idt: Move dummy_isr() to its own assembly file

stage23/sys/dummy_isr.asm

@@ -0,0 +1,8 @@
+extern lapic_eoi
+
+global dummy_isr
+dummy_isr:
+    pusha
+    call lapic_eoi
+    popa
+    iretd

stage23/sys/dummy_isr.asm32

@@ -0,0 +1 @@
+dummy_isr.asm

stage23/sys/dummy_isr.asm64

@@ -0,0 +1,24 @@
+extern lapic_eoi
+
+global dummy_isr
+dummy_isr:
+    push rax
+    push rcx
+    push rdx
+    push rsi
+    push rdi
+    push r8
+    push r9
+    push r10
+    push r11
+    call lapic_eoi
+    pop r11
+    pop r10
+    pop r9
+    pop r8
+    pop rdi
+    pop rsi
+    pop rdx
+    pop rcx
+    pop rax
+    iretq

stage23/sys/idt.c

@@ -9,11 +9,7 @@
 
 static struct idt_entry *dummy_idt = NULL;
 
-__attribute__((interrupt))
-static void dummy_isr(void *p) {
-    (void)p;
-    lapic_eoi();
-}
+void dummy_isr(void);
 
 void init_flush_irqs(void) {
     size_t dummy_idt_size = 256 * sizeof(struct idt_entry);