[newlib-cygwin.git] / libgloss / m32r / crt0.S

	.text
	.balign 4
	.global	_start
_start:

	ld24	sp, _stack
	ldi	fp, #0

# Clear the BSS.  Do it in two parts for efficiency: longwords first
# for most of it, then the remaining 0 to 3 bytes.

	seth	r2, #shigh(__bss_start)
	add3	r2, r2, #low(__bss_start); R2 = start of BSS
	seth	r3, #shigh(_end)
	add3	r3, r3, #low(_end)	; R3 = end of BSS + 1
	
	sub	r3, r2		; R3 = BSS size in bytes
	mv	r4, r3
	srli	r4, #2		; R4 = BSS size in longwords (rounded down)
	ldi	r1, #0		; clear R1 for longword store
	addi	r2, #-4		; account for pre-inc store
	beqz	r4, .Lendloop1	; any more to go?
.Lloop1:
	st	r1, @+r2	; yep, zero out another longword
	addi	r4, #-1		; decrement count
	bnez	r4, .Lloop1	; go do some more
.Lendloop1:
	and3	r4, r3, #3	; get no. of remaining BSS bytes to clear
	addi	r2, #4		; account for pre-inc store
	beqz	r4, .Lendloop2	; any more to go?
.Lloop2:
	stb	r1, @r2		; yep, zero out another byte
	addi	r2, #1		; bump address
	addi	r4, #-1		; decrement count
	bnez	r4, .Lloop2	; go do some more
.Lendloop2:

# Run code in the .init section.
# This will queue the .fini section to be run with atexit.

	bl	__init

# Call main, then exit.

	bl	main
	bl	exit

# If that fails just loop.

.Lexit:
	bra	.Lexit
Commit	Line	Data
03261851 RK	1	.text
	2	.balign 4
	3	.global _start
	4	_start:
	5
	6	ld24 sp, _stack
	7	ldi fp, #0
	8
	9	# Clear the BSS. Do it in two parts for efficiency: longwords first
	10	# for most of it, then the remaining 0 to 3 bytes.
	11
	12	seth r2, #shigh(__bss_start)
	13	add3 r2, r2, #low(__bss_start); R2 = start of BSS
	14	seth r3, #shigh(_end)
	15	add3 r3, r3, #low(_end) ; R3 = end of BSS + 1
	16
	17	sub r3, r2 ; R3 = BSS size in bytes
	18	mv r4, r3
	19	srli r4, #2 ; R4 = BSS size in longwords (rounded down)
	20	ldi r1, #0 ; clear R1 for longword store
	21	addi r2, #-4 ; account for pre-inc store
	22	beqz r4, .Lendloop1 ; any more to go?
	23	.Lloop1:
	24	st r1, @+r2 ; yep, zero out another longword
	25	addi r4, #-1 ; decrement count
	26	bnez r4, .Lloop1 ; go do some more
	27	.Lendloop1:
	28	and3 r4, r3, #3 ; get no. of remaining BSS bytes to clear
	29	addi r2, #4 ; account for pre-inc store
	30	beqz r4, .Lendloop2 ; any more to go?
	31	.Lloop2:
	32	stb r1, @r2 ; yep, zero out another byte
	33	addi r2, #1 ; bump address
	34	addi r4, #-1 ; decrement count
	35	bnez r4, .Lloop2 ; go do some more
	36	.Lendloop2:
	37
	38	# Run code in the .init section.
	39	# This will queue the .fini section to be run with atexit.
	40
	41	bl __init
	42
	43	# Call main, then exit.
	44
	45	bl main
	46	bl exit
	47
	48	# If that fails just loop.
	49
	50	.Lexit:
	51	bra .Lexit