귀하신 emacs를 전체 화면으로 시작

(setq initial-frame-alist '((fullscreen . maximized)))

emacs처럼 귀하신 분은 크게 모셔야 한다. initial-frame-alist 변수를 수정하면 최대 화면으로 시작하게 할 수 있다.

(defun toggle-frame-maximized (&optional frame)
  "Toggle maximization state of FRAME.
Maximize selected frame or un-maximize if it is already maximized.

If the frame is in fullscreen state, don't change its state, but
set the frame's `fullscreen-restore' parameter to `maximized', so
the frame will be maximized after disabling fullscreen state.

Note that with some window managers you may have to set
`frame-resize-pixelwise' to non-nil in order to make a frame
appear truly maximized.  In addition, you may have to set
`x-frame-normalize-before-maximize' in order to enable
transitions from one fullscreen state to another.

See also `toggle-frame-fullscreen'."
  (interactive)
  (let ((fullscreen (frame-parameter frame 'fullscreen)))
    (cond
     ((memq fullscreen '(fullscreen fullboth))
      (set-frame-parameter frame 'fullscreen-restore 'maximized))
     ((eq fullscreen 'maximized)
      (set-frame-parameter frame 'fullscreen nil))
     (t
      (set-frame-parameter frame 'fullscreen 'maximized)))))

initial-frame-alist 변수 설명에 fullscreen, maximized 심볼 설명이 없어서 찾아봤는데, 소스 코드에서 발견했다. 소스 코드를 수시로 보는 게 아니면 이런 심볼은 누가 알려줘야 알 수 있을 것 같다.

링크 - Vim to Emacs’ Evil chaotic migration guide

C-x C-s C-x C-c