bootloader vs sdram stm32f429

I'm designing a board that uses the micro stm32f429 . I am considering to use the bootloader CAN integrated and at the same time a memory SDRAM using the FMC . I'm in trouble because the pin PB5 is the CKE pin of the SDRAM and also the rx pin of can2 used in bootloader . There is no possibility to remedy the problem or is it impossible to use the bootloader in CAN bus mode with a SDRAM memory?