Transition from RAM to FLASH: CFG file and chip selects

[Haiiro]

I have the system working well in RAM when using the debugger. I can target the flash memory and program it with the flash programmer. However, the system will not run from flash very long at all.

The main problem seems to be that in debugger mode, the chip selects are set up in the CFG file. This procedure does not exist when running from flash, so it is missing the RAM chip selects.

What is the preferred method of setting up the chip selects at the beginning of runtime when running from flash?



Message Edited by Haiiro on 2008-03-07 10:25 AM

[Haiiro]

The system is an MCF5235, CW 6.4.

However, we may have found out what is happening.

This project was started out on the eval board. I started out using an example from the operating system vendor - it seemed like the right idea at the time, and this was my first project using CodeWarrior.

We had figured out that the chip selects were not being set up, but we were not sure about the best way to add that initialization code.

A service request to Freescale brought up the issue of hwinit.c. While this code is in the project, it was called too late to make a difference. However, I went to look at it in the stationery example in:

C:\Program Files\Freescale\CodeWarrior for ColdFire V6.4\Stationery\ColdFire\CF_M5235EVB\C\CF_M5235EVB_C.mcp

In ROM-UART settings -> Linker - > ColdFire Linker -> Entry Point
you will then see exactly what is going on. The entry point is set to _asm_startmeup instead of _start. Do a search for _asm_startmeup and you will find it in "mcf523x_lo.s"

This contains the chip select initialization code that is effectively missing in my project. This generally went unnoticed because my project was derived out of the operating system example project instead of the CodeWarrior stationery project.

[RickN]

What is the MPU?

- Rick