When you replace CD/DVD with SSD and want to update firmware of yours SSD, but can neither burn ISO, downloaded from official website, nor boot from this CD..
Even you have created from ISO boot usb stick – Mac does not see when pressing Alt while booting – it needs UEFI boot loader.
Prepare USB Drive:
Connect yours pendrive.
Open terminal window.
Determine which device it use in system. In Linux it will be sdX , in OSX – diskN
df -h /dev/sdX1 1,4G 1,4G 0 100% /media/user/Transcend8G
then unmount ( do not eject! ) usb drive
sudo umount /dev/sdX1
Download UEFI usb stick image with Crucial Firmware updater M0CR050 (from 16 May 2017 )
(version M0CR040 from 1 Nov 2016 )
Write image to yours USB drive
Caution! Be careful!
1. You should write to drive (sdX/diskN), not to partition (sdX1,diskNs0)
2. If you specify wrong device – you WILL destroy your OS or data!
sudo dd if=uefi-crucial-mx300-M0CR050-usb.img of=/dev/sdX bs=1M
Now you can mount it back.
Check for latest Crucial SSD firmware at http://www.crucial.com/usa/en/support-ssd-firmware
If it have new version – download it , unpack, open downloaded fimware ISO and replace
/boot and /cde folders on USB drive.
Your UEFI USB Drive is ready to use.
Boot your mac with Alt key pressed and choose UEFIBOOT drive.
You will see two menu options:
* Micro Core Linux with waitusb=10 and superuser
* Micron Storage Director FW update
Choose second one for FW update – and relax.