syscall parameter & return value passing

Sadly, sysenter on i386 limits me to only 4 arguments (so, 1 for the
syscall id + 3 real args). If that turns out to be an issue I'll either
just switch to interrupts, or switch to x64.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/init/main.c b/src/init/main.c
index cb3fa1d..6c4ccc3 100644
--- a/src/init/main.c
+++ b/src/init/main.c
@@ -1,15 +1,15 @@
 #include <stdint.h>
 
-void _syscall();
+int _syscall(int, int, int, int);
 
 int main() {
-	_syscall();
+	uint8_t color = _syscall(1, 2, 3, 4);
 
 	// change the colors of VGA text
 	// doesn't require a lot of code, but still shows that it's working
 	uint8_t *vga = (void*) 0xB8000;
 	for (int i = 0; i < 80 * 25; i++)
-		vga[(i << 1) + 1] = 0x4e;
+		vga[(i << 1) + 1] = color;
 
 	// try to mess with kernel memory
 	uint8_t *kernel = (void*) 0x100000;