Add possibility to exclude certain devices

[philipgiuliani]

Problem
On a Raspberry the system sdcard is suggested instead of a external attached sd card.

Possible solutions

1. ~/.fwup.conf file with a list of interfaces to exclude/include
2. ~/.fwup.conf which allows to set all the defaults of the argument i can pass (so i dont have to specify -d everytime)
3. Maybe the auto-detect feature should show all attached sd cards and you can set a default (which than would write the config):

Which memory card would you like to use (press d to set as default)?
[*] 29.72 GiB at /dev/mmcblk0
[ ] 7.14 GiB at /dev/sda

[fhunleth]

@mobileoverlord - FYI: this issue may affect the Nerves tooling. I'm still thinking of a solution. The backstory to this issue is that @philipgiuliani is running on a Raspberry Pi where the SDCard containing the OS looks a lot like an SDCard that fwup would like to program. Use of a configuration file came up while we were brainstorming possible solutions. I'm currently leaning towards being smarter with the auto-detect logic for this situation. That doesn't mean there wouldn't be a conf file, though. Also, I believe that we're swapped in how we ask the user to proceed. fwup defaults to not burning an auto-detected SDCard, and mix firmware.burn defaults to burning. We should probably make it consistent.

[GregMefford]

You could process the output of df to ignore the drive that's mounted at /.
I was thinking you could ignore anything that's in df, since the person wouldn't be mounting their SD card, but that's probably not as robust with Linux auto-mounting USB drives.

[fhunleth]

@philipgiuliani: I added detection of which drive is mounted at / to exclude it from the autodetect list. It's in the autodetect branch. Could you try it out? You can get a prebuilt .deb package for Raspbian here: http://files.troodon-software.com/fwup/autodetect/fwup_0.9.2-dev_armhf.deb. It will install fwup to /usr/bin, so if you've previously compiled from source, be sure to remove the one in /usr/local/bin.

[philipgiuliani]

@fhunleth I'm not at home, i'll try it out today evening.

[philipgiuliani]

It seems to have worked fine.

pi@philipdev:~/workspace/gardex/apps/fw $ mix firmware.burn
Use 3.69 GiB memory card found at /dev/sda? [Yn]

Awesome, thanks! :)

[fhunleth]

Great! Thanks for verifying. I'll merge the change to master for the next release.

I'm going to keep this issue open a little bit longer since the config file is still interesting. It has some ramifications, though, that need thought. If I don't get any great ideas before the next release, I'll close this and possibly open an issue solely regarding the config file.

[fhunleth]

I'm closing this issue, since I'm pretty sure that the original problem has been addressed. I'm not opposed to having a global config file, but I don't feel like there's enough motivation to spend time adding it (for me at least).