Primitive ability to call kernel code from userspace.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/user/syscall.c b/src/user/syscall.c
new file mode 100644
index 0000000..3aa0707
--- /dev/null
+++ b/src/user/syscall.c
@@ -0,0 +1,17 @@
+#include "user/syscall.h"
+
+#include <stdint.h>
+
+void __attribute__ ((noinline)) do_syscall(
+    volatile uint32_t id,
+    volatile uint32_t arg)
+{
+  asm volatile("svc #0x04");
+}
+
+#define SYSCALL(id, fn, kernfn, argt) \
+  void fn(argt arg) \
+{ \
+  do_syscall(id, (uint32_t) arg); \
+}
+#include "kern/syscall/syscall_tbl.inc"