Hi Suzan,
There can be different causes for your issue:
- The image you are using is not made to boot from SD. Normally, the uboot images are made to boot from NAND, if you want to boot from a different source, you have to modify the code. You can try to download it to NAND and see if it boots from there.
- Your boot pins are not correctly configured. Please check tables 7-1 and 7-3 of the MX25 reference manual and make sure your pins are correctly configured to boot from the source you want.
- Your serial port is not correctly configured. So your system is actually booting but you can't see anything in your console. Settings are: Baud rate: 115200, Data: 8 bits, Parity: None, Stop: 1 bit, Flow control: None.
Best regards.
Jorge.