GUIDE How to Enable eMMC and MMC Cards on macOS

How to Enable eMMC and MMC Cards on macOS​

This guide covers enabling eMMC and MMC Cards on macOS using Clover and OpenCore. By following this guide, you'll be able to enable eMMC and MMC based storage devices on macOS using Clover or OpenCore Bootloader.

Overview​

Embedded Multi-media Card (eMMC) is a non-volatile memory system that combines flash memory and a flash memory controller into a single silicon die. Usually, soldered on the motherboard, which is where the embedded part of the name comes from. It's a primary storage for portable devices like cell phones or tablets and even some notebooks.

eMMC is the latest format of the MultiMediaCard and is being widely adopted for portable devices. However, the disadvantage of such storage technology is if it fails, the eMMC would need to be replaced or repaired, which isn't an easy task as it involves the SMD and reflow techniques to remove the soldered chip and then replace and/or repair with a new one.

Unlike the standard M.2 (SATA/NVMe), which can provide up to 600MB/s Read and 500MB/s Write, the NVMe (Gen3) goes up to 3500MB/s Read and 3000MB/s Write. Whereas NVMe (Gen4) is capable of 7000MB/s Read and 6500MB/s Write speeds, the eMMC (5.1) can do a max of 250MB/s Read and 125MB/s Write speeds.

Despite the lower speeds, it is still widely used in consumer electronics as a primary means of integrated storage and boot ROM in portable devices. This helps the manufacturer to lower the manufacturing cost to an extent where the performance isn't needed much, aiming to manufacture as slim as possible.

Although Apple never used eMMC and MMC cards on their Mac lineups, non-Apple computers can be often found with eMMC (such as HP C621 Chromebook). Before this, it wasn't possible to use such eMMC and MMC cards on macOS. As these devices have the eMMC as a primary storage device, there isn't an option to replace the eMMC with a larger capacity, and even if you proceed with upgrading the eMMC, that voids your system warranty, which may not be feasible for most of the users out there. In addition, there are rare computers that also have an option to add an M.2 (SATA/NVMe) to the system. Therefore, the user is left with only a few options: (i) replace the eMMC with a larger capacity, (ii) replace the system with a system that has a standard storage option, and; (iii) use a driver to make the eMMC functional on macOS and that's the best option if you're not comfortable with the other two options.

Please note that this driver is currently a work in progress and for some eMMC and MMC chips, you may experience poor performance or even encounter the device to be nonfunctional on macOS. In addition. SD cards are currently not supported at this time.

Requirements​

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Following are the requirements for enabling eMMC and MMC Cards on macOS. Please ensure you meet the requirements before proceeding with this guide.

Storage Hardware	eMMC/MMC. See Storage Compatibility for more information.
macOS	macOS High Sierra and Later.
Bootloader	Clover or OpenCore. Please ensure to use the latest version to avoid issues.
Kexts	Lilu EmeraldSDHC
Tools	IOReg OCAT or any equivalent .plist editor

To enable the eMMC support, you'll need to add EmeraldSDHC.kext along with the Lilu.kext. These two kexts are needed together to work in conjunction to enable the eMMC cards on macOS.

1. Download Lilu.kext and EmeraldSDHC.kext.
2. Mount your ESP.
3. Unzip the kexts from the RELEASE directory.
3. Depending on your bootloader,

For Clover:​

If you're using Clover, copy Lilu.kext and EmeraldSDHC.kext to the EFI/Clover/Kext/Others directory.

For OpenCore:​

1. If you're using OpenCore, copy Lilu.kext and EmeraldSDHC.kext to the EFI/OC/Kexts directory.
2. Open your config.plist and add Lilu.kext and EmeraldSDHC.kext entries in the Kernel>Add section of your config.plist.

4. Restart your system. It is recommended to reset NVRAM twice at least.

Now you can boot the macOS installer to install macOS on the eMMC and boot off via eMMC.