C++ (Cpp) CAUSE_EXCCODE_SET Examples

Example #1

File: exceptions.c Project: OS-StudentGroup/OS-Project

/**
@brief This function handles a system call request coming from a process running in User Mode.
@return Void.
*/
HIDDEN void syscallUserMode()
{
	/* [Case 1] A privileged system call has been raised */
	if (SYSBP_Old->a1 > 0 && SYSBP_Old->a1 < 9)
	{
		/* Save SYS/BP Old Area into PgmTrap Old Area */
		saveCurrentState(SYSBP_Old, PGMTRAP_Old);

		/* Set program trap cause to RI (Reserved Instruction) */
		PGMTRAP_Old->CP15_Cause = CAUSE_EXCCODE_SET(PGMTRAP_Old->CP15_Cause, EXC_RESERVEDINSTR);

		/* Call the trap handler in order to trigger the PgmTrap exception response */
		pgmTrapHandler();
	}
	/* [Case 2] A non privileged system call has been raised */
	else
		/* Distinguish whether SYS5 has been invoked or not */
		checkSYS5(SYSBK_EXCEPTION, SYSBP_Old);
}

Example #2

File: exceptions.c Project: illbexyz/kaya-os-uarm

void sysBpHandler(){
	saveStateIn(sysbp_old, &currentProcess->p_s);
	unsigned int cause = CAUSE_EXCCODE_GET(sysbp_old->CP15_Cause);
	unsigned int a0 = (*sysbp_old).a1;
	unsigned int a1 = (*sysbp_old).a2;
	unsigned int a2 = (*sysbp_old).a3;
	unsigned int a3 = (*sysbp_old).a4;
	/* Se l'eccezione è di tipo System call */
	if(cause==EXC_SYSCALL){
    	/* Se il processo è in kernel mode gestisce adeguatamente */
    	if( (currentProcess->p_s.cpsr & STATUS_SYS_MODE) == STATUS_SYS_MODE){
			/* Se è fra SYS1 e SYS8 richiama le funzioni adeguate */
			switch(a0){
			    case CREATEPROCESS:
			        createProcess((state_t *) a1);
			        break;
			    case TERMINATEPROCESS:
			        terminateProcess(currentProcess);
			        break;
		        case VERHOGEN:
		            verhogen((int *) a1);
			        break;
		        case PASSEREN:
		            passeren((int *) a1);
			        break;
		        case SPECTRAPVEC:
		            specExStVec((int) a1, (state_t *) a2, (state_t *) a3);
			        break;
		        case GETCPUTIME:
		            getCPUTime();
			        break;
		        case WAITCLOCK:
		            waitForClock();
			        break;
		        case WAITIO:
		            waitForIO((int) a1, (int) a2, (int) a3);
			        break;
			    /* Altrimenti la gestione viene passata in alto */
			    default:
			        useExStVec(SPECSYSBP);
				break;            
			}
			
		    /* Richiamo lo scheduler */
		    scheduler();
		/* Se invece è in user mode */
		} else if((currentProcess->p_s.cpsr & STATUS_USER_MODE) == STATUS_USER_MODE){
			/* Se è una system call */
			if(a0 >= CREATEPROCESS && a0 <= WAITIO){
			    /* Gestisco come fosse una program trap */
			    saveStateIn(sysbp_old, pgmtrap_old);
			    /* Setto il registro cause a Reserved Instruction */
			    pgmtrap_old->CP15_Cause = CAUSE_EXCCODE_SET(pgmtrap_old->CP15_Cause, EXC_RESERVEDINSTR);
			    /* Richiamo l'handler per le pgmtrap */
			    pgmHandler();
			} else {
				useExStVec(SPECSYSBP);
			}
		}
	/* Altrimenti se l'eccezione è di tipo BreakPoint */
	} else if(cause == EXC_BREAKPOINT){
		useExStVec(SPECSYSBP);
	}

	PANIC();
}