/**
@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);
}
void sysBpHandler(){
int cause;
int mode;
//1-dovremmo salvare lo stato del registro
//2-boh -> il tipo dice per evitare loop syscall :/
currentProcess->p_s.cpsr += //qualcosa;
//3-prendiamo il mode
mode= ((sysBp_old->cpsr & STATUS_SYS_MODE) >> 0x3); //forse funziona -> STATUS_SYS_MODE in uarmConst.h
//4-cause interrupt
cause=getCAUSE();
if(cause == EXC_SYSCALL){ //caso system call
//controlla se è in user mode
if(mode==TRUE){ //è definito da qualche parte il true?
//controllo se è una delle 11 syscall
if((sysBp_old->reg_a0 >= 1) && (sysBp_old->reg_a0 <= SYSCALL_MAX)){ //SYSCALL_MAX sta in const.h
sysBp_old->CP15_Cause = setCAUSE(); //siamo sicuri non ci vadano parametri?
//salva il sysbp old in pgmtrap old
pgmTrapHandler();
}
else{
//ERRORE!!! FACCIAMO UN ALTRA VOLTA!!!
}
}
else{//caso kernel mode
int ret;
/* Salva i parametri delle SYSCALL */
U32 argv1 = sysBp_old->a2;
U32 argv2 = sysBp_old->a3;
U32 argv3 = sysBp_old->a4;
/* Gestisce ogni singola SYSCALL */
switch(sysBp_old->a1)
{
case CREATEPROCESS:
//currentProcess->p_state.reg_v0 = createProcess((state_t *) arg1);
break;
case TERMINATEPROCESS:
//ris = terminateProcess((int) arg1);
//if(currentProcess != NULL) currentProcess->p_state.reg_v0 = ris;
break;
case SEMOP:
semaphoreOperation((int *) argv1, (int) argv2);
break;
case SPECSYSHDL:
break;
case SPECTLBHDL:
break;
case SPECPGMTHDL:
break;
case EXITTRAP:
break;
case GETCPUTIME:
//currentProcess->p_state.reg_v0 = getCPUTime();
break;
case WAITCLOCK:
//waitClock();
break;
case IODEVOP:
break;
case GETPID:
currentProcess->p_state.reg_v0 = getPid();
break;
/*
case WAITIO:
currentProcess->p_state.reg_v0 = waitIO((int) arg1, (int) arg2, (int) arg3);
break;
case GETPPID:
currentProcess->p_state.reg_v0 = getPpid();
break;
case SPECTLBVECT:
specTLBvect((state_t *) arg1, (state_t *)arg2);
break;
case SPECPGMVECT:
specPGMvect((state_t *) arg1, (state_t *)arg2);
break;
case SPECSYSVECT:
specSYSvect((state_t *) arg1, (state_t *)arg2);
break;
*/
default:
/* Se non è già stata eseguita la SYS12, viene terminato il processo corrente */
if(currentProcess->ExStVec[ESV_SYSBP] == 0)
{
int ris;
ris = terminateProcess(-1);
if(currentProcess != NULL) currentProcess->p_state.reg_v0 = ris;
}
/* Altrimenti viene salvata la SysBP Old Area all'interno del processo corrente */
else
{
saveCurrentState(sysBp_old, currentProcess->sysbpState_old);
LDST(currentProcess->sysbpState_new);
}
}
scheduler();
}
}
else{ //caso breakpoint
}
}