配置交叉编译工具链
先安装一些必要的软件
sudo apt install build-essential open-vm-tools open-vm-tools-desktop
然后安装交叉编译工具链
sudo apt install gcc-arm-linux-gnueabi
sudo apt install g++-arm-linux-gnueabi
安装QEMU
下载
下载9.2.4版本
wget https://download.qemu.org/qemu-9.2.4.tar.xz
tar -xf qemu-9.2.4.tar.xz
安装依赖
必要依赖：
sudo apt-get install git libglib2.0-dev libfdt-dev libpixman-1-dev zlib1g-dev ninja-build
推荐依赖：
sudo apt-get install git-email
sudo apt-get install libaio-dev libbluetooth-dev libcapstone-dev libbrlapi-dev libbz2-dev
sudo apt-get install libcap-ng-dev libcurl4-gnutls-dev libgtk-3-dev
sudo apt-get install libibverbs-dev libjpeg8-dev libncurses5-dev libnuma-dev
sudo apt-get install librbd-dev librdmacm-dev
sudo apt-get install libsasl2-dev libsdl2-dev libseccomp-dev libsnappy-dev libssh-dev
sudo apt-get install libvde-dev libvdeplug-dev libvte-2.91-dev libxen-dev liblzo2-dev
sudo apt-get install valgrind xfslibs-dev
sudo apt-get install libnfs-dev libiscsi-dev
编译安装
首先配置目标为ARM架构
./configure --target-list=arm-softmmu
然后编译并安装
make -j$(nproc); sudo make install
编译Linux内核
下载
wget https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.35.tar.xz
tar -xf linux-6.12.35.tar.xz
编译
首先设置ARCH和CROSS_COMPILE，修改Makefile中对应字段为：
ARCH ?= arm
CROSS_COMPILE ?= arm-linux-gnueabi-
安装依赖之前，先配置一下软件源，之前忘改了，修改/etc/apt/sources.list.d/ubuntu.sources
Types: deb
URIs: https://mirrors.tuna.tsinghua.edu.cn/ubuntu
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Types: deb-src
URIs: https://mirrors.tuna.tsinghua.edu.cn/ubuntu
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Types: deb
URIs: http://security.ubuntu.com/ubuntu/
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Types: deb-src
URIs: http://security.ubuntu.com/ubuntu/
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
然后安装依赖
sudo apt update
sudo apt build-dep linux
在menuconfig中，勾选Device Drivers —>Network device support —> Universal TUN/TAP device driver support
make vexpress_defconfig;make menuconfig
之后开始编译
make zImage
make modules; make dtbs
现在可以通过下面的指令，直接启动内核
qemu-system-arm \
-M vexpress-a9 \
-m 512M \
-kernel arch/arm/boot/zImage \
-dtb arch/arm/boot/dts/arm/vexpress-v2p-ca9.dtb \
-nographic \
-append "console=ttyAMA0"
最终输出
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.35 #1
Hardware name: ARM-Versatile Express
Call trace:
unwind_backtrace from show_stack+0x10/0x14
show_stack from dump_stack_lvl+0x54/0x68
dump_stack_lvl from panic+0x10c/0x350
panic from mount_root_generic+0x238/0x2e8
mount_root_generic from prepare_namespace+0x1fc/0x254
prepare_namespace from kernel_init+0x1c/0x12c
kernel_init from ret_from_fork+0x14/0x28
Exception stack(0xa0825fb0 to 0xa0825ff8)
5fa0: 00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---
PS: QEMU可以按Ctrl+a，再按c调出monitor，然后输入q既可退出QEMU
制作根文件系统
下载
wget https://busybox.net/downloads/busybox-1.37.0.tar.bz2
tar -xf busybox-1.37.0.tar.bz2
编译
首先还是设置CROSS_COMPILE和ARCH，然后开始配置
make defconfig; make menuconfig
勾选 Settings -> Build static binary (no shared libs)选项
然后执行编译和安装
make; make install
出现了一个错误
libbb/hash_md5_sha.c: In function ‘sha1_end’:
libbb/hash_md5_sha.c:1316:35: error: ‘sha1_process_block64_shaNI’ undeclared (first use in this function); did you mean ‘sha1_process_block64’?
