qemu for arm
build uboot busybox kernel for vexpress-a9 board
use:
# build uboot
./build_arm.sh -u init -u build
# build kernel
./build_arm.sh -k init -k build -k dtbs -k modules -k uimage
# build busybox
./build_arm.sh -b init -b build -b install -b rootfs
# boot qemu
./build_arm.sh -s zimage
# 2. 宿主机创建tap0网卡
$ ifconfig
$ ip tuntap add dev tap0 mode tap
$ ip link set dev tap0 up
$ ip address add dev tap0 192.168.2.128/24
# 3. 虚拟机启动需要添加参数
# -net nic -net tap,ifname=tap0,script=no,downscript=no
$ qemu-system-arm -M vexpress-a9 \
-nographic \
-m 512M \
-kernel $UBOOT_SOURCE_ROOT/u-boot \
-net nic -net tap,ifname=tap0,script=no,downscript=no \
-append "root=/dev/mmcblk0 rw console=ttyAMA0" \
-sd $BUILD_ROOT/rootfs.ext3
#4. Uboot环境设置网络
=> setenv ipaddr 192.168.2.12 # 设置u-boot这边的地址(和br0同一网段即可)
=> setenv serverip 192.168.2.128 # 设置服务器地址(br0网桥的地址)
=> tftp 0x60003000 uImage # 从tftp下载uImage
=> tftp 0x60500000 vexpress-v2p-ca9.dtb # 从tftp下载设备树
=> setenv bootargs "root=/dev/mmcblk0 rw console=ttyAMA0" # 设置根文件系统挂载位置、权限、控制台设备
=> bootm 0x60003000 - 0x60500000 # 设置启动地址
SD卡分为4个分区，依次分别是boot/dtbs/kernel/rootfs四个分区。
# 制作SD卡镜像
$ dd if=/dev/zero of=fs_vexpress_1G.img bs=1M count=1024
# 查找第一个未使用的设备
$ losetup -f
# 挂载SD卡为loop设备， ~~目的是为了SD卡可以像物理磁盘一样被分区~~
$ sudo losetup /dev/loop0 fs_vexpress_1G.img
# 对SD卡进行分区
$ sudo fdisk /dev/loop15
# g 新建一份 GPT 分区表
# n 添加新分区
# x 高级设置
# n 更改分区名
# 最后分区信息如下
Disk /dev/loop15：1 GiB，1073741824 字节，2097152 个扇区
单元：扇区 / 1 * 512 = 512 字节
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：gpt
磁盘标识符: 750D52BA-A15A-5A4D-BE07-C20AE7A229CF
第一个 LBA: 2048
最后一个 LBA: 2097118
替代 LBA: 2097151
分区记录项 LBA: 2
已分配的分区项: 128
设备 起点 末尾 扇区 类型-UUID UUID 名称 属性
/dev/loop15p1 2048 104447 102400 0FC63DAF-8483-4772-8E79-3D69D8477DE4 95B76D16-31CE-5244-A0B1-D3DA82E01B7A uboot
/dev/loop15p2 104448 206847 102400 0FC63DAF-8483-4772-8E79-3D69D8477DE4 194BDCE1-26C7-CD47-AA26-94B26C5A3D82 dtbs
/dev/loop15p3 206848 411647 204800 0FC63DAF-8483-4772-8E79-3D69D8477DE4 0B49B892-4164-2F46-BFA7-AE27F43BAED0 kernel
/dev/loop15p4 411648 2097118 1685471 0FC63DAF-8483-4772-8E79-3D69D8477DE4 BA325D4F-BC9D-C74A-832E-B0E54086045E rootfs
# 需要执行partprobe命令才能发现新分区
$ sudo partprobe /dev/loop15
$ ls /dev/loop15p*
/dev/loop15 /dev/loop15p1 /dev/loop15p2 /dev/loop15p3 /dev/loop15p4
# 把文件系统rootfs写入p4分区
$ sudo dd if=rootfs.ext3 of=/dev/loop15p4 bs=1M count=64
# 对sd卡其它分区进行格式化
$ sudo mkfs.ext3 /dev/loop15p1
$ sudo mkfs.ext3 /dev/loop15p2
$ sudo mkfs.ext3 /dev/loop15p3
# 挂载分区
$ cd /mnt && sudo mkdir uboot dtbs rootfs kernel
$ sudo mount /dev/loop15p2 /mnt/uboot
$ sudo mount /dev/loop15p3 /mnt/dtbs
$ sudo mount /dev/loop15p4 /mnt/kernel
$ sudo mount /dev/loop15p4 /mnt/rootfs
# 拷贝镜像到分区
$ sudo cp u-boot /mnt/uboot
$ sudo cp vexpress-v2p-ca9.dtb /mnt/dtbs
$ sudo cp uImage /mnt/kernel
# 卸载分区
$ sudo umount /mnt/uboot
$ sudo umount /mnt/dtbs
$ sudo umount /mnt/rootfs
$ sudo umount /mnt/kernel
$ cd /mnt && sudo rm -rf uboot dtbs rootfs kernel
# 断开loop设备挂载
$ sudo losetup -d /dev/loop15
# qemu 启动
$ cd $UBOOT_SOURCE_ROOT
$ qemu-system-arm -M vexpress-a9 \
-kernel u-boot \
-nographic \
-m 512M \
-net nic -net tap,ifname=tap0,script=no,downscript=no \
-sd $BUILD_ROOT/fs_vexpress_1G.img
