本文记录对ELF文件的分析，借此直观了解ELF文件。
源码
➜ elf-demo cat elf-demo.c
#include<stdio.h>
int
main(void){
printf("elf-demo\n");
}
得到ELF文件
- 得到linux ELF文件
➜ elf-demo gcc -o elf-demo elf-demo.c
➜ elf-demo file elf-demo
elf-demo: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=c74c2483765a3ff0eb84e01af94b66d644a4c224, not stripped
➜ elf-demo ./elf-demo
elf-demo
- 得到arm ELF文件
➜ elf-demo cat Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := elf-arm
LOCAL_SRC_FILES := elf-demo.c
include $(BUILD_EXECUTABLE)
➜ elf-demo ~/android-tool/android-ndk-r10e/ndk-build NDK_PROJECT_PATH=. APP_BUILD_SCRIPT=./Android.mk
[armeabi] Compile thumb : elf-arm <= elf-demo.c
[armeabi] Executable : elf-arm
[armeabi] Install : elf-arm => libs/armeabi/elf-arm
➜ elf-demo ls
Android.mk elf-demo elf-demo.c libs obj
➜ elf-demo file obj/local/armeabi/elf-arm
obj/local/armeabi/elf-arm: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked (uses shared libs), not stripped
ELF文件布局
An ELF file has two views: the program header shows the segments used at run-time, whereas the section header lists the set of sections of the binary.
各个布局详细定义见EFL wiki
参考学习方法
- 详细阅读《北京大学实验室出的标准版-ELF文件格式》
- 认真分析非虫对AndroidELF给出的概况图
- 尝试分析自己编译的ELF文件
- 明白Android .oat文件格式与加载原理