From: gameblabla <gameblabla@openmailbox.org>
Date: Wed, 17 Jul 2019 23:55:57 +0000 (+0200)
Subject: psxbios: Add checks for card_write, card_read
X-Git-Tag: r23~156^2~46
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd48ba5ea8c87bf8c771550bc5320f7e6f73c9a6;p=pcsx_rearmed.git

psxbios: Add checks for card_write, card_read

This also implements a bug which allows writes to 0x400
(Is supposed to only accept sector number between 0..3FFh).
Function should return 0 if sector is invalid.
---

diff --git a/libpcsxcore/psxbios.c b/libpcsxcore/psxbios.c
index 265dbfd3..d4a38e18 100644
--- a/libpcsxcore/psxbios.c
+++ b/libpcsxcore/psxbios.c
@@ -2146,7 +2146,13 @@ void psxBios__card_write() { // 0x4e
 #ifdef PSXBIOS_LOG
 	PSXBIOS_LOG("psxBios_%s: %x,%x,%x\n", biosB0n[0x4e], a0, a1, a2);
 #endif
-
+	/* Function also accepts sector 400h (a bug) */
+	if (!(a1 <= 0x400))
+	{
+		/* Invalid sectors */
+		v0 = 0; pc0 = ra;
+		return;
+	}
 	card_active_chan = a0;
 	port = a0 >> 4;
 
@@ -2173,7 +2179,13 @@ void psxBios__card_read() { // 0x4f
 #ifdef PSXBIOS_LOG
 	PSXBIOS_LOG("psxBios_%s\n", biosB0n[0x4f]);
 #endif
-
+	/* Function also accepts sector 400h (a bug) */
+	if (!(a1 <= 0x400))
+	{
+		/* Invalid sectors */
+		v0 = 0; pc0 = ra;
+		return;
+	}
 	card_active_chan = a0;
 	port = a0 >> 4;