Posted on May 17, 2011 at 13:00I have the above CPU and with a customized boot loader based on the USART/YMODEM example, except it pulls the code from a serial data flash part. This works just fine.
I have an application that uses a 128x64 display. When I load in a font with just the chars from 32 to 127, my application runs fine. But, if I expand the font to chars from 32 to 255 to include the foreign (to me, anyway) characters, my application fails to start. I have checked, and my ROM usage is not exceeding the part's capacity. What I have traced out in the debugger is this.
When I build the application with the larger fonts, the application start vector at 0x08002000 + 4 is 0x0800ec81. This is my application's __iar_program_start address. Tracing through this it calls __low_level_init, then __iar_data_init2 then __iar_zero_init2 then it calls __iar_rle_init2. Something in this call must go wrong, because instead of exiting this function, instead I get a hardware exception (which puts me in an infinite loop in the exception handler, which is the default).
When I build with the smaller font data, the __iar_program_start address is lower and everything works just fine.
None of the actual code changes, only the addresses of where the code lives, moved because of the addition of the const arrays of character data.
Any idea of what could be going wrong?
TIA,
Jeff
