qemu以64位和32位的方式跑busybox

两种方式x86_64 和32位的i386方式

-----------x86_64-----------------------------------------

参考http://mgalgs.github.io/2015/05/16/how-to-build-a-custom-linux-kernel-for-qemu-2015-edition.html

下载busybox和linux内核

TOP=/var/www/mytest

wget http://distro.ibiblio.org/tinycorelinux/6.x/armv6/release/src/busybox/busybox-1.23.2.tar.bz2

wget https://www.kernel.org/pub/linux/kernel/v4.x/linux-4.0.3.tar.xz

cd $TOP/busybox-1.23.2

#这步骤很重要，busybox不生成动态库

mkdir -pv ../obj/busybox-x86

make O=../obj/busybox-x86 defconfig

make O=../obj/busybox-x86 menuconfig

-> Busybox Settings

-> Build Options

[ ] Build BusyBox as a static binary (no shared libs)

Go to that location, select it, save, and exit.

$ cd ../obj/busybox-x86

$ make -j2

$ make install

把busybox编译好的文件生成 initramfs

$

mkdir -p $TOP/initramfs/x86-busybox

$ cd $TOP/initramfs/x86-busybox

$ mkdir -pv {bin,sbin,etc,proc,sys,usr/{bin,sbin}}

$ cp -av $TOP/obj/busybox-x86/_install/* .

需要一个启动文件

vim init

-------------

#!/bin/sh

mount -t proc none /proc

mount -t sysfs none /sys

echo -e "\nBoot took $(cut -d' ' -f1 /proc/uptime) seconds\n"

exec /bin/sh

--------------------

chmod +x init

find . -print0  | cpio --null -ov --format=newc  | gzip -9 > $TOP/obj/initramfs-busybox-x86.cpio.gz

★★★★编译内核★★★★★★★★

linux Kernel

$

cd $TOP/linux-4.0.3

$ make O=../obj/linux-x86-basic x86_64_defconfig

make O=../obj/linux-x86-basic kvmconfig

#支持kvm

make O=../obj/linux-x86-basic -j2

$ cd $TOP

运行

qemu-system-x86_64 -kernel obj/linux-x86-basic/arch/x86_64/boot/bzImage -initrd obj/initramfs-busybox-x86.cpio.gz -nographic -append "console=ttyS0" -enable-kvm

------------------------------------------------------------

i386★★★★★★★★★★如果是在64为系统上编译32位，有点特殊

------------------------------------------------------------

这步骤很重要，busybox不生成动态库

cd $TOP/busybox-1.23.2

mkdir -pv ../obj/busybox-i386

make O=../obj/busybox-i386 defconfig

make O=../obj/busybox-i386 menuconfig

-> Busybox Settings

-> Build Options

[ ] Build BusyBox as a static binary (no shared libs)

Go to that location, select it, save, and exit.

$ cd ../obj/busybox-i386

参考

http://blog.csdn.net/xsckernel/article/details/38045783

想编译32为的环境

将/usr/bin/gcc和/usr/bin/ld都改名为*.bin，就是改为： /usr/bin/gcc.bin和/usr/bin/ld.bin

然后写两个脚本：

/usr/bin/gcc:

---------------------

#!/bin/sh

gcc.bin -m32 $@

------------------------

/usr/bin/ld:

------------------

#!/bin/sh

ld.bin -m elf_i386 $@

---------------------

还需要

yum install glibc.i686 glibc-devel.i686 glibc-static.i686 glibc-utils.x86_64 -y

yum install libgcc.i686 -y

测试是否切换到i386

--------test.c--------

#include

#include

int main()

{

printf("sizeof long is %d\n", sizeof(long));

return 0;

}

-----------------

gcc test.c

file a.out

a.out: ELF 32-bit LSB executable,

继续以32位的方式编译busybox

$ make  -j2

$ make install

生成initramfs：

$ mkdir -p $TOP/initramfs/i386-busybox

$ cd $TOP/initramfs/i386-busybox

$ mkdir -pv {bin,sbin,etc,proc,sys,usr/{bin,sbin}}

$ cp -av $TOP/obj/busybox-i386/_install/* .

vim init

-------------

#!/bin/sh

mount -t proc none /proc

mount -t sysfs none /sys

echo -e "\nBoot took $(cut -d' ' -f1 /proc/uptime) seconds\n"

exec /bin/sh

--------------------

chmod +x init

find . -print0 | cpio --null -ov --format=newc | gzip -9 > $TOP/obj/initramfs-busybox-i386.cpio.gz

--------------------------

★★★★★★编译32位的内核比较简单，只需要加ARCH=i386

--------------------------

make O=../obj/linux-i386-basic i386_defconfig

make O=../obj/linux-i386-basic kvmconfig

make O=../obj/linux-i386-basic ARCH=i386 -j16

qemu-system-i386 -kernel obj/linux-i386-basic/arch/x86/boot/bzImage -initrd obj/initramfs-busybox-i386.cpio.gz -nographic -append "console=ttyS0" -enable-kvm

-----------------------------------------------------------------------------

系统切换回64位环境

[root@jslinux mytest]# cat gcc64.sh

#!/bin/sh

mv -i /usr/bin/gcc /usr/bin/gcc.sh

mv -i /usr/bin/ld  /usr/bin/ld.sh

mv -i /usr/bin/gcc.bin /usr/bin/gcc

mv -i /usr/bin/ld.bin  /usr/bin/ld

系统切换回32位环境

[root@jslinux mytest]# cat gcc32.sh

#!/bin/sh

mv -i /usr/bin/gcc /usr/bin/gcc.bin

mv -i /usr/bin/ld  /usr/bin/ld.bin

mv -i /usr/bin/gcc.sh /usr/bin/gcc

mv -i /usr/bin/ld.sh  /usr/bin/ld

------------------------------------------------------------------------