add a barebones exit() syscall

2 files changed, 12 insertions, 0 deletions

diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index 24706d3..1bc1a44 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -4,6 +4,13 @@
 #include <kernel/syscalls.h>
 #include <stdint.h>
 
+int sc_exit(const char *msg, size_t len) {
+	// the message is currently ignored
+	
+	log_const("last process returned. ");
+	panic();
+}
+
 int sc_debuglog(const char *msg, size_t len) {
 	struct pagedir *pages = process_current->pages;
 	void *phys = pagedir_virt2phys(pages, msg, true, false);
@@ -23,6 +30,9 @@ int syscall_handler(int num, int a, int b, int c, void *stack, void *eip) {
 	process_current->eip = eip;
 
 	switch (num) {
+		case SC_EXIT:
+			sc_exit((void*)a, b);
+			panic(); // sc_exit should never return
 		case SC_DEBUGLOG:
 			return sc_debuglog((void*)a, b);
 		default:
diff --git a/src/kernel/syscalls.h b/src/kernel/syscalls.h
index 39db6a9..a249046 100644
--- a/src/kernel/syscalls.h
+++ b/src/kernel/syscalls.h
@@ -2,5 +2,7 @@
 
 // not caring about stable syscall numbers just yet
 enum {
+	SC_EXIT,
+	
 	SC_DEBUGLOG
 };