Whole CAN code in RIOT is using 'struct can_frame' to represent a CAN
frame.
However incoming CAN FD support will bring 'struct canfd_frame' to
represent CAN FD frames.
Even if the 'struct canfd_frame' has additional flags and a bigger
payload, it is aligned on 'struct can_frame' and thus they can be
referenced by the same pointers in the code.
As it is impossible to predict which one will be used in RIOT, just
define a new type 'can_frame_t' which will map to the right struct
according to the MCU CAN supported format.
Signed-off-by: Gilles DOFFE <gilles.doffe@rtone.fr>
RIOT implementation of CAN bus relies on SocketCAN model.
Since commit c398e56 (can: add optional DLC element to Classical CAN
frame structure), '__u8 can_dlc' attribute of struct can_frame is
considered as deprecated in SocketCAN and kept for legacy support.
Attribute '__u8 len' should be used instead.
union {
/* CAN frame payload length in byte (0 .. CAN_MAX_DLEN)
* was previously named can_dlc so we need to carry that
* name for legacy support
*/
__u8 len;
__u8 can_dlc; /* deprecated */
};
Moreover, CAN FD frame structure does not support legacy attribute
'can_dlc', making 'len' mandatory for incoming CAN FD support in RIOT.
struct canfd_frame {
canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
__u8 len; /* frame payload length in byte */
__u8 flags; /* additional flags for CAN FD */
__u8 __res0; /* reserved / padding */
__u8 __res1; /* reserved / padding */
__u8 data[CANFD_MAX_DLEN]
__attribute__((aligned(8)));
};
Signed-off-by: Gilles DOFFE <gilles.doffe@rtone.fr>
We do not need to add an array of pointers to the shell commands, just
an array of shell commands is sufficient. This reduced the overhead of
XFA by `sizeof(void *)` per command.
This command does the same as `help`, but provides a machine readable
JSON rather than a human readable table. It is only provided when the
(pseudo-)module `shell_builtin_cmd_help_json` is used.
It would seem that either we need to require the periph_pm module in shell
or make it optional... since we have many other optional modules here
and we still may want the RIOT_VERSION command, lets make it optional for now.
This allows to define an extra string that will be output as part
of the version command.
e.g. an application may define
RIOT_VERSION_EXTRA += v1.33.7
RIOT_VERSION_EXTRA += flashed by $(shell whoami
