u8    otp_phy_ver:2;
 } __packed;
 
-#define API_OPN_SIZE                                    14
-#define API_UID_SIZE                                    8
-#define API_DISABLED_CHANNEL_LIST_SIZE                  2
-#define API_FIRMWARE_LABEL_SIZE                         128
-
 struct hif_ind_startup {
        u32   status;
        u16   hardware_id;
-       u8    opn[API_OPN_SIZE];
-       u8    uid[API_UID_SIZE];
+       u8    opn[14];
+       u8    uid[8];
        u16   num_inp_ch_bufs;
        u16   size_inp_ch_buf;
        u8    num_links_ap;
        u8    firmware_minor;
        u8    firmware_major;
        u8    firmware_type;
-       u8    disabled_channel_list[API_DISABLED_CHANNEL_LIST_SIZE];
+       u8    disabled_channel_list[2];
        struct hif_otp_regul_sel_mode_info regul_sel_mode_info;
        struct hif_otp_phy_info otp_phy_info;
        u32   supported_rate_mask;
-       u8    firmware_label[API_FIRMWARE_LABEL_SIZE];
+       u8    firmware_label[128];
 } __packed;
 
 struct hif_ind_wakeup {
 } __packed;
 
 
-#define HIF_EXCEPTION_DATA_SIZE            124
-
 struct hif_ind_exception {
-       u8    data[HIF_EXCEPTION_DATA_SIZE];
+       u8    data[124];
 } __packed;
 
 
        u32   status;
 } __packed;
 
-#define API_HOST_PUB_KEY_SIZE                           32
-#define API_HOST_PUB_KEY_MAC_SIZE                       64
-
 enum hif_sl_session_key_alg {
        HIF_SL_CURVE25519                                = 0x01,
        HIF_SL_KDF                                       = 0x02
 };
 
+#define API_HOST_PUB_KEY_SIZE                           32
+#define API_HOST_PUB_KEY_MAC_SIZE                       64
+
 struct hif_req_sl_exchange_pub_keys {
        u8    algorithm:2;
        u8    reserved1:6;
        u8    ncp_pub_key_mac[API_NCP_PUB_KEY_MAC_SIZE];
 } __packed;
 
-#define API_ENCR_BMP_SIZE        32
-
 struct hif_req_sl_configure {
-       u8    encr_bmp[API_ENCR_BMP_SIZE];
+       u8    encr_bmp[32];
        u8    disable_session_key_protection:1;
        u8    reserved1:7;
        u8    reserved2[3];
 
        u8    reserved4[3];
 } __packed;
 
-#define HIF_API_OUI_SIZE                                3
-#define HIF_API_MATCH_DATA_SIZE                         3
-
 struct hif_ie_table_entry {
        u8    ie_id;
        u8    has_changed:1;
        u8    has_appeared:1;
        u8    reserved:1;
        u8    num_match_data:4;
-       u8    oui[HIF_API_OUI_SIZE];
-       u8    match_data[HIF_API_MATCH_DATA_SIZE];
+       u8    oui[3];
+       u8    match_data[3];
 } __packed;
 
 struct hif_mib_bcn_filter_table {
        HIF_TMPLT_NA                               = 0x7
 };
 
-#define HIF_API_MAX_TEMPLATE_FRAME_SIZE                              700
-
 struct hif_mib_template_frame {
        u8    frame_type;
        u8    init_rate:7;
        u8    mode:1;
        u16   frame_length;
-       u8    frame[HIF_API_MAX_TEMPLATE_FRAME_SIZE];
+       u8    frame[700];
 } __packed;
 
 struct hif_mib_beacon_wake_up_period {