1316 | || ctx->process_block == sha1_process_block64_shaNI
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
| sha1_process_block64
libbb/hash_md5_sha.c:1316:35: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [scripts/Makefile.build:198: libbb/hash_md5_sha.o] Error 1
make: *** [Makefile:744: libbb] Error 2
CC libbb/hash_md5_sha.o
libbb/hash_md5_sha.c: In function ‘sha1_end’:
libbb/hash_md5_sha.c:1316:35: error: ‘sha1_process_block64_shaNI’ undeclared (first use in this function); did you mean ‘sha1_process_block64’?
1316 | || ctx->process_block == sha1_process_block64_shaNI
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
| sha1_process_block64
libbb/hash_md5_sha.c:1316:35: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [scripts/Makefile.build:198: libbb/hash_md5_sha.o] Error 1
make: *** [Makefile:744: libbb] Error 2
一个解决方法是修改配置，禁用对SHA1和SHA256的硬件加速选项，取消勾选Settings-> SHA1: Use hardware accelerated instructions if possible 以及 Settings-> SHA256: Use hardware accelerated instructions if possible
然后重新编译，又遇到了新问题，报错很长，截取了前半部分，看到是在编译tc.c啥的出错了，那就再把它取消勾选，在Networking Utilities中。
networking/tc.c:236:24: warning: unused variable ‘tb’ [-Wunused-variable]
236 | struct rtattr *tb[TCA_CBQ_MAX+1];
| ^~
make[1]: *** [scripts/Makefile.build:198: networking/tc.o] Error 1
make: *** [Makefile:744: networking] Error 2
CC networking/tc.o
networking/tc.c: In function ‘cbq_print_opt’:
networking/tc.c:236:27: error: ‘TCA_CBQ_MAX’ undeclared (first use in this function); did you mean ‘TCA_CBS_MAX’?
236 | struct rtattr *tb[TCA_CBQ_MAX+1];
| ^~~~~~~~~~~
| TCA_CBS_MAX
重新编译后终于通过
制作根文件系统
在当前用户的家目录下新建一个文件夹作为虚拟机的根文件系统
mkdir ~/rootfs
cp -r _install/* ~/rootfs
然后创建一些基本的目录和设备节点
sudo mkdir -p dev etc lib proc sys tmp root
sudo mknod dev/console c 5 1
sudo mknod dev/null c 1 3
接下来，需要拷贝交叉编译工具的库文件到根文件系统
sudo cp /usr/arm-linux-gnueabi/lib/* ~/rootfs/lib/
最后编译以下文件，完善文件系统
-
/etc/fstab 该文件用于配置文件系统挂载信息
proc /proc proc defaults 0 0 tmpfs /tmp tmpfs defaults 0 0 sysfs /sys sysfs defaults 0 0 tmpfs /dev tmpfs defaults 0 0 var /dev tmpfs defaults 0 0 ramfs /dev ramfs defaults 0 0 -
/etc/inittab 该文件用于配置一些基本设置。第一行执行系统初始化脚本；第二行在控制台上启用一个交互式的shell；第三行定义当按下 Ctrl+Alt+Delete 组合键时的系统行为；第四行定义了在系统关闭过程中要执行的命令
::sysinit:/etc/init.d/rcS console::askfirst:-/bin/sh ::ctrlaltdel:/sbin/reboot ::shutdown:/bin/umount -a -r -
/etc/profile 定义了命令提示符
PS1='szy@vexpress:\w # ' export PS1 -
/etc/init.d/ 定义了一些环境变量，以及负责挂载文件系统
#!/bin/sh PATH=/sbin:/bin:/usr/sbin:/usr/bin LD_LIBRARY_PATH=/lib export PATH LD_LIBRARY_PATH mount -a mkdir -p /dev/pts mount -t devpts devpts /dev/pts mdev -s mkdir -p /var/lock echo "--------------------------------" echo " Welcome to A9 vexpress board " echo "--------------------------------"
编译U-Boot
下载
wget https://ftp.denx.de/pub/u-boot/u-boot-2025.04.tar.bz2
tar -xf u-boot-2025.04.tar.bz2
编译
分别编辑Makefile和config.mk，设置CROSS_COMPILE和ARCH字段
ARCH ?= arm # 在config.mk中
