Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: splite on April 10, 2015, 05:28:47 PM

Title: MicroSD and SD Card max capacity
Post by: splite on April 10, 2015, 05:28:47 PM
Hello,

I could not find this info either on the wiki or in the A20-OLinuXino-Micro PDF doc.

Does anybody knows the maximum capacity for the MicroSD and SD card capacity ?

Thanks

Florian
Title: Re: MicroSD and SD Card max capacity
Post by: JohnS on April 10, 2015, 05:38:13 PM
May well be 32GB

Might be on the linux-sunxi site or in one of the AW data sheets.

John
Title: Re: MicroSD and SD Card max capacity
Post by: splite on April 10, 2015, 05:53:36 PM
I looked at https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A20-PDFs/A20%20Datasheet%20v1.0%2020130227.pdf

The datasheet says "support from 1Gb to 128Gb SD/MMC" but the A20-OLinuXino-MICRO is sharing the processor as the A20-OLinuXIno-LIME2   whose the doc says up to 32Gb.

May somebody from Olimex confirm ?

Thanks
Title: Re: MicroSD and SD Card max capacity
Post by: jmyreen on April 10, 2015, 07:53:22 PM
Quote from: splite on April 10, 2015, 05:53:36 PM
The datasheet says "support from 1Gb to 128Gb SD/MMC" but the A20-OLinuXino-MICRO is sharing the processor as the A20-OLinuXIno-LIME2   whose the doc says up to 32Gb.

May somebody from Olimex confirm ?

Thanks

I'm not from Olimex and don't have a definite answer either. But I do know SDHC cards only go up to 32 GB -- after that you need an SDXC card, which supports sizes up to 2TB. The A20 user manual says "Support SDSC, SDHC, SDXC, MMC, RS-MMC card", so at least the hardware should support card bigger than 32 GB.

Note that SDXC cards are pre-formatted using the exFAT file system, which is problematic in Linux: this file system is patented by Microsoft, who wants money for a license to use it. Somebody has written a driver for Linux based on the details in the patent application. What's not published in the patent application is not public information. Because of the licensing requirement the driver can not be included in the mainstream Linux kernel.

An SDXC card can of course be reformatted with some other file system, FAT32, ext4, etc.
Title: Re: MicroSD and SD Card max capacity
Post by: rouvas on April 11, 2015, 09:37:23 AM
I have used a 64GB MicroSD with an A20 (not the lime edition) with no problems.
Title: Re: MicroSD and SD Card max capacity
Post by: splite on April 13, 2015, 10:58:05 AM
Good news ! I was looking for using the 64Gb. I did not know about the SDHC / SDXC.

Thank you