USB support at u-boot

[manjunathjoshi]

Hello All,

I am seeing that u-boot - 2013.04 has support for u-boot but what are the prerequisites that are needed to make the boot possible from USB device? Does anybody have an idea?

U-Boot > usb start

(Re)start USB...

USB0:   USB EHCI 1.00

scanning bus 0 for devices... 1 USB Device(s) found

       scanning usb for storage devices... 0 Storage Device(s) found

       scanning usb for ethernet devices... 0 Ethernet Device(s) found

These are the logs found on my board even though i have connected USB stick on HOST1.

Regards,

Manju

[manjunathjoshi · Accepted solution]

Hello All,

The USB is connected to a hub and then to the processor. That is why i was not able to see the LED blinking or the storage device.

Now i am able to see in other similar board with no hub.

So if anyone using the USB, has to make sure that the lines are connected to i-mx directly since i-mx has dedicated USB port connection.

Regards,

Manju

[BiyongSUN]

Hi Manju,

uboot usb is supported since 3.10.17 bsp release.

But here is the concern. The usb stack in uboot is very old and weak.

lots of usb stick cannot be used. Most of them can not be used is new usb stick.

[fabio_estevam]

Hi Manju,

Just to clarify: mx6 does not boot from directly USB thumb. Is this what you are trying to achieve?

You need to flash U-boot in to one of the supported media: SD/eMMC, SPI NOR, SATA, etc.

The usb support command in U-boot allows you to connect USB thumb and you can read files from it, but you cannot boot U-boot from a USB thumb.

Regards,

Fabio Estevam

[manjunathjoshi]

Hello Fabio,

My intention is to boot the kernel and filesystem from u-boot prompt through USB. The board already has u-boot in eMMC.

Regards,

Manju

[sinanakman]

Hi Manju

What board is this ? Also, can you just try a more

recent (and preferably a mainline) u-boot version.

On my sabresd board, with mainline u-boot from

tip of the mainline tree, USB works fine.

Regards

Sinan Akman

[manjunathjoshi]

Hello Sinan,

Thanks for your reply. The board is custom one similar to SABRESD but has 2 USB hosts.

You are right. With mainline u-boot which i have, the USB is supported. I can see in the u-boot prompt. Apart from that what should i take care off in the source so that the USB device is detected.

The problem is, when i connect USB i see that power is not going to the device. We can see the USB LED blinking as soon as the kernel boots up but not at the u-boot prompt.

Regards,

Manju