lots of stuff

1 files changed, 25 insertions, 0 deletions

diff --git a/kernel/fpu.c b/kernel/fpu.c
new file mode 100644
index 0000000..f5512d6
--- /dev/null
+++ b/kernel/fpu.c
@@ -0,0 +1,25 @@
+/* Copyright (C) 2011-2013 Kevin Lange */
+/* this code from toaruos */
+#include <stddef.h>
+#include "fpu.h"
+
+/**
+ * Enable the FPU and SSE
+ */
+void fpu_enable(void) {
+        asm volatile ("clts");
+        size_t t;
+        asm volatile ("mov %%cr4, %0" : "=r"(t));
+        t |= 3 << 9;
+        asm volatile ("mov %0, %%cr4" :: "r"(t));
+}
+
+/**
+ * Disable FPU and SSE so it traps to the kernel
+ */
+void fpu_disable(void) {
+        size_t t;
+        asm volatile ("mov %%cr0, %0" : "=r"(t));
+        t |= 1 << 3;
+        asm volatile ("mov %0, %%cr0" :: "r"(t));
+}