My problem was that I wanted to install NOOBS on a new 128 GB SD card using my Mac, and I didn’t want to download yet another random piece of software to reformat the card from exFAT to FAT32 when the Mac has perfectly functional tools already installed and just itching to be put to use. Nor did I want the pain of trying to use dd to copy over a Raspbian image. Which, in retrospect, probably would have been easier.

In my attempts to get this working, I failed several times. The symptoms of having the card incorrectly formatted are that when you attempt to boot, the Raspberry Pi does not send any output to the HDMI connection, and the green LED (activity indicator) endlessly repeats a 4 blink cycle while the red LED (power indicator) remains steady. The Pi is not broken. It’s just complaining that it can’t read the card.

This is how to fix it.

Plug in your SD card to your Mac using a card reader and then:

$ diskutil list

The above command will display a list of all your drives, and you can use that information to determine which is your SD card. This is what mine looked like:

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *127.9 GB   disk2
   1:               Windows_NTFS                         127.8 GB   disk2s1

WARNING: make sure you know exactly which disk is your SD card. If you get this wrong, I can pretty much guarantee that you will have a Very Bad Day. If you aren’t 100% certain: Stop. Google. Come back when you’ve smarted up some. Or when you’re ready to spit in the devil’s face and accept the consequences.

$ diskutil partitionDisk disk{x} MBR FAT32 RASPBIAN R

The above command will reformat your SD card if you replace “{x}” with the number of your disk. Yes, I left off the disk number, because I’m not going to accept responsibility for your blind copy and paste hackwork.

After I completed this step, my card format looked like this:

$ diskutil list disk2
/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                        *127.9 GB   disk2
   1:                 DOS_FAT_32 RASPBIAN                127.9 GB   disk2s1

At this point, I simply dropped the NOOBS files onto the card, and boom!

Okay, Google, the information is here. I’ve done my part. Now do yours.