Handout

kernel/syscall/handler.cc

@@ -0,0 +1,56 @@
+#include "syscall/handler.h"
+
+#include "arch/core.h"
+#include "arch/core_interrupt.h"
+#include "arch/gdt.h"
+#include "arch/idt.h"
+#include "debug/kernelpanic.h"
+#include "debug/output.h"
+#include "interrupt/guard.h"
+#include "syscall/skeleton.h"
+#include "syscall/stub.h"
+#include "types.h"
+
+/*! \brief Interrupt based system call entry function
+ *
+ * Low-level function written in assembly (located in `syscall/handler.asm`),
+ * calls \ref syscall_handler
+ */
+extern "C" [[gnu::interrupt]] void syscall_entry(InterruptContext *context);
+
+namespace Syscall {
+/*! \brief High level system call handler
+ * called by both low level handler in `syscall/handler.asm`.
+ *
+ * Processes the request by delegating it to the appropriate function identified
+ * by the system call number -- allowing up to five parameters for the system
+ * call.
+ *
+ * \param p1 first parameter
+ * \param p2 second parameter
+ * \param p3 third parameter
+ * \param p4 fourth parameter
+ * \param p5 fifth parameter
+ * \param sysnum identifier for the system call
+ * \param user pointer to the interrupt \ref context (for example to determine
+ * instruction pointer)
+ * \return system call return value
+ */
+extern "C" size_t syscall_handler(size_t sysnum, size_t p1, size_t p2,
+								  size_t p3, size_t p4, size_t p5,
+								  InterruptContext *user) {
+	(void)p1;
+	(void)p2;
+	(void)p3;
+	(void)p4;
+	(void)p5;
+	(void)sysnum;
+	(void)user;
+	return static_cast<size_t>(-1);
+}
+
+void init() {
+	// Set interrupt based syscall handler
+}
+
+}  // namespace Syscall