Re-wrote interrupt handling. Now, flush_idt only initializes IDT entries

32-255. A separate routine in the new file traps.s initializes the first
32 entries with addresses pointing to exception handlers within said
file.

Modified the register_isr function to now accept a descriptor privilege
level which it will assign to the modified IDT entry.

Added a task state segment and corresponding entry to the GDT. The TSS
will store the kernel's stack pointer and stack segment when switching
to userspace. NOTE: The stack pointer MUST be saved manually before
switching to userspace!

Added the framework for a system call interface at interrupt vector 0x80
(128).

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/syscall.c b/kernel/syscall.c
new file mode 100644
index 0000000..8fa5da0
--- /dev/null
+++ b/kernel/syscall.c
@@ -0,0 +1,12 @@
+#include <kernel/con.h>
+#include <stdarg.h>
+#include <stdint.h>
+
+/* main syscall handler */
+void syscall(va_list ap) {
+  uint8_t call;
+  char *s;
+  
+  printf("Call Number: 0x%02x\n", va_arg(ap, uint8_t));
+  printf(va_arg(ap, char*));
+}