byteorder.h 1.1 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546
  1. /*
  2. * linux/include/asm-arm/byteorder.h
  3. *
  4. * ARM Endian-ness. In little endian mode, the data bus is connected such
  5. * that byte accesses appear as:
  6. * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31
  7. * and word accesses (data or instruction) appear as:
  8. * d0...d31
  9. *
  10. * When in big endian mode, byte accesses appear as:
  11. * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7
  12. * and word accesses (data or instruction) appear as:
  13. * d0...d31
  14. */
  15. #ifndef __ASM_ARM_BYTEORDER_H
  16. #define __ASM_ARM_BYTEORDER_H
  17. #include <asm/types.h>
  18. static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
  19. {
  20. __u32 t;
  21. t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
  22. x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
  23. t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
  24. x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
  25. return x;
  26. }
  27. #define __arch__swab32(x) ___arch__swab32(x)
  28. #if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
  29. # define __BYTEORDER_HAS_U64__
  30. # define __SWAB_64_THRU_32__
  31. #endif
  32. #ifdef __ARMEB__
  33. #include <linux/byteorder/big_endian.h>
  34. #else
  35. #include <linux/byteorder/little_endian.h>
  36. #endif
  37. #endif