DMA and Uart

for example i have to send this structure data do uart

typedef struct RS485{

float data1;

float data2;

int data3[10];

long data4;

}mydata;

with sizeof(mydata) i can know the lenght of datas to send

but there is not addressof(...) function to know the address in memory

of my data structure ;

The function alt_dma_txchan receive differents arguments , i can

put &mydata instead the address in memory , i will try

but where i specifie the uart ?

thanks

walter

ciao