objdump -t xxx.o
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ objdump -t main.o
main.o: file format elf32-little
SYMBOL TABLE:
00000000 l df *ABS* 00000000 main.c
00000000 l d .text 00000000 .text
00000000 l d .data 00000000 .data
00000000 l d .bss 00000000 .bss
00000000 l d .mdebug.abi32 00000000 .mdebug.abi32
00000000 l d .rodata 00000000 .rodata
00000000 l d .reginfo 00000000 .reginfo
00000000 l d .pdr 00000000 .pdr
00000000 l d .comment 00000000 .comment
00000000 l d .gnu.attributes 00000000 .gnu.attributes
00000000 g F .text 000000dc demo1
00000000 *UND* 00000000 GetIdChipSerialNo
00000000 *UND* 00000000 printf
00000000 *UND* 00000000 putchar
000000dc g F .text 0000027c demo2
00000000 *UND* 00000000 _alpu_rand
00000000 *UND* 00000000 gettimeofday
00000000 *UND* 00000000 alpuc_process
00000000 *UND* 00000000 puts
00000358 g F .text 0000003c main
readelf -h xxx.o
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ readelf -h main.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: MIPS R3000
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 1624 (bytes into file)
Flags: 0x1005, noreorder, cpic, o32, mips1
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 15
Section header string table index: 12
readelf -s main.o
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ readelf -s main.o
Symbol table '.symtab' contains 21 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 FILE LOCAL DEFAULT ABS main.c
2: 00000000 0 SECTION LOCAL DEFAULT 1
3: 00000000 0 SECTION LOCAL DEFAULT 3
4: 00000000 0 SECTION LOCAL DEFAULT 4
5: 00000000 0 SECTION LOCAL DEFAULT 8
6: 00000000 0 SECTION LOCAL DEFAULT 9
7: 00000000 0 SECTION LOCAL DEFAULT 5
8: 00000000 0 SECTION LOCAL DEFAULT 6
9: 00000000 0 SECTION LOCAL DEFAULT 10
10: 00000000 0 SECTION LOCAL DEFAULT 11
11: 00000000 220 FUNC GLOBAL DEFAULT 1 demo1
12: 00000000 0 NOTYPE GLOBAL DEFAULT UND GetIdChipSerialNo
13: 00000000 0 NOTYPE GLOBAL DEFAULT UND printf
14: 00000000 0 NOTYPE GLOBAL DEFAULT UND putchar
15: 000000dc 636 FUNC GLOBAL DEFAULT 1 demo2
16: 00000000 0 NOTYPE GLOBAL DEFAULT UND _alpu_rand
17: 00000000 0 NOTYPE GLOBAL DEFAULT UND gettimeofday
18: 00000000 0 NOTYPE GLOBAL DEFAULT UND alpuc_process
19: 00000000 0 NOTYPE GLOBAL DEFAULT UND puts
20: 00000358 60 FUNC GLOBAL DEFAULT 1 main
nm xxx.o 对比g++编译程序生成的符号表与gcc生成的不同点。
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ nm main.o #g++ compile
U _Z10_alpu_randv
U _Z13alpuc_processPhS_
U _Z17GetIdChipSerialNoPh
00000000 T _Z5demo1v
000000dc T _Z5demo2v
U gettimeofday
00000358 T main
U printf
U putchar
U puts
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ mipsel-openwrt-linux-gcc -c main.c
mipsel-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
weeds@weeds-ThinkPad-T440p:~/Documents/encrypchip$ nm main.o #gcc compile
U GetIdChipSerialNo
U _alpu_rand
U alpuc_process
00000000 T demo1
000000dc T demo2
U gettimeofday
00000358 T main
U printf
U putchar
U puts