From 0d7cde7c4d735ebebd39b988440f50f5889bd29f Mon Sep 17 00:00:00 2001 From: Franklin Wei Date: Sun, 8 Feb 2015 12:15:06 -0500 Subject: lots of stuff --- kernel/fpu.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 kernel/fpu.c (limited to 'kernel/fpu.c') 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 +#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)); +} -- cgit v1.1