>> static union {
>> unsigned int *a; // One 32 bits address
>> unsigned long l; // One 32 bits long
>> unsigned int w[2]; // Two 16 bits words
>> unsigned char b[4]; // Four 8 bits bytes
>> } DMAaddr;
>>
>> ...
>> static void setadr( unsigned int far *buff, unsigned int length )
>> {
>> unsigned int lw;
>>
>> lw = FP_SEG( buff ); // Segment address of buffer
>> DMAaddr.w[1] = ( lw >> 12 ) & 0xf; // Makes real 32bit address
>> DMAaddr.w[0] = ( lw << 4 ) & 0xfff0;
>> DMAaddr.l += ( unsigned long )FP_OFF( buff );
>> DMAcntr.w = length;
>> }
>>
Right so I'd suspect that, as you say, you can drop the 'far' qualifier and
instead of FP_SEG and FP_OFF, you could probably just write:
static void setadr( unsigned int *buf, unsigned int length )
{
DMAaddr.a = buf;
DMAcntr.w = length;
}
Hmm .. further thoughts ... physical/ virtual addresses. What address space does
this function run in? If you're doing stuff with DMA, you need to make sure
you're using a physical address (and one that's not going to be swapped out).
Comments?
Matt
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