1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
#include <kernel/arch/generic.h>
#include <kernel/panic.h>
#include <kernel/proc.h>
#include <kernel/syscalls.h>
#include <stdint.h>
_Noreturn void _syscall_exit(const char *msg, size_t len) {
process_current->state = PS_DEAD;
process_current = process_find(PS_RUNNING);
if (process_current)
process_switch(process_current);
tty_const("last process returned. ");
panic();
}
int _syscall_fork() {
struct process *orig = process_current;
process_current = process_clone(orig);
process_switch(process_current);
}
int _syscall_debuglog(const char *msg, size_t len) {
struct pagedir *pages = process_current->pages;
size_t remaining = len;
while (remaining > 0) {
/* note: While i'm pretty sure that this should always work, this
* was only tested in cases where the pages were consecutive both in
* virtual and physical memory, which might not always be the case.
* TODO test this */
void *phys = pagedir_virt2phys(pages, msg, true, false);
size_t partial = remaining;
// don't read past the page
if (((uintptr_t)msg & PAGE_MASK) + remaining > PAGE_SIZE)
partial = PAGE_SIZE - ((uintptr_t)msg & PAGE_MASK);
tty_write(phys, partial);
remaining -= partial;
msg += partial;
}
return len;
}
int syscall_handler(int num, int a, int b, int c) {
switch (num) {
case _SYSCALL_EXIT:
_syscall_exit((void*)a, b);
case _SYSCALL_FORK:
return _syscall_fork();
case _SYSCALL_DEBUGLOG:
return _syscall_debuglog((void*)a, b);
default:
tty_const("unknown syscall ");
panic();
}
}
|
