Re: [Qemu-devel] Welcome to the "Qemu-devel" mailing list (Digest mode)

[郭明哲]

Dear,
    Is anyone can help me? I'm deeply in trouble. I want boot by kernel by qemu, i want boot from dhcp, but i got error,
i have no idea on this, two days... i cannot find the solution. Anyone knows why? Thanks very much.

command:
/tftpboot/i686/usbqemu# qemu-system-i386 -M pc -kernel /tftpboot/i686/usbqemu/bzImage -append "ip=on console=ttyS0" -boot nc -net nic,macaddr=52:54:00:12:34:58 -net tap -nographic

dhcp.conf:
subnet 192.168.1.0 netmask 255.255.255.0
{
    next-server 192.168.1.100;
    host qemu-i386 {
    hardware ethernet 52:54:00:12:34:58;
    fixed-address 192.168.1.200;
    option root-path "/tftpboot/i686/usbqemu";
    }
}

ifconfig:
eth1      Link encap:Ethernet  HWaddr 54:e6:fc:6a:58:46  
          inet addr:43.82.111.3  Bcast:43.82.111.255  Mask:255.255.255.0
          inet6 addr: fe80::56e6:fcff:fe6a:5846/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:61228 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6236 errors:0 dropped:0 overruns:0 carrier:0
          collisions:2253 txqueuelen:1000 
          RX bytes:11562436 (11.5 MB)  TX bytes:1123459 (1.1 MB)
          Interrupt:16 Base address:0xe800 

eth2      Link encap:Ethernet  HWaddr 6c:62:6d:6c:63:e0  
          inet addr:10.0.0.7  Bcast:10.255.255.255  Mask:255.0.0.0
          inet6 addr: fe80::6e62:6dff:fe6c:63e0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:309855 errors:0 dropped:0 overruns:0 frame:0
          TX packets:10456 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:76918528 (76.9 MB)  TX bytes:485066 (485.0 KB)
          Interrupt:41 Base address:0xe000 

nfs(exports file):
/tftpboot *(rw,sync,no_root_squash,no_subtree_check,insecure)
/tftpboot/i686/usbqemu *(rw,sync,no_root_squash,no_subtree_check,insecure)

br0-ifup( a script):
IP=192.168.1.100
BROADCAST=192.168.1.255                                                                                 
/usr/sbin/brctl addbr br0
/sbin/ifconfig br0 $IP netmask 255.255.255.0 broadcast $BROADCAST up
/usr/sbin/brctl stp br0 off
/usr/sbin/brctl setfd br0 1
/usr/sbin/brctl sethello br0 1
echo 1024 > /proc/sys/dev/hpet/max-user-freq
chmod 666 /dev/net/tun
chmod 755 /etc/qemu-ifup
echo "# Command line options here                                                       
INTERFACES=\"eth2 br0\" "> /etc/default/isc-dhcp-server
/etc/init.d/isc-dhcp-server start
    
qemu-ifup:
/sbin/ifconfig $1 0.0.0.0 promisc up
/usr/sbin/brctl addif br0 $1


bellow is kernel error message:

[   13.087298] VFS: Cannot open root device "(null)" or unknown-block(8,1)
[   13.089471] Please append a correct "root=" boot option; here are the available partitions:
[   13.092270] 0b00         1048575 sr0 driver: sr
[   13.093812] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1)
[   13.096596] Pid: 1, comm: swapper Not tainted 2.6.35.13_nl-pc+ #1
[   13.098611] Call Trace:
[   13.098958]  [<c1030bf9>] panic+0x7f/0x100
[   13.099558]  [<c1791c95>] mount_block_root+0x156/0x165
[   13.100271]  [<c1002931>] ? sysenter_past_esp+0x4e/0x57
[   13.100978]  [<c1791d0a>] mount_root+0x66/0x84
[   13.101606]  [<c1791e73>] prepare_namespace+0x14b/0x172
[   13.102363]  [<c1791630>] kernel_init+0x1ad/0x1bc
[   13.103031]  [<c1791483>] ? kernel_init+0x0/0x1bc
[   13.103674]  [<c1002eb6>] kernel_thread_helper+0x6/0x10