STM32MP257 OpenAMP RPMsg – Endpoint not getting created
Hi,
I’m working on STM32MP257F-DK (A35 + M33) using OpenAMP + RPMsg over IPCC and facing an issue with RPMsg endpoint creation on the M33 side.
Goal
Simple use case:
Linux (A35) sends "START" / "STOP"
M33 receives the message via RPMsg
M33 toggles an LED
What is working
M33 firmware builds and boots correctly using remoteproc
Resource table is detected
Virtio RPMsg is created on Linux
From Linux dmesg:
virtio_rpmsg_bus virtio0: rpmsg host is online
remoteproc remoteproc0: remote processor m33 is now upSo remoteproc and OpenAMP transport are working.
Problem
With the following M33 code, RPMsg endpoint is not getting created on Linux side:
int rpmsg_recv_callback(struct rpmsg_endpoint *ept,
void *data,
size_t len,
uint32_t src,
void *priv)
{
if (len >= 5 && strncmp((char *)data, "START", 5) == 0)
{
led_run = 1;
}
else if (len >= 4 && strncmp((char *)data, "STOP", 4) == 0)
{
led_run = 0;
HAL_GPIO_WritePin(GPIOZ, GPIO_PIN_0, GPIO_PIN_RESET);
}
return 0;
}
struct rpmsg_device *rpmsg_dev;
// extern struct rpmsg_device *rpmsg_dev;
void OPENAMP_CreateEndpoint(void)
{
// if (!rpmsg_dev)
// {
// /* OpenAMP not ready yet */
// loc_printf("OpenAMP not ready yet.\r\n");
// return;
// }
int status;
status = rpmsg_create_ept(&rp_endpoint,
rpmsg_dev,
"rpmsg-led",
RPMSG_ADDR_ANY,
RPMSG_ADDR_ANY,
rpmsg_recv_callback,
NULL);
if(status < 0){
printf("End Point not created.\r\n");
while(1){
HAL_GPIO_TogglePin(GPIOZ, GPIO_PIN_0);
HAL_Delay(100);
}
}
}
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* IPCC initialisation */
MX_IPCC1_Init();
if(!IS_DEVELOPER_BOOT_MODE())
{
/*Corpo Sync Initialization*/
CoproSync_Init();
}
/* OpenAmp initialisation ---------------------------------*/
MX_OPENAMP_Init(RPMSG_REMOTE, NULL);
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
/* USER CODE BEGIN 2 */
OPENAMP_CreateEndpoint();
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
OPENAMP_check_for_message();
if (led_run)
{
HAL_GPIO_TogglePin(GPIOZ, GPIO_PIN_0);
HAL_Delay(500);
}
else
{
HAL_Delay(10);
}
}
/* USER CODE END 3 */
}But:
rpmsg_create_ept() returns -1Because of this:
Endpoint is not created on M33
Linux never sees or binds to the endpoint
No userspace RPMsg channel is available
M33 callback is never triggered
Linux side observation
/sys/class/rpmsg → only rpmsg_ctrl0
/dev → rpmsg0, rpmsg_ctrl0
No RPMsg data endpoint appears
/sys/class/rpmsg/rpmsg_ctrl0/new_endpoint → permission denied
/dev/ttyRPMSG* does not exist
Any guidance or reference example for STM32MP257 RPMsg endpoint creation on M33 would be very helpful.
Thanks.