Trying to boot imx6 from SPI-NOR-Flash...

[EdSutter]

I installed an SPI flash device on the iMX6-smart-devices board and have a working interface to that.

I am currently booting/rebooting my board over USB using the imx_usb tool.  Now I want to transition

a usb-based boot to SPI-boot.  First, I have to reconfigure the BT_CFGX bits, and then it appears to me

that I can use the exact same image I boot over USB as the boot image for SPI-flash, true?

[EdSutter]

Adding text to my question, which explains why we are not able to boot from SPI

NOR Flash.  This experiment uses the iMX6-SABRE Smart Devices Board.

The SPI Flash device (U14 on the schematic) is not populated.  We populated the

device and I was able to interface with it at runtime (so that I could load it up with a

boot image).

The next step was to reconfigure the BOOT DIP switch and BT_CFG4 pins to use this

device as the boot device.  This is where the trouble started.  After a day of not seeing

the signals I expected to see (at boottime) on the device, we realized that the ROM

bootloader has the IOMUX configuration to use a different set of pins for ECSPI-1 boot

(refer to table 8-25 of reference manual).

Despite this problem, my question still holds: is the image format for a serial boot over USB

the same as the image that would be stored in a SPI-boot device?

[EdSutter]

For anyone looking for some empirical data on this, I can confirm that when booting off ECSPI5 on the smart devices board, I was able to use the exact same u-boot.bin file for booting off SD, USB or SPI-NOR.

[maheshmahadeva1 · Accepted solution]

The important thing needed during boot from a storage media s to ensure that the bootloader has an Image Vector Table (IVT), this is used by ROM during Boot from a storage media.

If your image is downloaded using the imx_usb tool and has a an IVT, then the same image might work.

The reason I say might is because the IVT might not get exercised in Serial downloader mode (USB download). So you might see problems if the IVT is faulty when booting from SPI-NOR.

[EdSutter]

Ok, thanks.  I guess I'll just have to wait till I have hardware that allows me to prove it in.