After installing ua-netinst, on a Pi 3 model B v1.2, I get a rainbow screen.

From the comments here, this is expected and I need to re-copy the start.elf, start_cd.elf, start_db.elf and start_x.elf file to the SD card.

The only problem is that the process (during first boot on the Pi) involves re-formating the SD card into two partitions; a FAT16 system for the above files and an MBR system for linux.

Unfortunately my windows box will not let me edit the FAT16 partition. I can see the files using DiskInternals Linux Reader, however.

How can I put files onto the FAT16 partition of a microSD card?


After first boot (during which SD card is reformatted), if I try to access the SD card with windows I am initially greeted with this:

You need to format the disk in Drive E: before you can use it

If I cancel this, and use Linux Reader, I can see the disk partitions and FAT16 files but I cannot edit/replace the files.


Below is an image showing what I see in the Linux-Reader application, having selected properties on Volume 1:

enter image description here

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    The SD card should already have two partitions, and the FAT one should show up as a drive named boot. Have you checked Disk Management if it's mounted? Some drives have to be mounted manually for whatever reason. – PNDA Jul 6 '16 at 2:09
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    You're confused. FAT16 is a filesystem type used on a device partition and "MBR" stands for master boot record, which is a description of the partitions on a device. It is not any kind of partition or filesystem, and further, it is generally required in order for you to have any partitions at all (including just one, although there is also a much less common way of formatting an entire device as "partitionless" with a filesystem on it). – goldilocks Jul 6 '16 at 8:41
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    Up until recently (when it was supplanted by GPT) MBR (which as per that wikipedia article, began with DOS) was also more or less the only choice in this regard on normal consumer PCs, and it is still the one used almost exclusively on things like USB sticks, SD cards etc., regardless of context. If you are using ua-netinst you are going from an MBR formatted device with one FAT32 partition to one with two partitions, one FAT32 and one ext4. This modifies the MBR, it does not add it, and, again, an MBR is not a partition. It's a 1/2 kB of information at the start of the device. – goldilocks Jul 6 '16 at 8:42
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    Yeah, that is confusing/ambiguous. By "linux native" it means an ext4 partition; by "MBR partition" it presumably means this is on an MBR style device (for consistency, it should say the same thing about about the FAT16 partition). – goldilocks Jul 6 '16 at 9:09
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    The whole FAT16 thing seems a bit fishy as I've only ever seen this partition described as FAT32, although since it is small it's probably irrelevant as long as it uses "vfat" extensions to allow long filenames -- even that may not be necessary since the critical stuff all fits into an 8.3 format (as in, <= 8 characters dot 3 character suffix, eg. start.elf). I'll try to put more about this into an answer. – goldilocks Jul 6 '16 at 9:09

After installing ua-netinst, on a Pi 3 model B v1.2, I get a rainbow screen.

This may be because the card has just not been done right from the beginning, although if it ends up changed something is going on. Maybe.

If, after you prep the card, insert it for the first time, and power on the pi, you see the green ACT light flickering intermittently, then it is booting and presumably ua-netinst is doing its thing.

If instead you just see the green ACT light on solid or not at all, the card is not properly formatted and nothing is happening.

From the comments here, this is expected and I need to re-copy the start.elf, start_cd.elf, start_db.elf and start_x.elf file to the SD card.

I would regard those comments a little bit like directions you might get on the sidewalk late at night from someone stumbling drunk. This person may or may not have any idea what they are talking about, but it certainly reads like a blind guess (keeping in mind there is such thing as "dumb luck"). And/or I'm not so sure the context the comments are made in are what you are assuming they are.

You should not have to do anything beyond what is explained here:

Format your SD card as FAT32 (MS-DOS on Mac OS X) and extract the installer files in.


  • Format the card.
  • Unzip the ua-netinst zip file.
  • Copy everything from the zip file onto the FAT32 formatted card.

Then go to this step, which does include "cross your fingers" in the description.

Beware that while ua-netinst should work with the Pi 3 since it is (presumably...) just installing the latest Raspbian over top of itself, the last time ua-netinst was updated was before the Pi 3 was released, and there are some files required to make the 3 work specific to it that need to end up on the first partition. If that isn't happening, you will have problems.

Also beware that ua-netinst is I think at best "cross your fingers" friendly from a complete novice perspective. Your life will be much, much, much easier if you can get access to an HDMI display and keyboard for an evening and just install Raspbian the normal way. You learn to walk before you run and all that.

  • Unfortunately the "crossing fingers" approach to ua-netinst installation on Pi3 doesn't work... Which lead me to the "drunken sidewalk comments". What I've seen so far matches their description - I just need to copy the .elf files to the FAT partition of the SD card (if that is possible). I do have a working SD card image. However, I'm going for ua-netinst as I'm aiming for an Eth(Embedded) install. – atomh33ls Jul 6 '16 at 9:58
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    If your problem still boils down to how to copy files onto a FAT16 partition using MS Windows, it really has zilch to do with the Raspberry Pi, and you would be better off asking on our larger sibling site Super User -- which is why I am closing this question. Not to be mean, but to save you wasting more time. Why you need to copy files to a FAT16 partition doesn't matter. Just ask "How do I copy files onto a FAT16 partition using Windows?" – goldilocks Jul 6 '16 at 10:03

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