xref: /nrf52832-nimble/rt-thread/libcpu/arm/armv6/vfp.c (revision 104654410c56c573564690304ae786df310c91fc)
1*10465441SEvalZero /*
2*10465441SEvalZero  * Copyright (c) 2006-2018, RT-Thread Development Team
3*10465441SEvalZero  *
4*10465441SEvalZero  * SPDX-License-Identifier: Apache-2.0
5*10465441SEvalZero  *
6*10465441SEvalZero  * Change Logs:
7*10465441SEvalZero  * Date           Author       Notes
8*10465441SEvalZero  * 2014-11-07     weety      first version
9*10465441SEvalZero  */
10*10465441SEvalZero 
11*10465441SEvalZero #include <rthw.h>
12*10465441SEvalZero #include <rtthread.h>
13*10465441SEvalZero #include "vfp.h"
14*10465441SEvalZero 
15*10465441SEvalZero #ifdef RT_USING_VFP
16*10465441SEvalZero 
vfp_init(void)17*10465441SEvalZero void vfp_init(void)
18*10465441SEvalZero {
19*10465441SEvalZero     int ret = 0;
20*10465441SEvalZero     unsigned int value;
21*10465441SEvalZero     asm  volatile ("mrc p15, 0, %0, c1, c0, 2"
22*10465441SEvalZero             :"=r"(value)
23*10465441SEvalZero             :);
24*10465441SEvalZero     value |= 0xf00000;/*enable CP10, CP11 user access*/
25*10465441SEvalZero     asm volatile("mcr p15, 0, %0, c1, c0, 2"
26*10465441SEvalZero             :
27*10465441SEvalZero             :"r"(value));
28*10465441SEvalZero 
29*10465441SEvalZero     asm volatile("fmrx %0, fpexc"
30*10465441SEvalZero             :"=r"(value));
31*10465441SEvalZero     value |=(1<<30);
32*10465441SEvalZero     asm volatile("fmxr fpexc, %0"
33*10465441SEvalZero             :
34*10465441SEvalZero             :"r"(value));
35*10465441SEvalZero 
36*10465441SEvalZero }
37*10465441SEvalZero 
38*10465441SEvalZero #endif
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