+ return eax;
+}
+
+// 16bit trampoline for enabling irqs from 32bit mode.
+ASM16(
+ " .global trampoline_checkirqs\n"
+ "trampoline_checkirqs:\n"
+ " rep ; nop\n"
+ " lretw"
+ );
+
+static void
+check_irqs(void)
+{
+ if (MODESEGMENT) {
+ asm volatile(
+ "sti\n"
+ "nop\n"
+ "rep ; nop\n"
+ "cli\n"
+ "cld\n"
+ : : :"memory");
+ return;
+ }
+ extern void trampoline_checkirqs();
+ struct bregs br;
+ br.flags = F_IF;
+ br.code.seg = SEG_BIOS;
+ br.code.offset = (u32)&trampoline_checkirqs;
+ call16big(&br);
+}
+
+// 16bit trampoline for waiting for an irq from 32bit mode.
+ASM16(
+ " .global trampoline_waitirq\n"
+ "trampoline_waitirq:\n"
+ " sti\n"
+ " hlt\n"
+ " lretw"
+ );
+
+// Wait for next irq to occur.
+void
+wait_irq(void)
+{
+ if (MODESEGMENT) {
+ asm volatile("sti ; hlt ; cli ; cld": : :"memory");
+ return;
+ }
+ if (CONFIG_THREADS && MainThread.next != &MainThread) {
+ // Threads still active - do a yield instead.
+ yield();
+ return;
+ }
+ extern void trampoline_waitirq();
+ struct bregs br;
+ br.flags = 0;
+ br.code.seg = SEG_BIOS;
+ br.code.offset = (u32)&trampoline_waitirq;
+ call16big(&br);