[avrcpm.git] / avr / heap.asm

;    Simple memory management module.
;
;    Copyright (C) 2010 Leo C.
;
;    This file is part of avrcpm.
;
;    avrcpm 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 3 of the License, or
;    (at your option) any later version.
;
;    avrcpm 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 avrcpm.  If not, see <http://www.gnu.org/licenses/>.
;
;    $Id$
;


	.dseg
hp_top: .byte	2

	.cseg

.if HEAP_DEBUG
hp_print_free:
	push	r15
	push	r14
	push	temp2
	push	temp
	printstring ", bytes free: "
	lds	r14,hp_top
	lds	r15,hp_top+1
	ldi	temp,0
	ldi	temp2,0
	sub	temp,r14
	sbc	temp2,r15
	clr	r14
	clr	r15
	rcall	print_ultoa
	printstring " "
	pop	temp
	pop	temp2
	pop	r14
	pop	r15
	ret
.endif		


; Init heap
; temp:temp2 = first free memory location (heap start)

heap_init:
.if HEAP_DEBUG
	printnewline
	printstring "Heap init: Start: "
	rjmp	hp_dbg1
.endif		
heap_release:
.if HEAP_DEBUG
	printnewline
	printstring "Heap release: Start: "
hp_dbg1:
.endif		
	sts	hp_top,temp
	sts	hp_top+1,temp2
.if HEAP_DEBUG
	rcall	printhexw
	rcall	hp_print_free
.endif		
	ret

; Get memory block from heap.
; temp2:temp = size of block
; return temp2:temp = pointer to allocated block
; return 0 if not enough space

heap_get:
	push	r15
	push	r14
.if HEAP_DEBUG
	push	temp2
	push	temp
	printnewline
	printstring "Heap get: "
	clr	r14
	clr	r15
	rcall	print_ultoa
	pop	temp
	pop	temp2	
.endif		
	lds	r14,hp_top
	lds	r15,hp_top+1
	add	temp,r14
	adc	temp2,r15
	brcs	hp_full
		
; zero flag clear here

	sts	hp_top,temp
	sts	hp_top+1,temp2
	movw	temp,r14
	rjmp	hp_get_ex
hp_full:
	clr	temp
	clr	temp2		;(sets zero flag)
hp_get_ex:
.if HEAP_DEBUG
	brne	hp_get_dbg1
	printstring "Error: "
hp_get_dbg1:
	rcall	hp_print_free
	mov	r14,temp	;restore zero flag
	or	r14,temp2
.endif
	pop	r14
	pop	r15
	ret


; vim:set ts=8 noet nowrap
Commit	Line	Data
a17b9bbb L	1	; Simple memory management module.
	2	;
	3	; Copyright (C) 2010 Leo C.
	4	;
	5	; This file is part of avrcpm.
	6	;
	7	; avrcpm is free software: you can redistribute it and/or modify it
	8	; under the terms of the GNU General Public License as published by
	9	; the Free Software Foundation, either version 3 of the License, or
	10	; (at your option) any later version.
	11	;
	12	; avrcpm is distributed in the hope that it will be useful,
	13	; but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	; GNU General Public License for more details.
	16	;
	17	; You should have received a copy of the GNU General Public License
	18	; along with avrcpm. If not, see <http://www.gnu.org/licenses/>.
	19	;
	20	; $Id$
	21	;
	22
	23
	24	.dseg
	25	hp_top: .byte 2
	26
	27	.cseg
	28
	29	.if HEAP_DEBUG
	30	hp_print_free:
825ecc9d L	31	push r15
825ecc9d L	32	push r14
a17b9bbb L	33	push temp2
	34	push temp
	35	printstring ", bytes free: "
825ecc9d L	36	lds r14,hp_top
825ecc9d L	37	lds r15,hp_top+1
a17b9bbb L	38	ldi temp,0
a17b9bbb L	39	ldi temp2,0
825ecc9d L	40	sub temp,r14
	41	sbc temp2,r15
	42	clr r14
	43	clr r15
a17b9bbb L	44	rcall print_ultoa
	45	printstring " "
	46	pop temp
	47	pop temp2
825ecc9d L	48	pop r14
825ecc9d L	49	pop r15
a17b9bbb L	50	ret
	51	.endif
	52
	53
	54	; Init heap
	55	; temp:temp2 = first free memory location (heap start)
	56
	57	heap_init:
	58	.if HEAP_DEBUG
	59	printnewline
	60	printstring "Heap init: Start: "
	61	rjmp hp_dbg1
	62	.endif
	63	heap_release:
	64	.if HEAP_DEBUG
	65	printnewline
	66	printstring "Heap release: Start: "
	67	hp_dbg1:
	68	.endif
	69	sts hp_top,temp
	70	sts hp_top+1,temp2
	71	.if HEAP_DEBUG
	72	rcall printhexw
	73	rcall hp_print_free
	74	.endif
	75	ret
	76
	77	; Get memory block from heap.
	78	; temp2:temp = size of block
	79	; return temp2:temp = pointer to allocated block
	80	; return 0 if not enough space
	81
	82	heap_get:
825ecc9d L	83	push r15
825ecc9d L	84	push r14
a17b9bbb L	85	.if HEAP_DEBUG
	86	push temp2
	87	push temp
	88	printnewline
	89	printstring "Heap get: "
825ecc9d L	90	clr r14
825ecc9d L	91	clr r15
a17b9bbb L	92	rcall print_ultoa
	93	pop temp
	94	pop temp2
	95	.endif
825ecc9d L	96	lds r14,hp_top
	97	lds r15,hp_top+1
	98	add temp,r14
	99	adc temp2,r15
a17b9bbb L	100	brcs hp_full
	101
	102	; zero flag clear here
	103
	104	sts hp_top,temp
	105	sts hp_top+1,temp2
825ecc9d	106	movw temp,r14
a17b9bbb L	107	rjmp hp_get_ex
	108	hp_full:
	109	clr temp
	110	clr temp2 ;(sets zero flag)
	111	hp_get_ex:
	112	.if HEAP_DEBUG
	113	brne hp_get_dbg1
	114	printstring "Error: "
	115	hp_get_dbg1:
	116	rcall hp_print_free
825ecc9d L	117	mov r14,temp ;restore zero flag
825ecc9d L	118	or r14,temp2
a17b9bbb	119	.endif
825ecc9d L	120	pop r14
825ecc9d L	121	pop r15
a17b9bbb L	122	ret
	123
	124
	125	; vim:set ts=8 noet nowrap
	126