iMx6 BOOT_CFG4[6] Recovery Devices

[yannickc]

Dear,

In reference manual section 8.9 it says that if BOOT_CFG4[6] fuse is set, "the chip supports recovery devices".

What does it mean exactly ?

If no valid U-Boot is found it try to load on recovery SPI flash ?

or if BOOT_CFG4[6] is set it forces load on recovery SPI flash even if valid U-Boot is in primary device ?

Is BOOT_CFG4[6] GPIO is taking into account in internal boot mode instead of eFuse ?

Thanks in advance for you help.

Yannick

[igorpadykov · Accepted solution]

Hi Yannick

if no valid U-Boot is found it will try to load on recovery SPI flash,

if Uboot is valid it will boot from primary device.

By default If no valid U-Boot is found it try to load from USB -

Serial downloader (USB OTG). From sect.8.9:

"If primary boot device fails, boot ROM will try to

boot from recovery device using one of I2C or ECSPI ports."

Best regards

chip

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

[petertaylor]

chipexpert,

Is SPI Flasth the only option? 

Would it be possible to try booting from eMMC on USDHC-3 and if there's no image, try booting from microSD on USDHC-1?

Thanks,

Peter

[igorpadykov]

Hi Peter,

For i.MX6DQ there is no such option.

For i.MX6SDL, i.MX6SDL Reference Manual (rev.1  5/2013)

sect.8.11 "SD/MMC Manufacture Mode":

"When internal boot and recover boot (if enabled) failed, boot will go to SD/MMC

manufacture mode before serial download mode. In manufacture mode, one bit bus width

is used despite of the fuse setting.

In manufacture mode, SD or MMC card will be scanned on uSDHC1 and uSDHC2."

http://cache.freescale.com/files/32bit/doc/ref_manual/IMX6SDLRM.pdf

Best regards

chip

[yannickc]

Thank you chip it's clear for me now.

Yannick