;--------------------------------------------------------------------------
;  __initrleblock.s
;
;  Copyright (C) 2001, Michael Hope
;  Copyright (C) 2020, Sergey Belyashov
;
;  This library is free software; you can redistribute it and/or modify it
;  under the terms of the GNU General Public License as published by the
;  Free Software Foundation; either version 2, or (at your option) any
;  later version.
;
;  This library is distributed in the hope that it will be useful,
;  but WITHOUT ANY WARRANTY; without even the implied warranty of
;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;  GNU General Public License for more details.
;
;  You should have received a copy of the GNU General Public License 
;  along with this library; see the file COPYING. If not, write to the
;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
;   MA 02110-1301, USA.
;
;  As a special exception, if you link this library with other files,
;  some of which are compiled with SDCC, to produce an executable,
;  this library does not by itself cause the resulting executable to
;  be covered by the GNU General Public License. This exception does
;  not however invalidate any other reasons why the executable file
;   might be covered by the GNU General Public License.
;--------------------------------------------------------------------------

	.area   _CODE

	;; Special RLE decoder used for initing global data
	;; input: DE - destination address
__initrleblock::
	;; Pop the return address
	pop	hl
1$:
	;; Fetch the run
	ld	a, (hl+)
	ld	c, a
	;; Negative means a run
	bit	7, c
	jr	Z, 2$
	;; Expanding a run
	ld	a, (hl+)
3$:
	ld	(de), a
	inc	de
	inc	c
	jr	NZ, 3$
	jr	1$
2$:
	;; Zero means end of a block
	inc	c
	dec	c
	jr	Z, 4$
	;; Expanding a block
5$:
	ld	a, (hl+)
	ld	(de), a
	inc	de
	dec	c
	jr	NZ, 5$
	jr	1$
4$:
	;; Return back
	jp	(hl)
