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
}
/************** syscall routing table ***********/
int kcinth()
{
u16 x, y, z, w, r;
u16 seg, off;
seg = running->uss; off = running->usp;
x = get_word(seg, off+13*2);
y = get_word(seg, off+14*2);
z = get_word(seg, off+15*2);
w = get_word(seg, off+16*2);
switch(x){
case 0 : r = running->pid; break;
case 1 : r = kps(); break;
case 2 : r = chname(y); break;
case 3 : r = kmode(); break;
case 4 : r = tswitch(); break;
case 5 : r = kwait(); break;
case 6 : r = kexit(); break;
case 7 : r = fork(); break;
case 8 : r = kexec(y); break;
case 9 : r = sout(y); break;
case 10: r = sin(y); break;
case 99: r = kexit(); break;
default: printf("invalid syscall # : %d\n", x);
}
put_word(r, seg, off+2*8);
}
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);
}
int body() {
char c;
printf("proc %d resumes to body()\n", running->pid);
while(1) {
printLists();
printf("proc %d[%d] running: parent=%d\n",
running->pid, running->priority, running->ppid);
printf("enter a char [Debug|Fork|Umode|Ps|Quit|Sleep|Wait] : ");
c = getc(); printf("%c\n", c);
switch(c) {
case 's' : tswitch(); break;
case 'f' : kfork(); break;
case 'q' : kexit(); break;
case 'p' : kps(); break;
case 'w' : kwait(); break;
case 'd' : debugStatement(); break;
case 'u' : goUmode(); break;
}
}
}
/****************** 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 + 26);
b = get_word(running->uss, running->usp + 28);
c = get_word(running->uss, running->usp + 30);
d = get_word(running->uss, running->usp + 32);
switch(a){
case 0 : r = kgetpid(); break;
case 1 : r = kps(); break;
case 2 : r = kchname(b); break;
case 3 : r = kmode(); break;
case 4 : r = tswitch(); break;
case 5 : r = kkwait(b); break;
case 6 : r = kkexit(b); break;
case 7 : r = fork(); break;
case 8 : r = kexec(b); break;
case 30: r = kpipe(b); break;
case 31: r = read_pipe(b,c,d); break;
case 32: r = write_pipe(b,c,d);break;
case 33: r = close_pipe(b); break;
case 34: r = pfd(); 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 + 16);
return r;
}
void debugStatement() {
int flag = 1;
char c;
while (flag) {
printf("Debug Point (l, n, p, num): ");
c = getc();
printf("\n");
switch(c) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
printProc(&proc[c-'0']);
break;
case 'n':
printf("nproc: %d\n", nproc);
break;
case 'p':
kps();
break;
case 'l':
printLists();
break;
default:
flag = 0;
break;
}
}
}
int kbhandler()
{
int scode, value, c;
KBD *kp = &kbd;
scode = in_byte(KEYBD); // get scan code
value = in_byte(PORT_B); // strobe PORT_B to ack the char
out_byte(PORT_B, value | KBIT);
out_byte(PORT_B, value);
if (scode & 0x80)
{// key release: ONLY catch shift
scode &= 0x7F; // mask out bit 7
if (scode == LSHIFT || scode == RSHIFT)
shifted = 0; // released the shift key
goto out;
}
// from here on, must be key press
if (scode == 1) // Esc key on keyboard
goto out;
if (scode == LSHIFT || scode == RSHIFT)
{
shifted = 1; // set shifted flag
goto out;
}
if (scode == 0x3A)
{
capslock++; // capslock key acts like a toggle
capslock %= 2;
goto out;
}
/************* Catch and handle F keys for debugging *************/
if (scode == F1)
{
kps();
goto out;
}
if (scode == F2)
{
printList("readyQueue", readyQueue);
goto out;
}
if (scode == F3)
{
printList("freelist", freeList);
goto out;
}
if( scode == F4)
{
printSleep();
goto out;
}
if (scode == F12)
{
kexit(F12);
goto out;
}
// translate scan code to ASCII, using shift[ ] table if shifted;
if(shifted)
c = shift[scode];
else
c = unshift[scode];
// Convert all to upper case if capslock is on
if (capslock){
if (c >= 'A' && c <= 'Z')
c += 'a' - 'A';
else if (c >= 'a' && c <= 'z')
c -= 'a' - 'A';
}
/* enter the char in kbd.buf[ ] for process to get */
if (kbd.data.value == KBLEN)
{
printf("%c\n", BELL);
goto out; // kb.buf[] already FULL
}
kbd.buf[kbd.head++] = c;
kbd.head %= KBLEN;
V(&kbd.data);
out:
out_byte(0x20, 0x20);
}
