Re: [Qemu-discuss] Coldfire 5282 Support

[William Mahoney]

Hi Thomas;

I was telling this to Peter as well offline. The initial problem just FYI was 
that the routing on the m68k side was nonexistent, so it wasn’t even sending 
anything to the net drivers at all. I turned on the debugging in the net driver 
and there was no traffic. It looks like there is a gateway set up in the 
uClinux but it’s lying.  

Now the hang-up in on my Unbuntu host side. When I do this: 

    ./bin/qemu-system-m68k \
        -cpu m5208 \
        -M mcf5208evb \
        -kernel ./coldfire-test-0.1/vmlinux-2.6.21-uc0 \
        -nographic \
        -net nic -net user,id=net0 \
        -object filter-dump,id=f1,netdev=net0,file=temp_net.pcap

The pcap shows what’s going on. QEMU does an ARP to the host and my host is … 
very very quiet. As they say in war movies, "it’s almost TOO quiet!" So I need 
to track down why here’s no resolving, then I think I’ll be good.

Bill



> On Oct 3, 2017, at 4:28 AM, Thomas Huth <address@hidden> wrote:
> 
> On 26.09.2017 23:12, William Mahoney wrote:
>> Thanks Peter!
>> 
>> Couple of new things now that I had an afternoon to look again. I have 
>> discovered that the eval board I can get my hands on is a 5272 and not a 
>> 5282, and although the eval board for a 5208 comes with a kernel the 5282 
>> does not. It only has the ROM debugger. Which makes me want to jump directly 
>> to what I really want to do anyway, which is to run the FLASH out of an 
>> Allen Bradley PLC that has a 5282 in it. Ultimately I want to monitor what 
>> the code in the PLC does when you hit it with (for example) HTTP requests. 
>> So...
>> 
>> 1) First, on the ColdFire 5208 with time uClinux kernel I can’t seem to get 
>> the networking to go. I figured I should make sure that works on the 5208 
>> before I try to get it to work on the PLC code. I’m trying to use “user” 
>> networking but no combination of -net user,id= … seems to work at all even 
>> with restrict=off. Can someone aim me at a known-to-work process for this? I 
>> sure can’t get any netcat between the guest and a netcat running on Linux. I 
>> don’t need traffic to leave the VM at all, just be able to let me get to 
>> ports in the guest from an additional xterm or local browser.
> 
> If you use the "user" networking, you've got to use "hostfwd" to forward
> ports from the host to the guest, e.g.:
> 
> qemu-system-m68k -nographic -kernel vmlinux-2.6.21-uc0 -net nic \
>                 -net user,hostfwd=tcp::8080-:8080
> 
> Then at the m68k shell, you should be able to do:
> 
> nc -l -p 8080
> 
> And in the host:
> 
> nc localhost 8080
> 
> If you now type something in the terminal, you should be able to see it
> at the other side, too.
> 
> Thomas