# How to force dd to operate to install netbsd ?



## honeybear (Nov 26, 2022)

Hello,

My image is here:


```
root@generic:~ # gpart show
=>      63  15523777  mmcsd0  MBR  (7.4G)
        63      2016          - free -  (1.0M)
      2079    102312       1  fat32lba  [active]  (50M)
    104391  15419449       2  freebsd  (7.4G)

=>       0  15419449  mmcsd0s2  BSD  (7.4G)
         0        57            - free -  (29K)
        57  15419392         1  freebsd-ufs  (7.4G)

=>      63  15728577  da0  MBR  (7.5G)
        63     32705       - free -  (16M)
     32768    163840    1  fat32lba  [active]  (80M)
    196608   2185728    2  !169  (1.0G)
   2382336  13346304       - free -  (6.4G)

=>      63  15728577  diskid/DISK-81BE174E  MBR  (7.5G)
        63     32705                        - free -  (16M)
     32768    163840                     1  fat32lba  [active]  (80M)
    196608   2185728                     2  !169  (1.0G)
   2382336  13346304                        - free -  (6.4G)
```


```
root@generic:~ # dd if=/dev/da0 of=/dev/mmcsd0 count=196608 ; sync ; reboot
dd: /dev/mmcsd0: Operation not permitted
```

but it fails

Any idea welcome to force dd to operate?


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## covacat (Nov 26, 2022)

try 

sysctl kern.geom.debugflags=16
read man 4 geom

0x10 (allow foot shooting)
             Allow writing to Rank 1 providers.  This would, for example,
             allow the super-user to overwrite the MBR on the root disk or
             write random sectors elsewhere to a mounted disk.  The
             implications are obvious.


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## Alain De Vos (Nov 26, 2022)

if netbsd-slicing is unknown to freebsd you must write to the partition with an offset corresponding to the correct slice.


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## Emrion (Nov 26, 2022)

Something tells me that your command will make a non bootable SD card.
What are you trying to achieve?


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