barebones `memflag()` implementation - letting the user allocate pages

2 files changed, 10 insertions, 0 deletions

diff --git a/src/init/main.c b/src/init/main.c
index 06e59a2..dc5a975 100644
--- a/src/init/main.c
+++ b/src/init/main.c
@@ -1,4 +1,5 @@
 #include <init/types.h>
+#include <shared/flags.h>
 #include <shared/syscalls.h>
 #include <stdint.h>
 
@@ -8,6 +9,8 @@
 __attribute__((section("text")))
 int tty_fd;
 
+int test;
+
 void fs_test(void);
 
 int main(void) {
@@ -16,6 +19,9 @@ int main(void) {
 		_syscall_exit(argify("couldn't open tty"));
 	log(" opened /tty ");
 
+	_syscall_memflag(&test, sizeof(int), MEMFLAG_PRESENT);
+	test = 0; // would cause a pagefault without the memflag call
+
 	fs_test();
 	_syscall_exit(argify("my job here is done."));
 }
diff --git a/src/init/syscalls.c b/src/init/syscalls.c
index e63f911..8d5ecf2 100644
--- a/src/init/syscalls.c
+++ b/src/init/syscalls.c
@@ -44,3 +44,7 @@ handle_t _syscall_fs_create(handle_t __user *back) {
 int _syscall_fs_wait(handle_t back, char __user *buf, int __user *len) {
 	return _syscall(_SYSCALL_FS_WAIT, back, (int)buf, (int)len);
 }
+
+int _syscall_memflag(void __user *addr, size_t len, int flags) {
+	return _syscall(_SYSCALL_MEMFLAG, (int)addr, len, flags);
+}