Lpc2000

I had a problem when I moved to a Cygwin hosted GNU build (using a 
Phycore 2294).

The hex files downloaded correctly but did not appear to run on the 
target. Strangely, the problem was being caused by the order in 
which the startup code was structured.

If my startup code was as follows, the file jumped into 
the "undefined" vector loop:

<--BEGIN CODE-->
Vectors:
        b     _start                    // reset - _start
        ldr   pc,_undf                  // undefined - _undf
        ldr   pc,_swi                   // SWI - _swi
        ldr   pc,_pabt                  // program abort - _pabt
        ldr   pc,_dabt                  // data abort - _dabt
        nop                             // reserved
        ldr   pc,[pc,#-0xFF0]           // IRQ - read the VIC
        ldr   pc,_fiq                   // FIQ - _fiq

_undf:  .word __undf                    // undefined
_swi:   .word __swi                     // SWI
_pabt:  .word __pabt                    // program abort
_dabt:  .word __dabt                    // data abort
_irq:   .word __irq                     // IRQ
_fiq:   .word __fiq                     // FIQ

__undf: b     .                         // undefined
__swi:  b     .                         // SWI
__pabt: b     .                         // program abort
__dabt: b     .                         // data abort
__irq:  b     .                         // IRQ
__fiq:  b     .                         // FIQ

_start:
// Startup code here

<--END CODE-->

But if I moved the exception loops to below the start code (shown 
below), then everything seemed to work fine.


<--BEGIN CODE-->
Vectors:
        b     _start                    // reset - _start
        ldr   pc,_undf                  // undefined - _undf
        ldr   pc,_swi                   // SWI - _swi
        ldr   pc,_pabt                  // program abort - _pabt
        ldr   pc,_dabt                  // data abort - _dabt
        nop                             // reserved
        ldr   pc,[pc,#-0xFF0]           // IRQ - read the VIC
        ldr   pc,_fiq                   // FIQ - _fiq

_undf:  .word __undf                    // undefined
_swi:   .word __swi                     // SWI
_pabt:  .word __pabt                    // program abort
_dabt:  .word __dabt                    // data abort
_irq:   .word __irq                     // IRQ
_fiq:   .word __fiq                     // FIQ

_start:
// Startup code here

__undf: b     .                         // undefined
__swi:  b     .                         // SWI
__pabt: b     .                         // program abort
__dabt: b     .                         // data abort
__irq:  b     .                         // IRQ
__fiq:  b     .                         // FIQ

<--END CODE-->


I have no explanation for this but it worked for me (after a couple 
of days of head-scratching). If anyone can explain why this is the 
case I would love to know!?!?

Hope this helps,

David


--- In lpc2000@yahoogroups.com, "Richard Rauscher" <richard@m...> 
wrote:
> I've moved from the Keil uVision3 to a linux hosted GNU build 
using the
> exact same linker script.  Here are the two pertinent targets from 
the
> Makefile, one for linking and one for creating the hex file (which 
I then
> download from my windows system with Philip's LPC210x_ISP utility).
>  
> 
> 		FW.elf : $(SOBJS) $(COBJS)
> 		    $(LD) -o FW.elf $(SOBJS) $(COBJS) $(LIBPATH) -
lc -lgcc -T Target.ld
> 		 
> 		FW.hex : FW.elf
> 		    arm-elf-objcopy -O ihex FW.elf FW.hex
> 
> hth,
>  
> --rich
> 
> ________________________________
> 
> From: Charles Manning [mailto:manningc2@a...]
> Sent: Sat 10/23/2004 9:18 PM
> To: lpc2000@yahoogroups.com; peterburdine
> Subject: Re: [lpc2000] Programming GNU hex files
> 
> 
> On Saturday 23 October 2004 03:42, peterburdine wrote:
> > I seem to be having problems trying to program my Phycore LPC2994
> > module when I use the GNU toolset.  I have tried using both JTAG 
and
> > the Philips utility, and neither of them will successfully 
program the
> > chip.  It will instead have the the previous program.  If I used 
the
> > Keil toolset I do not have this problem.  Does anyone have any
> > suggestions?  I am using uVision 3.
> >
> > Thanks,
> > Peter
> 
> This is most likely something to do with either your start up file 
or your 
> ldscript.
> 
> Have a look at the two map files and see how they differ, that 
should give 
> some clues.
> 
> -- CHarles
> 
> 
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