Friday, July 26, 2013

SamSung SSD 840 firmware upgrade on Mac without Bootcamp or Internal Superdrive

Situation

I replaced my internal superdrive with a Samsung 840 SSD in a HD caddy.  Then I put the superdrive in an external USB exclosure so I could simply attach the device for the very few times I need to read a DVD or CD-Rom.

Aside from the 1TB HD, I now also have a SSD that is used a boot disk and contains Mountain Lion and a bunch of applications.  Data is stored on the slower hard disk.

Problem

My Mid-2010 iMac does not allow to boot from the external superdrive.  When you try, you are quickly presented with the message that it could not find a bootable device, press a key to retry...
Because Samsung provides its SSD firmware update for Mac by a bootable ISO you have to burn to DVD, I was stuck.

I did not want to install Windows with Bootcamp, just for updating my SSD firmware.  And even if I would have wanted, it probably wouldn't work since I can't boot a DVD from my external superdrive.

Some more info about the Samsung SSD firmware

It appears that the DXT08B0Q_Mac.iso file from the Samsung download site contains just a single file: BTDSK.IMG, which is just an image file containing FreeDOS and an SSR directory with the actual firmware (SSR/FW/DXT08B0Q/DXT08B0Q.enc) and an update utility (DSRD1_0.EXE).

Simply putting the image file on a USB stick didn't work.  It was not found by the EFI boot manager of my iMac.

Workaround

So I needed to find a way to be able to boot FreeDOS and run the DSRD1_0.EXE to do the update.

That was where rEFIt came into the picture, which is an EFI boot manager that is more advanced that the standard EFI environment that comes with a Mac (which appears to be an EFI 1.x environment).

And I needed a FreeDOS image I could boot from rEFIt.

I didn't want the struggle attaching external devices, so I added 2 partitions to my internal HDD:

  • A HFS+ partition for rEFIt that can boot SYSLINUX
  • A FAT partition for SYSLINUX (needed to boot FreeDOS)

Procedure

Download the required tools and firmware:

Create the extra partitions with Apple's Disk utility:
  • first create a 1G partition with an Apple extended journaled file system for rEFIt, so call it rEFIt for clarity
  • then create a 1G partition with a FAT file system for SYSLINUX and a FreeDOS image, just make sure that this partition is within the first 3 partitions (so make sure it is a primary partition), or you won't be able to boot from it.  Name it SYSLINUX
Setup rEFIt:
  • Open the rEFIt-0.14.dmg image that you downloaded from the rEFIt site
  • Copy the "efi" directory to newly created rEFIt partition
  • Open a command shell and go to /Volumes/rEFIt/efi/refit/ to run the enable.sh script
    • cd /Volumes/rEFIt/efi/refit/
    • sudo ./enable.sh
Get a bootable FreeDOS image from the UNetbootin site and install it:
  • Run the app, provide the superuser password
  • Choose "FreeDOS" as the distribution (version 1.0 at this time)
  • Type: USB drive
  • Drive: /dev/disk0s4 (or whatever the device you have you SYSLINUX partition on, check with diskutil list)
  • It will download FreeDOS and install it on the partition
Next, prepare the firmware:
  • Open de iso file, you will find a BTDSK.IMG file
  • Open de BTDSK.IMG file, and copy the SSR directory to the SYSLINUX partition, so that you can access the firmware once you have booted in FreeDOS.
Reboot, and press the Option key while hearing the "BOING" sound at startup to boot FreeDOS:
  • Choose to boot SYSLINUX (rEFIt)
  • Choose the default kernel
  • Choose 5 to boot FreeDOS Live
  • Once you get the A:\> prompt, change to C:
    • C:
    • cd SSR
    • run DSRD1_0.EXE
  • Follow the install utility
  • In my case, I had to power cycle the SATA SSD, but I couldn't since it was internally, so the version check failed and it said it was unsuccessful.
After a reboot, the firmware version will be refreshed with the newest firmware version.