From f78cb404aa995f7b1bc000ef41078fa3e8814807 Mon Sep 17 00:00:00 2001
From: zerico <71151164+ZERICO2005@users.noreply.github.com>
Date: Thu, 26 Feb 2026 15:30:38 -0700
Subject: [PATCH 1/2] size optimized bss_zeroize

---
 src/crt/crt0.S | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/src/crt/crt0.S b/src/crt/crt0.S
index 12b4c7ce1..0f04a9319 100644
--- a/src/crt/crt0.S
+++ b/src/crt/crt0.S
@@ -174,23 +174,16 @@ ___libload_libs_ret:
 	di
 
 .L.bss_zeroize:
-	ld	hl, ___bss_len
-	ld	bc, 0
+	ld	bc, ___bss_len + 1
+	ld	hl, ___bss_low - 1
 	xor	a, a
-	sbc	hl, bc
-	jr	z, .L.bss_done
-	ld	de, ___bss_low
-	push	de
-	ld	(de), a
-	dec	hl
-	sbc	hl, bc
-	pop	hl
-	jr	z, .L.bss_done
-	ld	bc, ___bss_len
-	dec	bc
-	inc	de
-	ldir
-.L.bss_done:
+	db	$E6				; and a, $77 (clears carry)
+	; jr	.L.bss_start
+.L.bss_loop:					; 7F + 1R + 1W + 1
+	ld	(hl), a
+; .L.bss_start:
+	cpi
+	jp	pe, .L.bss_loop
 
 	res	1, (iy + 0x0D)			; no text buffer
 	res	3, (iy + 0x4A)			; use first shadow buffer

From 93e80674940ebcc6bfe1ba377ae3a3791d780235 Mon Sep 17 00:00:00 2001
From: zerico <71151164+ZERICO2005@users.noreply.github.com>
Date: Thu, 26 Feb 2026 15:51:32 -0700
Subject: [PATCH 2/2] use ti.boot.memclear to zeroize bss

---
 src/crt/crt0.S | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/crt/crt0.S b/src/crt/crt0.S
index 0f04a9319..3a7112997 100644
--- a/src/crt/crt0.S
+++ b/src/crt/crt0.S
@@ -37,6 +37,7 @@
 	.equ	ti.PopRealO1, 0x0205DC
 	.equ	ti.MovFrOP1, 0x02032C
 	.equ	ti.ClrLCDFull, 0x020808
+	.equ	ti.boot.memclear, 0x0000B0
 
 	.section	.header,"ax",@progbits
 
@@ -173,17 +174,15 @@ ___libload_libs_ret:
 	call	ti.usb_DisableTimer
 	di
 
-.L.bss_zeroize:
-	ld	bc, ___bss_len + 1
-	ld	hl, ___bss_low - 1
-	xor	a, a
-	db	$E6				; and a, $77 (clears carry)
-	; jr	.L.bss_start
-.L.bss_loop:					; 7F + 1R + 1W + 1
-	ld	(hl), a
-; .L.bss_start:
-	cpi
-	jp	pe, .L.bss_loop
+	; zeroize bss
+	ld	hl, ___bss_low
+	ld	bc, ___bss_len
+	push	bc
+	push	hl
+	; void memclear(void *dst, size_t size)
+	call	ti.boot.memclear
+	pop	hl
+	pop	hl
 
 	res	1, (iy + 0x0D)			; no text buffer
 	res	3, (iy + 0x4A)			; use first shadow buffer