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pointer problem
- From: John Gonzaga <jgonzaga at pnicorp dot com>
- To: "'gcc-help at gcc dot gnu dot org'" <gcc-help at gcc dot gnu dot org>
- Date: Fri, 13 Sep 2002 09:36:03 -0700
- Subject: pointer problem
We just got our boot code running and I'm trying to make a simple C++
program. But here's my problem:
#define REGBASE 0x3FF0000
#define IOPDATA (REGBASE+0x5008)
// LED class
class LED
{
public:
LED( unsigned long * );
...
}
... in main
// This code will not work
unsigned long * ioport = ( unsigned long * )IOPDATA;
LED * pLED = new LED( ioport );
// ... but this works!
LED * pLED = new LED( ( unsigned long * )IOPDATA );
Looking at the dump for the code that doesn't work.
unsigned long * ioport = ( unsigned long * )IOPDATA
10001d4: e3a03008 mov r3, #8 ; 0x08
10001d8: e28337ff add r3, r3, #66846720 ; 0x3fc0000
10001dc: e2833a35 add r3, r3, #217088 ; 0x35000
10001e0: e50b3030 str r3, [fp -#48]
LED * pLED = new LED( ioport );
10001e4: e3a00004 mov r0, #4 ; 0x4
10001e8: eb00022d bl 1000aa4 <__builtin_new>
...
What happens if I set a breakpoint at 10001e4 is r3 will have a value of
0x3fc0008 which is 0x3ff5008 - 0x35000 but if I set a breakpoint at 10001d4
and step through until 10001e4, r3 will have 0x3ff5008. Then I hit go the
program would run okay. Somehow address 10001dc gets ignored, any ideas.
BTW, our target is a Samsung ARM7TDMI (S3C4530A). Thanks.
John Gonzaga
jgonzaga@pnicorp.com