[Qemu-devel] ssh session with qemu-arm using busybox

[Dongli Zhang]

On 3/13/19 1:08 AM, Pintu Agarwal wrote:
> On Tue, Mar 12, 2019 at 7:41 PM Suzuki K Poulose <suzuki.poulose at arm.com> wrote:
>>
>>
>>
>> On 12/03/2019 14:02, Pintu Agarwal wrote:
>>>>
>>>> -netdev user,id=unet,hostfwd=tcp::2222-:22 \
>>>> -net user \
>>>>
>>>> and you 'll get guest's port 22 to be forwarded to hosts port 2222, so
>>>> you can do
>>>>
>>>> ssh root at localhost:2222
>>>>
>>>> from the host.
>>>>
>>>
>>> I tried many different options, but unfortunately none worked for me.
>>> 1)
>>> qemu-system-arm -M vexpress-a9 -m 1024M -kernel
>>> ../KERNEL/linux/arch/arm/boot/zImage -dtb
>>> ../KERNEL/linux/arch/arm/boot/dts/vexpress-v2p-ca9.dtb -initrd
>>> rootfs.img.gz -append "console=ttyAMA0 root=/dev/ram rdinit=/sbin/init
>>> ip=dhcp" -nographic -smp 4 -netdev user,id=unet,hostfwd=tcp::2222-:22
>>> -net user
>>>
>>> With this the eth0 interface is removed, and I see this message
>>> (although login works):
>>> qemu-system-arm: warning: hub 0 with no nics
>>> qemu-system-arm: warning: netdev unet has no peer
>>> Booting Linux on physical CPU 0x0
>>> <skip>
>>> NET: Registered protocol family 17
>>> <skip>
>>> Run /sbin/init as init process
>>> ifconfig: SIOCSIFADDR: No such device
>>> route: SIOCADDRT: Network is unreachable
>>>
>>> But, ssh is still not working.
>>> ssh root at localhost:2222
>>> ssh: Could not resolve hostname localhost:2222: Name or service not known
>>
>> man ssh
>>
>> +
>>
>> Make sure you have sshd in your custom rootfs and has been stared.
>>
> 
> My busybox is a very minimal rootfs. It hardly contains any commands.
> Is there any precompiled busybox for arm (cpio image), available (with
> ssh, scp and networking in-built), which I can use directly to boot ?
> 
> what else I am missing to make ssh/scp working on qemu ?
> 

When I was working on arm binary rewriting/instrumentation in the university, I
use the image created by Linaro.

http://releases.linaro.org/

One example would be

https://www.linaro.org/blog/linaro-16-04-release-available-for-download-2/

or

https://releases.linaro.org/archive/ubuntu/images/developer-arm64/15.12/linaro-vivid-developer-20151215-114.tar.gz

The license should be good for academia. I do not know if there is any
restrictions on commercial/industry usage.

Thank for Linaro again for providing those images which helped me a lot when I
was in the university!

Dongli Zhang