/****************** syscall handler in C ***************************/
int kcinth()
{
int a,b,c,d, r;
//==> WRITE CODE TO GET get syscall parameters a,b,c,d from ustack
a = get_word(running->uss, running->usp + 18); // was 26
b = get_word(running->uss, running->usp + 20); // was 28
c = get_word(running->uss, running->usp + 22); // was 30
d = get_word(running->uss, running->usp + 24); // was 32
switch(a)
{
case 0 : r = kgetpid(); break;
case 1 : r = kpd(); break;
case 2 : r = kchname(b); break;
case 3 : r = kkfork(); break;
case 4 : r = ktswitch(); break;
case 5 : r = kkwait(b); break;
case 6 : r = kkexit(b); break;
case 12: r = getMyname(b); break;
case 20: r = hop(b); break;
case 90: r = getc(); break;
case 91: r = putc(b); break;
case 99: kkexit(b); break;
default: printf("invalid syscall # : %d\n", a);
}
//==> WRITE CODE to let r be the return value to Umode
put_word(r, running->uss, running->usp + 8); // was 16
return r;
}
int kcinth()
{
u16 segment, offset;
int a,b,c,d, r;
segment = running->uss;
offset = running->usp;
//==> WRITE CODE TO GET get syscall parameters a,b,c,d from ustack
a = get_word(segment, offset + 2*PA);
b = get_word(segment, offset + 2*PB);
c = get_word(segment, offset + 2*PC);
d = get_word(segment, offset + 2*PD);
switch(a){
case 0 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kgetpid(); break;
case 1 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kps(); break;
case 2 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kchname(b); break;
case 3 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kkfork(); break;
case 4 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = ktswitch(); break;
case 5 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kkwait(b); break;
case 6 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kkexit(b); break;
case 7 : printf("hello in kernel a: %d cmd: %s\n", a, cmds[a]);r = kexec(b); break;
case 99: kkexit(b); break;
default: printf("invalid syscall # : %d\n", a);
}
put_word(r, segment, offset + 2*AX);
return r;//this will be overwritten by the pop ax register when restoring back to uMode
}
int kcinth() {
u16 segment, offset;
int a,b,c,d,r;
segment = running->uss;
offset = running->usp;
a = get_word(segment, offset + 2*PA);
b = get_word(segment, offset + 2*(PA+1));
c = get_word(segment, offset + 2*(PA+2));
d = get_word(segment, offset + 2*(PA+3));
switch(a) {
case 0:
r = getpid();
break;
case 1:
r = kps();
break;
case 2:
k = kchname();
break;
case 3:
r = kkfork();
break;
case 4:
r = kswitch();
break;
case 5:
r = kwait(b);
break;
case 6:
kexit();
break;
default:
printf("invalid syscall %d\n", a);
}
put_word(r, segment, offset + 2*AX);
}