Linux/AM3354: Flashing images to eMMC in UART boot mode

Mehmet,

UART is usually considered to be too slow for this type of operation. USB or Ethernet are usually preferred. Is one of these more appropriate for what you want to do?

The information that we do have available is here:

software-dl.ti.com/.../Foundational_Components_U-Boot.html

It is a pretty simple use of the X-Modem protocol to send files over UART.

I hope this is helpful to you.

Dear Ron,
Could you tell me how to write SPL and uboot to eMMC via USB flash after booting uboot from uart?

Thanks

Mehmet,

So, you can boot to a U-boot prompt from UART and you want to copy the files from a Flash Drive (AM335x is USB Host) to eMMC? Or, were you looking for something else?

Thanks,
Ron

Ron,

Yes, that's exactly what I want to do.

Could you tell me how to do it?

Thanks

Mehmet,

Please see:

software-dl.ti.com/.../Foundational_Components_U-Boot.html

Specifically section:

software-dl.ti.com/.../Foundational_Components_U-Boot.html

Instead of booting from the USB stick, copy the files from the USB stick to the eMMC, in the appropriate place. This can all be done, as the document illustrates, from a U-Boot prompt. It is very similar to copying files from a SDCard.

I hope this is helpful to you.

Ron,

In the first reference link you sent, it explains how to partition the eMMC.
However in order to write MLO, u-boot.img to eMMC and booting from it, don't we need ot write them to boot partition, if so how can I do it properly? Writing MLO and u-boot to rootfs does not work as expected.

Mehmet,

Can you please share the errors that you are getting?

Once you have partitioned and formatted the eMMC for a FAT filesystem, U-Boot should be able to see and navigate it much like any other filesystem.

Please see the "fat" commands in U-Boot using the help command.

Ron,

On the link it shows how to create rootfs, is this the only partition I must have?

U-Boot # printenv partitions
uuid_disk=${uuid_gpt_disk};name=rootfs,start=2MiB,size=-,uuid=${uuid_gpt_rootfs}
U-Boot # setenv uuid_gpt_disk ...first uuid...
U-Boot # setenv uuid_gpt_rootfs ...second uuid...
U-Boot # gpt write mmc 1 ${partitions}

Ron,

I have managed to write MLO and u-boot.img to emmc with below commands after partitioning as described on my previous comment.
Right now I am able to boot from eMMC to uboot. How can I proceed with kernel? when I try 'run mmcboot' I get;

switch to partitions #0, OK
mmc1(part 0) is current device
SD/MMC found on device 1
Failed to mount ext2 filesystem...
** Unrecognized filesystem type **

When I also try fstype, I get;
=> fstype mmc 1
Failed to mount ext2 filesystem...
** Unrecognized filesystem type **

How can I fix and boot to kernel?

Regards

Mehmet,

You've created the partition, but have you formatted them to a valid Linux filesystem (ext2, ext3, ext4, etc.)?

Thanks.