diff options
Diffstat (limited to 'qemu/roms/u-boot/lib/rand.c')
-rw-r--r-- | qemu/roms/u-boot/lib/rand.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/lib/rand.c b/qemu/roms/u-boot/lib/rand.c new file mode 100644 index 000000000..5c367e186 --- /dev/null +++ b/qemu/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; +} |