From 5e31de0bacad045ffb555323c6211b871af66b9e Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Sun, 16 Jun 2019 20:53:21 -0400
Subject: [PATCH] apps/memt: new app

---
 apps/memt/glue.asm | 20 ++++++++++++++++++++
 apps/memt/main.asm | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 apps/memt/glue.asm
 create mode 100644 apps/memt/main.asm

diff --git a/apps/memt/glue.asm b/apps/memt/glue.asm
new file mode 100644
index 0000000..ec1f1f0
--- /dev/null
+++ b/apps/memt/glue.asm
@@ -0,0 +1,20 @@
+; memt
+;
+; Write all possible values in all possible addresses that follow the end of
+; this program. That means we don't test all available RAM, but well, still
+; better than nothing...
+;
+; If there's an error, prints out where.
+;
+; *** Requirements ***
+; printstr
+; printHexPair
+;
+; *** Includes ***
+
+#include "user.h"
+.org	USER_CODE
+
+jp	memtMain
+
+#include "memt/main.asm"
diff --git a/apps/memt/main.asm b/apps/memt/main.asm
new file mode 100644
index 0000000..62bd30c
--- /dev/null
+++ b/apps/memt/main.asm
@@ -0,0 +1,33 @@
+memtMain:
+	ld	de, memtEnd
+.loop:
+	ld	b, 0
+.iloop:
+	ld	a, b
+	ld	(de), a
+	ld	a, (de)
+	cp	b
+	jr	nz, .notMatching
+	djnz	.iloop
+	inc	de
+	xor	a
+	cp	d
+	jr	nz, .loop
+	cp	e
+	jr	nz, .loop
+	; we rolled over 0xffff, stop
+	ld	hl, .sOk
+	xor	a
+	jp	printstr	; returns
+.notMatching:
+	ld	hl, .sNotMatching
+	call	printstr
+	ex	de, hl
+	ld	a, 1
+	jp	printHexPair	; returns
+.sNotMatching:
+	.db	"Not matching at pos ", 0xd, 0xa, 0
+.sOk:
+	.db	"OK", 0xd, 0xa, 0
+memtEnd:
+