[ECOS] C Preprocessing Directive in assembler

twomol twomol@bj1860.net
Wed Nov 10 07:10:00 GMT 2004


hello			
         I'm a new guy to ecos,when I read the source of ecos ,I was puzzled.For example,
the vector.s in the hal\arm\arch\v2_0\src directory:

 #ifdef CYGSEM_HAL_ROM_RESET_USES_JUMP
// Assumption:  ROM code has these vectors at the hardware reset address.
// A simple jump removes any address-space dependencies [i.e. safer]
        b       reset_vector                    // 0x00
#else
        ldr     pc,.reset_vector                // 0x00
#endif
        ldr     pc,.undefined_instruction       // 0x04
        ldr     pc,.software_interrupt          // 0x08 start && software int


the "#ifdef CYGSEM_HAL_ROM_RESET_USES_JUMP"  is a  c/c++ language Preprocessing Directive,how dose it affect the assembler.
      Thanks very very very  much!



        twomol
        twomol@bj1860.net
          2004-11-10



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