From 7ecfe48b19c3e97341a3f2b0d85e7367ab92f2b6 Mon Sep 17 00:00:00 2001 From: Marc Schink Date: Thu, 17 Mar 2016 16:07:23 +0100 Subject: helpers: Add reverse_byte() and reverse_bytes() Change-Id: I9d2e1e2856c835d22eed3b3a34bc0379773dd831 Signed-off-by: Marc Schink Reviewed-on: https://review.coreboot.org/28086 Tested-by: build bot (Jenkins) Reviewed-by: Nico Huber --- helpers.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'helpers.c') diff --git a/helpers.c b/helpers.c index 2fcda65c6..a714908b7 100644 --- a/helpers.c +++ b/helpers.c @@ -66,6 +66,23 @@ void tolower_string(char *str) *str = (char)tolower((unsigned char)*str); } +uint8_t reverse_byte(uint8_t x) +{ + x = ((x >> 1) & 0x55) | ((x << 1) & 0xaa); + x = ((x >> 2) & 0x33) | ((x << 2) & 0xcc); + x = ((x >> 4) & 0x0f) | ((x << 4) & 0xf0); + + return x; +} + +void reverse_bytes(uint8_t *dst, const uint8_t *src, size_t length) +{ + size_t i; + + for (i = 0; i < length; i++) + dst[i] = reverse_byte(src[i]); +} + /* FIXME: Find a better solution for MinGW. Maybe wrap strtok_s (C11) if it becomes available */ #ifdef __MINGW32__ char* strtok_r(char *str, const char *delim, char **nextp) -- cgit v1.2.3