_sd_read
err = _sd_read(intfhdl, addr, cnt, mem);
err = _sd_read(intfhdl, addr, n, tmpbuf);
_sd_read(intfhdl, addr, 4, status);
s32 _sd_read(struct intf_hdl *pintfhdl, u32 addr, u32 cnt, void *pdata);
err = _sd_read(pintfhdl, addr, cnt, pdata);