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Altera_Forum
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15 years ago

Exception Handler for misaligned data memory access

Hi All, I'm after some help... Does anybody have available or point me in the direction of a worked example of an exception handler which processes NIOS2_EXCEPTION_MISALIGNED_DATA_ADDR excepti...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

GCC generate the code to do multiple bus cycles to access misaligned data for members of 'packed' structures and structure members with alignment constraint, however it won't let you define a 'pointer to packed int'.

The following does work (retyped): 

typedef struct { int v; } __attribute__((packed)) packed_int;
struct foo {
     char x;
     packed_int y;
};
int bar(foo *z)
{
    packed_int *p = &z->y;
    return p->v;
}