Fix compiler warnings

1 files changed, 13 insertions, 5 deletions

diff --git a/devices/pic_8259.c b/devices/pic_8259.c
index 7b4807c..75aaf6d 100644
--- a/devices/pic_8259.c
+++ b/devices/pic_8259.c
@@ -33,17 +33,25 @@ pic_init()
   outb(0xff, PIC2 + DATA);
 }
 
+static unsigned char
+irq_mask(unsigned char irq)
+{
+  unsigned char mask = (unsigned char)~(1u << irq);
+  return 0xff & mask;
+}
+
 void
 pic_enable()
 {
   unsigned char mask1 = 0xff;
-  mask1 &= ~(1 << 0); /* irq0 timer */
-  mask1 &= ~(1 << 1); /* irq1 keyboard */
-  mask1 &= ~(1 << 2); /* irq1 cascade */
+  unsigned char mask2 = 0xff;
+
+  mask1 &= irq_mask(0); /* irq0 timer */
+  mask1 &= irq_mask(1); /* irq1 keyboard */
+  mask1 &= irq_mask(2); /* irq2 cascade */
   outb(mask1, PIC1 + DATA);
 
-  unsigned char mask2 = 0xff;
-  mask2 &= ~(1 << 4); /* irq12 mouse */
+  mask2 &= irq_mask(12 - 8); /* irq12 mouse */
   outb(mask2, PIC2 + DATA);
 
   enable_interrupts();