Cdsc_handler.c
/* UDS 0x10: DiagnosticSessionControl — switches ECU diagnostic session */
/* Called via DCM callback in AUTOSAR bootloader */
#include "Dcm.h"
#include "Dcm_Cbk.h"
/* Session IDs */
#define SESSION_DEFAULT 0x01u
#define SESSION_PROGRAMMING 0x02u
#define SESSION_EXTENDED 0x03u
/* DSC response: 0x50 + subFunction + P2 (2 bytes) + P2* (2 bytes, in 10ms units) */
typedef struct {
uint8_t sid_resp; /* 0x50 */
uint8_t session_type; /* echo of requested sub-function */
uint16_t p2_ms; /* 50 ms default */
uint16_t p2star_10ms; /* 5000 ms default → 500 in units of 10 ms */
} DscResponse_t;
Std_ReturnType Dcm_DSC_Handler(const uint8_t *req, uint16_t req_len,
uint8_t *resp, uint16_t *resp_len)
{
uint8_t session = req[1]; /* sub-function byte */
switch (session) {
case SESSION_DEFAULT:
/* Always accessible from any session */
Dcm_SetActiveSession(SESSION_DEFAULT);
/* Clear security level: level 0 (no access) */
Dcm_SetSecurityLevel(0u);
break;
case SESSION_EXTENDED:
/* Extended: accessible from default or programming */
Dcm_SetActiveSession(SESSION_EXTENDED);
break;
case SESSION_PROGRAMMING:
/* Programming: only from Extended Session */
if (Dcm_GetActiveSession() != SESSION_EXTENDED) {
resp[0] = 0x7Fu; resp[1] = 0x10u; resp[2] = 0x25u; /* NRC 0x25: wrong session */
*resp_len = 3u;
return E_NOT_OK;
}
/* Set boot flag: next reset will stay in PBL reprog mode */
BootFlags_Set(REPROG_MAGIC);
Dcm_SetActiveSession(SESSION_PROGRAMMING);
break;
default:
resp[0] = 0x7Fu; resp[1] = 0x10u; resp[2] = 0x12u; /* NRC 0x12: subFunctionNotSupported */
*resp_len = 3u;
return E_NOT_OK;
}
/* Positive response */
resp[0] = 0x50u; resp[1] = session;
resp[2] = 0x00u; resp[3] = 0x32u; /* P2 = 50 ms */
resp[4] = 0x01u; resp[5] = 0xF4u; /* P2* = 500 × 10ms = 5000 ms */
*resp_len = 6u;
return E_OK;
}