用的busybox1.13的，2.6.13的内核，gcc是3.4.1的，通过nfs方式挂载最小文件系统，我的inittab的内容：
# /etc/inittab
::sysinit:/etc/init.d/rcS
ttySAC0::askfirst:-/bin/sh
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
rcS的内容：
# !/bin/sh
ifconfig eth0 192.168.1.17
mount -a
fstab的内容：
# device mount-point type options dump fsck order
proc /proc proc defaults 0 0
tmpfs /tmp tmpfs defaults 0 0
#sysfs /sys sysfs defaults 0 0
#tmpfs /dev tmpfs defaults 0 0
同时修改了rcS的权限，同时也把lib的内容复制了一下，同时也搞了两个节点console和null,另外busybox中也选择了mdev,mount,devfs,静态库支持等命令,命令行参数是param set linux_cmd_line "console=ttySAC0 root=/dev/nfs nfsroot=192.168.1.111:/opt/FriendlyARM/QQ2440/root_nfs ip=192.168.1.230:192.168.1.111:192.168.1.111:255.255.255.0:QQ2440V3.arm9.net:eth0:off"
结果启动部分信息如下：
S3C2440 UDA1341 audio driver initialized
NET: Registered protocol family 2
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 4096 (order: 3, 32768 bytes)
TCP bind hash table entries: 4096 (order: 2, 16384 bytes)
TCP: Hash tables configured (established 4096 bind 4096)
TCP reno registered
TCP bic registered
NET: Registered protocol family 1
NET: Registered protocol family 17
IP-Config: Complete:
device=eth0, addr=192.168.1.230, mask=255.255.255.0, gw=192.168.1.111,
host=QQ2440V3, domain=, nis-do
bootserver=192.168.1.111, rootserver=192.168.1.111, rootpath=
Looking up port of RPC 100003/2 on 192.168.1.111
Looking up port of RPC 100005/1 on 192.168.1.111
VFS: Mounted root (nfs filesystem).
Mounted devfs on /dev
Freeing init memory: 144K
/etc/init.d/rcS: line 3: mount: Permission denied
can't open /dev/ttySAC0: No such file or directory
can't open /dev/ttySAC0: No such file or directory
can't open /dev/ttySAC0: No such file or directory
我已经在这里搞了好几天了，很多都是按照书上的来的，请问我到底哪个地方不对，很纠结，请大家多多指教
