diff options
author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
---|---|---|
committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
tree | 65ca85f13617aee1dce474596800950f266a456c /roms/u-boot/lib/rand.c | |
download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip |
Diffstat (limited to 'roms/u-boot/lib/rand.c')
-rw-r--r-- | roms/u-boot/lib/rand.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/roms/u-boot/lib/rand.c b/roms/u-boot/lib/rand.c new file mode 100644 index 00000000..5c367e18 --- /dev/null +++ b/roms/u-boot/lib/rand.c @@ -0,0 +1,32 @@ +/* + * Simple xorshift PRNG + * see http://www.jstatsoft.org/v08/i14/paper + * + * Copyright (c) 2012 Michael Walle + * Michael Walle <michael@walle.cc> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> + +static unsigned int y = 1U; + +unsigned int rand_r(unsigned int *seedp) +{ + *seedp ^= (*seedp << 13); + *seedp ^= (*seedp >> 17); + *seedp ^= (*seedp << 5); + + return *seedp; +} + +unsigned int rand(void) +{ + return rand_r(&y); +} + +void srand(unsigned int seed) +{ + y = seed; +} |