From 9d2021cf1f374da5a23e49cbc2c0040c8ac558e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Mon, 13 Mar 2023 14:40:28 +0200
Subject: [PATCH] Reset disk system on read error

---
 ponydos.asm | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/ponydos.asm b/ponydos.asm
index 9b1d8b6..3a9dc5e 100644
--- a/ponydos.asm
+++ b/ponydos.asm
@@ -214,8 +214,10 @@ read_sector:
 	; es:bx = output buffer
 	mov bx, di
 
+	.retry:
 	mov ax, 0x0201 ; read one sector
 	int 0x13
+	jc .error
 
 	pop dx
 	pop cx
@@ -223,6 +225,14 @@ read_sector:
 	pop ax
 	ret
 
+	.error:
+		; Reset the disk system unconditinoally, as we have no
+		; kernel panic handler to go to after 3 tries and proper
+		; error handling would take too much code
+		xor ah, ah
+		int 0x10
+		jmp .retry
+
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