did some restructuring, got multitasking almost working

kernel/drivers/pic/pic.S

@@ -0,0 +1,70 @@
+#define PIC1_ADDR	0x20 + 0xC0000000
+#define PIC2_ADDR	0xA0 + 0xC0000000		
+#define PIC1_COMMAND	PIC1_ADDR
+#define PIC1_DATA	(PIC1_ADDR+1)
+#define PIC2_COMMAND	PIC2_ADDR
+#define PIC2_DATA	(PIC2_ADDR+1)
+#define PIC_EOI		0x20
+
+.code32
+
+.global init_pic
+init_pic:
+    # init command
+    mov $0x11, %al
+    outb %al, $PIC1_COMMAND
+    outb %al, $PIC2_COMMAND
+
+    # vector offsets
+    mov $0x20, %al
+    outb %al, $PIC1_DATA
+    mov $0x28, %al
+    outb %al, $PIC2_DATA
+
+    # cascade 
+    mov $0x04, %al
+    outb %al, $PIC1_DATA
+    mov $0x02, %al  
+    outb %al, $PIC2_DATA 
+
+    # env
+    mov $0x01, %al
+    outb %al, $PIC1_DATA
+    outb %al, $PIC2_DATA 
+
+    # mask
+    mov $0xF8, %al
+    outb %al, $PIC1_DATA
+    mov $0x3F, %al
+    outb %al, $PIC2_DATA 
+
+    ret
+
+.global send_eoi_master
+send_eoi_master:
+    mov $0x20, %al
+    outb %al, $PIC1_COMMAND
+    ret 
+
+.global send_eoi_slave 
+send_eoi_slave:
+    mov $0x20, %al
+    outb %al, $PIC2_COMMAND
+    call send_eoi_master
+    ret 
+
+.global read_isr_master
+read_isr_master:
+    xorl %eax, %eax
+    mov $0x0B, %al
+    outb %al, $PIC1_COMMAND
+    in $PIC1_COMMAND, %al
+    ret
+
+.global read_isr_slave 
+read_isr_slave:
+    xorl %eax, %eax
+    mov $0x0B, %al
+    outb %al, $PIC2_COMMAND
+    in $PIC2_COMMAND, %al
+    ret