object and elf output does not have any debug related information after "objdump -x". Next I used "gcc -g" on the C file, and both the object and ELF output have lots of debug related information, something like the following (which is "objdump -x vmlinux"): 39 .debug_aranges 0000c7d0 00000000 00000000 004bac78 2**3 40 .debug_pubnames 0003e96f 00000000 00000000 004c7448 2**0 41 .debug_info 0308daa6 00000000 00000000 00505db7 2**0 42 .debug_abbrev 001525c5 00000000 00000000 0359385d 2**0 43 .debug_line 00295fa6 00000000 00000000 036e5e22 2**0 44 .debug_frame 0008dd30 00000000 00000000 0397bdc8 2**2 45 .debug_str 00114de3 00000000 00000000 03a09af8 2**0 46 .debug_loc 0033f6b8 00000000 00000000 03b1e8db 2**0 47 .debug_ranges 0007f728 00000000 00000000 03e5df93 2**0 00000000 l d .debug_aranges 00000000 .debug_aranges 00000000 l d .debug_pubnames 00000000 .debug_pubnames 00000000 l d .debug_info 00000000 .debug_info 00000000 l d .debug_abbrev 00000000 .debug_abbrev 00000000 l d .debug_line 00000000 .debug_line 00000000 l d .debug_frame 00000000 .debug_frame 00000000 l d .debug_str 00000000 .debug_str 00000000 l d .debug_loc 00000000 .debug_loc 00000000 l d .debug_ranges 00000000 .debug_ranges RELOCATION RECORDS FOR [.debug_aranges]: 00000006 R_386_32 .debug_info 0000045e R_386_32 .debug_info 0000047e R_386_32 .debug_info 0000049e R_386_32 .debug_info And so the key difference is "-g". Looking into Makefile in root directory of kernel source: ifdef CONFIG_DEBUG_INFO KBUILD_CFLAGS += -g KBUILD_AFLAGS += -gdwarf-2 endif So after all it should be CONFIG_DEBUG_INFO which resulted in these debug section. > If you don't need them, simply use "strip". yes, u are right, after "strip"-ping, everything is gone. > > regards, > > Mulyadi. -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
