What is different about the assembler as(1)?
BSD/OS 4.0 uses GNU as 2.8.1. Previous releases of BSD/OS used GNU as 1.38. GNU as version 2 contains many bug fixes and new features. In particular, GNU as version 2 handles Pentium and later opcodes, and has a .code16 pseudo-op for 8086-mode coding. For a full description of the features of GNU as version 2, see the manual, which can be accessed on-line using `info as’. The assembler now accepts a superset of ELF and a.out pseudo-ops. Where there is ambiguity, the assembler uses the ELF semantics. Since ELF supports more features, particularly in the area of alignment, some pseudo-ops have features that were not previously available or useful. One area of ambiguity is the .align pseudo-op. Formerly, the argument to .align was an exponent; for example, .align 2 caused 4-byte alignment, because 2 to the 2nd power is 4. With ELF, the argument to .align is simply the number of bytes; hence, .align 2 produces 2-byte alignment. If you still want to use a power-of-2 alignment argument, you
