Finally fix multitasking to work on a PC

src/isr_wrapper.s

@@ -30,7 +30,14 @@ exc_wrapper_code:
 apic_timer_isr_wrap:
     ;//Disable interrupts
     cli
-    cmp byte ptr [mtask_enabled], 1
+    ;//Save RAX
+    push rax
+    ;//Check if multitasking is enabled
+    call mtask_is_enabled
+    cmp rax, 1
+    ;//Restore RAX
+    pop rax
+    ;//Return if not
     je apic_timer_isr_wrap_cont
     ;//Re-enable interrupts; send EOI; return
     push r15

src/mtask/mtask.c

@@ -12,10 +12,22 @@ uint32_t mtask_cur_task_no;
 uint8_t mtask_enabled;
 task_t* mtask_cur_task;
 
+/*
+ * Returns the current task pointer
+ * (used only by mtask_sw.s)
+ */
 task_t* mtask_get_cur_task(){
     return mtask_cur_task;
 }
 
+/*
+ * Is multitasking enabled?
+ * (used only by mtask_sw.s)
+ */
+uint64_t mtask_is_enabled(){
+    return mtask_enabled;
+}
+
 /*
  * Initializes the multitasking system
  */

src/stdlib.h

@@ -6,7 +6,7 @@
 #endif
 
 //The kernel version
-#define KRNL_VERSION_STR "v0.4.6"
+#define KRNL_VERSION_STR "v0.4.7"
 
 //Use WC for memcpy() transfers?
 #define STDLIB_MEMCPY_WC