ABS
#define ABS(a) \
#define ABS(A) ((A) >= 0 ? (A) : -(A))
#define ABS(x) (x-_start+0x7c00)
# define ABS(x) ((x) - EXT_C(main) + 0x2200)
# define ABS(x) ((x) - EXT_C(main) + 0x8200)
# define ABS(x) (x-_start+0x2000)
# define ABS(x) (x-_start+0x8000)
#define ABS(x) (x-_start+BOOTSEC_LOCATION)
#define ABS(x) ((x) < (0) ? (-(x)) : (x))
#define ABS(x) ((x) < 0 ? -(x) : (x))
#define ABS(a) ((a) < 0 ? -(a) : (a))
#define ABS(x) ((x) < (0) ? (-(x)) : (x))