160 lines
3.4 KiB
C
160 lines
3.4 KiB
C
/*
|
|
* Copyright (c) 2011-2020, Shanghai Real-Thread Electronic Technology Co.,Ltd
|
|
*
|
|
* Change Logs:
|
|
* Date Author Notes
|
|
* 2020-12-18 quanzhao the first version
|
|
*/
|
|
|
|
#include <time.h>
|
|
#include <string.h>
|
|
#include <rtthread.h>
|
|
|
|
static struct rt_device random_dev;
|
|
static unsigned long seed;
|
|
|
|
static rt_uint16_t calc_random(void)
|
|
{
|
|
seed = 214013L * seed + 2531011L;
|
|
return (seed >> 16) & 0x7FFF; /* return bits 16~30 */
|
|
}
|
|
|
|
static rt_ssize_t random_read(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
|
|
{
|
|
rt_uint16_t rand = calc_random();
|
|
ssize_t ret = sizeof(rand);
|
|
rt_memcpy(buffer, &rand, ret);
|
|
return ret;
|
|
}
|
|
|
|
static rt_ssize_t random_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
|
|
{
|
|
ssize_t ret = sizeof(seed);
|
|
rt_memcpy(&seed, buffer, ret);
|
|
return ret;
|
|
}
|
|
|
|
static rt_err_t random_control(rt_device_t dev, int cmd, void *args)
|
|
{
|
|
return RT_EOK;
|
|
}
|
|
|
|
#ifdef RT_USING_DEVICE_OPS
|
|
const static struct rt_device_ops random_ops =
|
|
{
|
|
RT_NULL,
|
|
RT_NULL,
|
|
RT_NULL,
|
|
random_read,
|
|
random_write,
|
|
random_control
|
|
};
|
|
#endif
|
|
|
|
int random_device_init(void)
|
|
{
|
|
static rt_bool_t init_ok = RT_FALSE;
|
|
|
|
if (init_ok)
|
|
{
|
|
return 0;
|
|
}
|
|
RT_ASSERT(!rt_device_find("random"));
|
|
random_dev.type = RT_Device_Class_Miscellaneous;
|
|
|
|
#ifdef RT_USING_DEVICE_OPS
|
|
random_dev.ops = &random_ops;
|
|
#else
|
|
random_dev.init = RT_NULL;
|
|
random_dev.open = RT_NULL;
|
|
random_dev.close = RT_NULL;
|
|
random_dev.read = random_read;
|
|
random_dev.write = random_write;
|
|
random_dev.control = random_control;
|
|
#endif
|
|
|
|
/* no private */
|
|
random_dev.user_data = RT_NULL;
|
|
|
|
rt_device_register(&random_dev, "random", RT_DEVICE_FLAG_RDWR);
|
|
|
|
init_ok = RT_TRUE;
|
|
|
|
return 0;
|
|
}
|
|
INIT_DEVICE_EXPORT(random_device_init);
|
|
|
|
static struct rt_device urandom_dev;
|
|
static unsigned long useed;
|
|
|
|
static rt_uint16_t calc_urandom(void)
|
|
{
|
|
useed = 214013L * useed + 2531011L;
|
|
return (useed >> 16) & 0x7FFF; /* return bits 16~30 */
|
|
}
|
|
|
|
static rt_ssize_t random_uread(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
|
|
{
|
|
rt_uint16_t rand = calc_urandom();
|
|
ssize_t ret = sizeof(rand);
|
|
rt_memcpy(buffer, &rand, ret);
|
|
return ret;
|
|
}
|
|
|
|
static rt_ssize_t random_uwrite(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
|
|
{
|
|
ssize_t ret = sizeof(useed);
|
|
rt_memcpy(&useed, buffer, ret);
|
|
return ret;
|
|
}
|
|
|
|
static rt_err_t random_ucontrol(rt_device_t dev, int cmd, void *args)
|
|
{
|
|
return RT_EOK;
|
|
}
|
|
|
|
#ifdef RT_USING_DEVICE_OPS
|
|
const static struct rt_device_ops urandom_ops =
|
|
{
|
|
RT_NULL,
|
|
RT_NULL,
|
|
RT_NULL,
|
|
random_uread,
|
|
random_uwrite,
|
|
random_ucontrol
|
|
};
|
|
#endif
|
|
|
|
int urandom_device_init(void)
|
|
{
|
|
static rt_bool_t init_ok = RT_FALSE;
|
|
|
|
if (init_ok)
|
|
{
|
|
return 0;
|
|
}
|
|
RT_ASSERT(!rt_device_find("urandom"));
|
|
urandom_dev.type = RT_Device_Class_Miscellaneous;
|
|
|
|
#ifdef RT_USING_DEVICE_OPS
|
|
urandom_dev.ops = &urandom_ops;
|
|
#else
|
|
urandom_dev.init = RT_NULL;
|
|
urandom_dev.open = RT_NULL;
|
|
urandom_dev.close = RT_NULL;
|
|
urandom_dev.read = random_uread;
|
|
urandom_dev.write = random_uwrite;
|
|
urandom_dev.control = random_ucontrol;
|
|
#endif
|
|
|
|
/* no private */
|
|
urandom_dev.user_data = RT_NULL;
|
|
|
|
rt_device_register(&urandom_dev, "urandom", RT_DEVICE_FLAG_RDWR);
|
|
|
|
init_ok = RT_TRUE;
|
|
|
|
return 0;
|
|
}
|
|
INIT_DEVICE_EXPORT(urandom_device_init);
|