# 进入uboot命令行
# SD卡启动
=> load mmc 0:3 0x60003000 uImage
5065696 bytes read in 1463 ms (3.3 MiB/s)
=> load mmc 0:2 0x60500000 vexpress-v2p-ca9.dtb
14081 bytes read in 13 ms (1 MiB/s)
=> setenv bootargs "root=/dev/mmcblk0p4 rw console=ttyAMA0"
=> bootm 0x60003000 - 0x60500000
uboot 指令
=> help
? - alias for 'help'
base - print or set address offset
bdinfo - print Board Info structure
blkcache - block cache diagnostics and control
bootefi - Boots an EFI payload from memory
bootelf - Boot from an ELF image in memory
bootflow - Boot flows
bootm - boot application image from memory
bootp - boot image via network using BOOTP/TFTP protocol
bootvx - Boot vxWorks from an ELF image
bootz - boot Linux zImage image from memory
cmp - memory compare
cp - memory copy
crc32 - checksum calculation
dhcp - boot image via network using DHCP/TFTP protocol
echo - echo args to console
env - environment handling commands
erase - erase FLASH memory
exit - exit script
ext2load - load binary file from a Ext2 filesystem
ext2ls - list files in a directory (default /)
ext4load - load binary file from a Ext4 filesystem
ext4ls - list files in a directory (default /)
ext4size - determine a file's size
false - do nothing, unsuccessfully
fatinfo - print information about filesystem
fatload - load binary file from a dos filesystem
fatls - list files in a directory (default /)
fatmkdir - create a directory
fatrm - delete a file
fatsize - determine a file's size
fatwrite - write file into a dos filesystem
fdt - flattened device tree utility commands
flinfo - print FLASH memory information
fstype - Look up a filesystem type
fstypes - List supported filesystem types
go - start application at address 'addr'
help - print command description/usage
iminfo - print header information for application image
ln - Create a symbolic link
load - load binary file from a filesystem
loop - infinite loop on address range
ls - list files in a directory (default /)
md - memory display
mii - MII utility commands
mm - memory modify (auto-incrementing address)
mmc - MMC sub system
mmcinfo - display MMC info
mw - memory write (fill)
net - NET sub-system
nm - memory modify (constant address)
panic - Panic with optional message
part - disk partition related commands
ping - send ICMP ECHO_REQUEST to network host
printenv - print environment variables
protect - enable or disable FLASH write protection
pxe - commands to get and boot from pxe files
random - fill memory with random pattern
reset - Perform RESET of the CPU
run - run commands in an environment variable
save - save file to a filesystem
saveenv - save environment variables to persistent storage
setenv - set environment variables
showvar - print local hushshell variables
size - determine a file's size
source - run script from memory
sysboot - command to get and boot from syslinux files
test - minimal test like /bin/sh
tftpboot - boot image via network using TFTP protocol
true - do nothing, successfully
ubi - ubi commands
ubifsload - load file from an UBIFS filesystem
ubifsls - list files in a directory
ubifsmount- mount UBIFS volume
ubifsumount- unmount UBIFS volume
version - print monitor, compiler and linker version