# Firewire RAM access



## hyperwizard (Jul 27, 2010)

Hi,

I was playing around with fwcontrol and its "-m" switch. 
I connected my FreeBSD 7.2 notebook to Win7 PC Via firewire and attempted to access Win7's RAM through the /dev/fwmem interface. I failed. 


```
5 root@purevil:ttyv0 ~ 15:11:24 > fwcontrol
2 devices (info_len=2)
node           EUI64          status    hostname
   0  00-1d-72-ff-ff-c5-6b-71      0
  -1  00-1e-8c-00-01-7b-f5-38      0
```
Then I plugged in the cable:

```
fwohci0: BUS reset
fwohci0: node_id=0xc000ffc1, gen=8, CYCLEMASTER mode
firewire0: 2 nodes, maxhop <= 1, cable IRM = 1 (me)
firewire0: bus manager 1 (me)

5 root@purevil:ttyv0 ~ 15:11:46 > fwcontrol
2 devices (info_len=2)
node           EUI64          status    hostname
   1  00-1d-72-ff-ff-c5-6b-71      0
   0  00-1e-8c-00-01-7b-f5-38      1
5 root@purevil:ttyv0 ~ 15:11:49 > fwcontrol -m 00-1e-8c-00-01-7b-f5-38
0 root@purevil:ttyv0 ~ 15:12:00 > ll /dev/fwmem*
lrwxr-xr-x  1 root  wheel            8 27 Jul 14:56 /dev/fwmem0 -> fwmem0.0
crw-rw----  1 root  operator    0,  53 27 Jul 14:56 /dev/fwmem0.0
0 root@purevil:ttyv0 ~ 15:12:04 > more /dev/fwmem0
read error  (press RETURN)
```

The question is.. Should this always work? As far as I know I should be able to access other PC's RAM through the firewire connection without any support from the connected PC's OS, right?


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