//******************************************************* //* 2007.6.18 //******************************************************* 在 /kernel/include/asm-arm/arch-s3c2410/bitfield.h 文件中： #ifndef __ASSEMBLY__ #define UData(Data) ((unsigned long) (Data)) #else #define UData(Data) (Data) #endif 例：UData(5); = 5 /* * MACRO: Fld * * Purpose * The macro "Fld" encodes a bit field, given its size and its shift value * with respect to bit 0. * * Note * A more intuitive way to encode bit fields would have been to use their * mask. However, extracting size and shift value information from a bit * field''''s mask is cumbersome and might break the assembler (255-character * line-size limit). * * Input * Size Size of the bit field, in number of bits. * Shft Shift value of the bit field with respect to bit 0. * * Output * Fld Encoded bit field. */ #define Fld(Size, Shft) (((Size) << 16) + (Shft)) 例：Fld(2,5); = 0x20005 /* * MACROS: FSize, FShft, FMsk, FAlnMsk, F1stBit * * Purpose * The macros "FSize", "FShft", "FMsk", "FAlnMsk", and "F1stBit" return * the size, shift value, mask, aligned mask, and first bit of a * bit field. * * Input * Field Encoded bit field (using the macro "Fld"). * * Output * FSize Size of the bit field, in number of bits. * FShft Shift value of the bit field with respect to bit 0. * FMsk Mask for the bit field. * FAlnMsk Mask for the bit field, aligned on bit 0. * F1stBit First bit of the bit field. */ #define FSize(Field) ((Field) >> 16) 例：FSize(0x20005); = 2 #define FShft(Field) ((Field) & 0x0000FFFF) 例：FShft(0x20005); = 5 /* * MACRO: FInsrt * * Purpose * The macro "FInsrt" inserts a value into a bit field by shifting the * former appropriately. * * Input * Valu...
