8b883a61a3
Instead of every hardware number generator driver providing an implementation of this function, use the random device API to centralize the implementation of this function. This is a very simplistic function that can be seen as a stepping stone to refactor the random number generation in Zephyr. Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
41 lines
981 B
C
41 lines
981 B
C
/*
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* Copyright (c) 2017 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <atomic.h>
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#include <kernel.h>
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#include <entropy.h>
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static atomic_t entropy_driver;
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u32_t sys_rand32_get(void)
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{
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struct device *dev = (struct device *)atomic_get(&entropy_driver);
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u32_t random_num;
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int ret;
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if (unlikely(!dev)) {
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/* Only one entropy device exists, so this is safe even
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* if the whole operation isn't atomic.
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*/
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dev = device_get_binding(CONFIG_ENTROPY_NAME);
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atomic_set(&entropy_driver, (atomic_t)(uintptr_t)dev);
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}
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ret = entropy_get_entropy(dev, (u8_t *)&random_num,
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sizeof(random_num));
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if (unlikely(ret < 0)) {
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/* Use system timer in case the entropy device couldn't deliver
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* 32-bit of data. There's not much that can be done in this
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* situation. An __ASSERT() isn't used here as the HWRNG might
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* still be gathering entropy during early boot situations.
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*/
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random_num = k_cycle_get_32();
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}
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return random_num;
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}
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