A20, E820h, Real Mode Emulation

1 files changed, 17 insertions, 0 deletions

diff --git a/src/loader/cpu.c b/src/loader/cpu.c
index a0694ed..d5b56df 100644
--- a/src/loader/cpu.c
+++ b/src/loader/cpu.c
@@ -41,3 +41,20 @@ void outl(u16 port, u32 data)
 {
 	__asm__ volatile("outl %0, %1" ::"a"(data), "Nd"(port));
 }
+
+/**
+ * Move memory
+ */
+
+#define WORD_PTR(PTR) (*((u16 *)(PTR)))
+u16 mminw(u32 addr)
+{
+	u16 ret;
+	__asm__ volatile("movw %1, %0" : "=r"(ret) : "m"(WORD_PTR(addr)) : "memory");
+	return ret;
+}
+
+void mmoutw(u32 addr, u16 value)
+{
+	__asm__ volatile("movw %1, %0" : "=m"(WORD_PTR(addr)) : "ir"(value) : "memory");
+}