diff options
author | Harald Welte <laforge@gnumonks.org> | 2010-03-07 19:05:13 +0100 |
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committer | Harald Welte <laforge@gnumonks.org> | 2010-03-07 19:05:13 +0100 |
commit | ff6ffe5677e080ad25eb31d3b8f55e4265069a8b (patch) | |
tree | 6dfc9a20fe21a6c56cbf1e35f4ba23fd4f5b3fd8 /src/target/firmware/include/asm | |
parent | 3e9d0ba838419888b0edd282f80667bc6f0a8a39 (diff) |
import byte-ordering defines/macros from linux
Diffstat (limited to 'src/target/firmware/include/asm')
-rw-r--r-- | src/target/firmware/include/asm/swab.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/target/firmware/include/asm/swab.h b/src/target/firmware/include/asm/swab.h new file mode 100644 index 00000000..4640e271 --- /dev/null +++ b/src/target/firmware/include/asm/swab.h @@ -0,0 +1,45 @@ +/* + * arch/arm/include/asm/byteorder.h + * + * ARM Endian-ness. In little endian mode, the data bus is connected such + * that byte accesses appear as: + * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31 + * and word accesses (data or instruction) appear as: + * d0...d31 + * + * When in big endian mode, byte accesses appear as: + * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7 + * and word accesses (data or instruction) appear as: + * d0...d31 + */ +#ifndef __ASM_ARM_SWAB_H +#define __ASM_ARM_SWAB_H + +#include <stdint.h> +#include <defines.h> + +static inline uint32_t __arch_swab32(uint32_t x) +{ + uint32_t t; + +#ifndef __thumb__ + if (!__builtin_constant_p(x)) { + /* + * The compiler needs a bit of a hint here to always do the + * right thing and not screw it up to different degrees + * depending on the gcc version. + */ + asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x)); + } else +#endif + t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */ + + x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */ + t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */ + x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */ + + return x; +} +#define __arch_swab32 __arch_swab32 + +#endif |