intr_get_level (void)
{
uint32_t flags;
-
+
+ /* Push the flags register on the processor stack, then pop the
+ value off the stack into `flags'. See [IA32-v2b] "PUSHF"
+ and "POP" and [IA32-v3] 5.8.1. */
asm volatile ("pushfl; popl %0" : "=g" (flags));
return flags & FLAG_IF ? INTR_ON : INTR_OFF;
{
enum intr_level old_level = intr_get_level ();
ASSERT (!intr_context ());
+
+ /* Enable interrupts by setting the interrupt flag.
+ See [IA32-v2b] "STI" and [IA32-v3] 5.8.1. */
asm volatile ("sti");
+
return old_level;
}
intr_disable (void)
{
enum intr_level old_level = intr_get_level ();
+
+ /* Disable interrupts by clearing the interrupt flag.
+ See [IA32-v2b] "CLI" and [IA32-v3] 5.8.1. */
asm volatile ("cli");
+
return old_level;
}
\f
for (i = 0; i < INTR_CNT; i++)
idt[i] = make_intr_gate (intr_stubs[i], 0);
- /* Load IDT register. */
+ /* Load IDT register.
+ See [IA32-v2a] "LIDT" and [IA32-v3] 5.10. */
idtr_operand = make_idtr_operand (sizeof idt - 1, idt);
asm volatile ("lidt %0" :: "m" (idtr_operand));
intr_names[11] = "#NP Segment Not Present";
intr_names[12] = "#SS Stack Fault Exception";
intr_names[13] = "#GP General Protection Exception";
+ intr_names[14] = "#PF Page-Fault Exception";
intr_names[16] = "#MF x87 FPU Floating-Point Error";
intr_names[17] = "#AC Alignment Check Exception";
intr_names[18] = "#MC Machine-Check Exception";
void
intr_dump_frame (const struct intr_frame *f)
{
- uint32_t cr2, ss;
+ uint32_t cr2;
+
+ /* Store current value of CR2 into `cr2'.
+ CR2 is the linear address of the last page fault.
+ See [IA32-v2a] "MOV--Move to/from Control Registers" and
+ [IA32-v3] 5.14 "Interrupt 14--Page Fault Exception
+ (#PF)". */
asm ("movl %%cr2, %0" : "=r" (cr2));
- asm ("movl %%ss, %0" : "=r" (ss));
printf ("Interrupt %#04x (%s) at eip=%p\n",
f->vec_no, intr_names[f->vec_no], f->eip);
printf (" esi=%08"PRIx32" edi=%08"PRIx32" esp=%08"PRIx32" ebp=%08"PRIx32"\n",
f->esi, f->edi, (uint32_t) f->esp, f->ebp);
printf (" cs=%04"PRIx16" ds=%04"PRIx16" es=%04"PRIx16" ss=%04"PRIx16"\n",
- f->cs, f->ds, f->es, f->cs != SEL_KCSEG ? f->ss : ss);
+ f->cs, f->ds, f->es, f->ss);
}
/* Returns the name of interrupt VEC. */