我安装并运行petalinux在 zynq 板上。它运行良好，启动时间约为 3 秒。为了如此快速地启动，我必须在编译源代码之前进行一些配置。
我现在面临的问题是，系统（热）重启后，我无法保存任何文件或文件夹。我在 /etc 中创建了一个目录，然后创建一个文件并写入一些数据，然后保存。我仔细检查了文件和文件夹确实在那里。然后我重新启动了系统（没有断开电源热启动），但现在我在那里看不到我的文件和文件夹。
另外，我以 root 身份执行所有操作，以下是部分日志消息：
U-BOOT for Xilinx-ZC702-14.7
SF: Detected N25Q128A with page size 64 KiB, total 16 MiB
SF: 3571500 bytes @ 0x520000 Read: OK
## Loading kernel from FIT Image at 01000000 ...
Using 'conf@1' configuration
Trying 'kernel@1' kernel subimage
Description: PetaLinux Kernel
Type: Kernel Image
Compression: gzip compressed
Data Start: 0x010000f0
Data Size: 3554646 Bytes = 3.4 MiB
Architecture: ARM
OS: Linux
Load Address: 0x00008000
Entry Point: 0x00008000
Verifying Hash Integrity ... OK
## Loading fdt from FIT Image at 01000000 ...
Using 'conf@1' configuration
Trying 'fdt@1' fdt subimage
Description: Flattened Device Tree blob
Type: Flat Device Tree
Compression: uncompressed
Data Start: 0x01363ef8
Data Size: 11203 Bytes = 10.9 KiB
Architecture: ARM
Hash algo: crc32
Hash value: 3ade61c7
Hash algo: sha1
Hash value: bcf959c1b25beb6f43f0d91c1ca67d9041d859ae
Verifying Hash Integrity ... crc32+ sha1+ OK
Booting using the fdt blob at 0x1363ef8
Uncompressing Kernel Image ... OK
Loading Device Tree to 07ffa000, end 07fffbc2 ... OK
Starting kernel ...
INIT: version 2.88 booting
Starting Bootlog daemon: bootlogd.
Creating /dev/flash/* device nodes
Configuring network interfaces... ifconfig: socket: Address family not supported by protocol
ifconfig: socket: Address family not supported by protocol
INIT: Entering runlevel: 5
Stopping Bootlog daemon: bootlogd.
_____ _ _ _
| ___ \ | | | | (_)
| |_/ / ___ | |_ __ _ | | _ _ __ _ _ __ __
| __/ / _ \| __| / _` || | | || '_ \ | | | |\ \/ /
| | | __/| |_ | (_| || |____| || | | || |_| | > <
\_| \___| \__| \__,_|\_____/|_||_| |_| \__,_|/_/\_\
PetaLinux v2013.10 (Yocto 1.4) Xilinx-ZC702-14_7 ttyPS0
Xilinx-ZC702-14_7 login: root
Password:
login[731]: root login on `ttyPS0'
root@Xilinx-ZC702-14_7:~# ls
root@Xilinx-ZC702-14_7:~#
是否存在许可/所有权问题？
root@Xilinx-ZC702-14_7:/# ls -ld *
drwxr-xr-x 2 root root 0 Mar 12 2014 bin
drwxr-xr-x 2 root root 0 Mar 12 2014 boot
drwxr-xr-x 5 root root 0 Jan 1 00:00 dev
drwxr-xr-x 15 root root 0 Jan 1 00:00 etc
drwxr-xr-x 3 root root 0 Mar 12 2014 home
lrwxrwxrwx 1 root root 9 Mar 12 2014 init -> sbin/init
drwxr-xr-x 3 root root 0 Mar 12 2014 lib
drwxr-xr-x 10 root root 0 Mar 12 2014 media
drwxr-xr-x 2 root root 0 Mar 12 2014 mnt
dr-xr-xr-x 40 root root 0 Jan 1 00:00 proc
drwxr-xr-x 2 root root 0 Mar 12 2014 sbin
dr-xr-xr-x 11 root root 0 Jan 1 00:00 sys
lrwxrwxrwx 1 root root 8 Mar 12 2014 tmp -> /var/tmp
drwxr-xr-x 9 root root 0 Mar 12 2014 usr
drwxr-xr-x 7 root root 0 Mar 12 2014 var
root@Xilinx-ZC702-14_7:/#
mount 的输出如下：
root@Xilinx-ZC702-14_7:/# mount
rootfs on / type rootfs (rw,relatime)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
tmpfs on /dev type tmpfs (rw,relatime,size=64k,mode=0755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
tmpfs on /var/volatile type tmpfs (rw,relatime)
tmpfs on /media/ram type tmpfs (rw,relatime)
我没有发现任何异常。我以 root 身份登录，应该有权创建文件和文件夹。
请注意，我是从闪存启动的。操作系统实际上是在 ARM Cortex A9 上运行的。
知道发生什么事了吗？
答案1
rootfs on / type rootfs (rw,relatime)
realtime节省磁盘保存次数，实际上应该只在 SSD（类似）驱动器上使用。看看这是否有帮助：
# sync
# reboot