CROSS_COMPILE ?= arm-linux-gnueabi- # 在Makefile中
编译：
make vexpress_ca9x4_defconfig
make -j$(nproc)
配置NFS
这一步的目的是，让虚拟机通过NFS的方式挂载宿主机上的根文件系统，这样就可以实现在宿主机上开发，实时同步修改到虚拟机。
安装NFS
-
安装nfs服务器
sudo apt install nfs-kernel-server -
配置nfs，修改
/etc/exports，在底下加上一行/home/szy/rootfs (rw,sync,no_root_squash,no_subtree_check) -
重启nfs服务
sudo /etc/init.d/rpcbind restart sudo /etc/init.d/nfs-kernel-server restart
网络配置
这一步的目的是连接QEMU虚拟机与宿主机的网络，采用桥接方式。大致思路是在宿主机创建一个虚拟网桥br0，接入网卡eth0与TAP设备tap0，在QEMU虚拟机处连接网卡eth0与宿主机tap0，实现互通。
在/etc/netplan/目录下创建一个yaml文件，内容如下：
network:
version: 2
renderer: NetworkManager
ethernets:
ens33: # 物理网卡
dhcp4: no # 自身不获取IP
bridges:
br0: # 创建的网桥
interfaces: [ens33] # 将物理网卡桥接进来
dhcp4: yes # 让网桥自动获取IP
parameters:
stp: false
保存后输入sudo netplan apply应用更改，然后在/etc/systemd/system目录下创建一个systemd服务：
[Unit]
Description=Persistent TAP device for QEMU
Wants=network-pre.target
Before=network-pre.target
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/sbin/ip tuntap add dev tap-qemu mode tap
ExecStop=/usr/sbin/ip tuntap del dev tap-qemu mode tap
[Install]
WantedBy=multi-user.target
最后启动新服务，这样就可以在开机时自动配置TAP设备
sudo systemctl enable qemu-tap.service
sudo systemctl start qemu-tap.service
然后让我们配置一下虚拟机，创建 /etc/qemu-ifup，写入如下内容：
#! /bin/sh
# Script to bring a network (tap) device for qemu up.
# The idea is to add the tap device to the same bridge
# as we have default routing to.
# in order to be able to find brctl
PATH=$PATH:/sbin:/usr/sbin
ip=$(which ip)
if [ -n "$ip" ]; then
ip link set "$1" up
else
brctl=$(which brctl)
if [ ! "$ip" -o ! "$brctl" ]; then
echo "W: $0: not doing any bridge processing: neither ip nor brctl utility not found" >&2
exit 0
fi
ifconfig "$1" 0.0.0.0 up
fi
switch=$(ip route ls | \
awk '/^default / {
for(i=0;i<NF;i++) { if ($i == "dev") { print $(i+1); next; } }
}'
)
# only add the interface to default-route bridge if we
# have such interface (with default route) and if that
# interface is actually a bridge.
# It is possible to have several default routes too
for br in $switch; do
if [ -d /sys/class/net/$br/bridge/. ]; then
if [ -n "$ip" ]; then
ip link set "$1" master "$br"
else
brctl addif $br "$1"
fi
exit # exit with status of the previous command
fi
done
echo "W: $0: no bridge for guest interface found" >&2
重新编译U-Boot
修改U-Boot目录下 /include/configs/vexpress_common.h，添加如下内容：
#define CONFIG_BOOTCOMMAND \
"tftp 0x60003000 uImage;tftp 0x60500000 vexpress-v2p-ca9.dtb; \
setenv bootargs 'root=/dev/nfs rw \
nfsroot=192.168.110.136:/home/szy/rootfs \
ip=192.168.110.137 console=ttyAMA0';\
bootm 0x60003000 - 0x60500000; "
#define CONFIG_IPADDR 192.168.110.137
#define CONFIG_NETMASK 255.255.255.0
#define CONFIG_SERVERIP 192.168.110.136
然后修改QEMU启动脚本，启动时调用/etc/qemu-ifup脚本，这样我们的QEMU开发环境就完成了。在这里我的内核和设备树都通过tftp获取。
qemu-system-arm \
-M vexpress-a9 \
-m 512M \
-kernel /home/szy/linux/tftpboot/u-boot \
-nographic \
-nic tap,script=/etc/qemu-ifup,downscript=no \
-audiodev none,id=silent