Elan Doensen

Serial UART boot protocol on IMX25, what is the structure of an application image?

Discussion created by Elan Doensen on Nov 13, 2011
Latest reply on Nov 21, 2011 by Qiang Li - Mpu Se

We are using imx257.

The freescale ATK did was not reliable and refused to work with our imx257 board (The ATK passes the POS test). Thus I wrote a tool to use the "serial download protocol" to blow the fuses of our board and get it to a state that it could boot from MMC or SPI flash. It can also be used to read/write memory etc.

Problem is that if we blow the fuses on the imx to boot from SPI, if we ever mess up the SPI flash, we are left with a bricked unit. However when the SPI flash is messed up, the HAB on the imx defaults to "serial download protocol" and we can talk to it.

I need the ability to make the imx (using the serial download protocol) run an application (specficially a uboot image) that I can load into dram. I can then use that application to fix the SPI flash.

 

According to the imx257 documentation, it is possible to load and run an application via the serial download protocol. (Chapter 7.8). However I have tried to do this and have failed. Problem is I am uncertain what form the application image must take.Does it need a flash header? Does it need a DCD? How does it jump to the application when you download it? This is completely unclear from the imx manuals that I have.

Can anyone give some hints on how the application image should be structured for the imx to run it from the serial download protocol?

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