Linux/AM3352: Non-volatile eMMC partition

Harsh Patel35

Part Number: AM3352

Tool/software: Linux

Hello Team

I am using AM3352 ti processor I want to create a small one Mbyte partition of eMMC that can work as non volatile memory for me. So i can read/write system data anytime.

So please let me know how can we create this partition that keep storing even after power cycles and Re-flashing images in it?

Thank you,

Harsh Patel

over 7 years ago

0 Kemal R. Shakir over 7 years ago

TI__Guru 55345 points

Hello Harsh,

You already have that partition. It is called /dev/mmcblk0boot1. It is with read-only access by default. Before writing to that partition do echo 0 > /sys/block/mmcblk0boot1/force_ro to enable write access on it then later do echo 1 > /sys/block/mmcblk0boot1/force_ro to re-enable the read-only access.

Best regards,
Kemal

0 Harsh Patel35 over 7 years ago in reply to Kemal R. Shakir

Intellectual 330 points

Thank you for input...i will test and update

0 Harsh Patel35 over 7 years ago in reply to Harsh Patel35

Intellectual 330 points

Hello Kemal

Your inputs helped lot.

I want to create customized 1Mb partition at end of eMMC as shown in figure and want to use as not volatile memory. Also i want to read/write it from application and uBoot.

Is it possible? if yes than how can we do this?

Thanks again

0 Steve Kipisz over 7 years ago in reply to Harsh Patel35

TI__Genius 15510 points

You can use fdisk to partition the eMMC and create the 1MB partition at the end. Then you can use mkfs to make a file system so that you can read/write it.

Steve K.

0 Harsh Patel35 over 7 years ago in reply to Steve Kipisz

Intellectual 330 points

Thank you It will help...

0 Harsh Patel35 over 7 years ago in reply to Kemal R. Shakir

Intellectual 330 points

Hi Team

I have tested it and its working fine...

I have following questions:

1] Is it safe to use mmcblk1boot1 partition as non volatile memory?
2] Is there any chance to generate failure in the system due to custom data read/write operations?

3] Is there any way to write mmcblk1boot1 using addresses?

- using "dd" we need files like, $ dd if=input_file of=/dev/mmcblk1boot1 bs=1024 count=1, but want to store data using address of eMMC same like "mmc" command in uBoot

Waiting for your inputs...

Thanks again for your help

0 Steve Kipisz over 7 years ago in reply to Harsh Patel35

TI__Genius 15510 points

Hi Harsh,
1. I have used dd to write/read from the mmcblk1boot0. You just have to use skip/seek and know the offsets of where you write/read your files.
2. Can you clarify what you are asking?
3. I think you can only use the offsets from the beginning.

Steve K.

Processors

Processors forum

Linux/AM3352: Non-volatile eMMC partition