I think there may be an error in the IMX6Q reference manual regarding one of the boot configuration pins.
From the IMX6Q reference manual page 269 pin EIM_EB3 is linked to boot configuration BOOT_CFG3. Other pages also reference this (Table 4-2 page 327), Page 1974 IOMUXC_SW_MUX_CTL_PAD_EIM_EB3_B field descriptions.
However Table 8-3 on page 384 states EIM_EB3 is linked to BOOT_CFG4.
BOOT_CFG4 makes more sense as it is linked to the infinite loop test, whereas BOOT_CFG3 is reserved.
Which is correct?