I am trying to configure a fresh iMX6DL to make it boot from an eMMC 4.4+ connected to uSDHC1 in 8-bit DDR mode. Unfortunately it doesn't work.
The BOOT_MODE[1:0] are pulled to 00.
BOOT_CFG1 is set to 0x60 (eMMC)
BOOT_CFG2 should be 0xc0 (8-bit v4.4, SD1) but it is c8 (8-bit, v4.4, SD3) as this selection for uSDHC3 is already present when I pick a new iMX6 from the shelf...
And an additional problem may be, thatthere is used DS1_DAT0..SD1_DAT3 in normal SD-D0..3 configuration but NANDF_D0 to NANDF_D3 ind alternate config for SD-D4..7 to access the eMMC databus.
However, the boards support a local SPI NOR flash, and for a fallback... Is it possible to flash the BOOT_CFG1 that has 0x60xx to a value that supports again SPI NOR boot, or is there any other option to fall through to ECSPI1 even there is an eMMC without a valid boot sector?
I'd like to recover the boards in case booting from SD1 is not possible.
A big bonus would be, if the BOOT_MODE pins still enable to pull the board in USB download mode, as this enables fallback in case of a destroyed u-boot.