Lpc2000

--- In lpc2000@yahoogroups.com, "sig5534" <sig5534@h...> wrote:
> 
> Thanks sjo.  Exactly what I was looking for.
> 
> I'm trying to get your last method to would, using the attribute.  
> This is what I did for a test function:
> 
> void __attribute__((section(".data"))) IAP_Test( void ) {
>   U32 N;
>   N=IOPIN;
> }  // IAP_Test
> 
> When I make I get:
> 
> main.o(.text+0x150): In function `main':
> /cygdrive/d/GNUARM/Projects/Vader/main.c:96: relocation truncated 
to 
> fit: R_ARM_PC24 IAP_Test
> collect2: ld returned 1 exit status
> D:\GNUARM\bin\make: *** [vader.elf] Error 1
> 
> The line #96 in main is where I put the call to IAP_Test().  GCC is 
> taking the attribute, and seems to be doing something with it, but 
it 
> is giving me this relocation error.  I don't know what R_ARM_PC24 
is.
> 
> Do I need to allocate extra space for this in my startup.s file?

Nice trick of just locating the RAM function in .data.

With main() in flash and IAP_Test() in RAM, they are ~1GB apart, and 
a normal BL instruction can only handle distances of up to +/- 32 MB.
Try calling it indirectly:

static void (*pramfunc)(void) = IAP_Test;
(*pramfunc)();

Karl Olsen