Asm mode is a major mode for editing files of assembler code. It defines these commands:
tab-to-tab-stop.
Insert a newline and then indent using tab-to-tab-stop.
Insert a colon and then remove the indentation from before the label
preceding colon. Then do tab-to-tab-stop.
Insert or align a comment.
The variable asm-comment-char specifies which character
starts comments in assembler syntax.