From 4902a1e07dc58ea121a54954a8c9cf523737d1a2 Mon Sep 17 00:00:00 2001
From: Abdessamad Derraz <3028866+Abdess@users.noreply.github.com>
Date: Fri, 16 Oct 2026 06:39:17 +0200
Subject: [PATCH] fix: check atari800 roms the way sysrom.c finds them

---
 emulators/atari800.yml       | 16 +++++++++-------
 tests/test_profile_checks.py | 21 +++++++++++++++++++++
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/emulators/atari800.yml b/emulators/atari800.yml
index 3c952027..dc8a0e85 100644
--- a/emulators/atari800.yml
+++ b/emulators/atari800.yml
@@ -40,7 +40,7 @@ files:
     size: 2048
     md5: 281f20ea4320404ec820fb7ec0693b38
     aliases: [atari5200.rom, atar5200.rom, 5200.bin, atari_5200.rom]
-    validation: [crc32]
+    validation: [size]
     note: >
       Atari 5200 BIOS (original). Mapped at $F800-$FFFF.
       Altirra 5200 OS is used when this file is absent.
@@ -60,7 +60,7 @@ files:
     size: 8192
     md5: 0bac0c6a50104045d902df4503a4c30b
     aliases: [ataribasic.rom, basic.rom, atari_basic.rom]
-    validation: [crc32]
+    validation: [size]
     note: >
       Atari BASIC Rev C. Required for 400/800 software that needs BASIC.
       Altirra BASIC is used as fallback. Enable via core option atari800_opt2.
@@ -78,7 +78,7 @@ files:
     size: 10240
     md5: eb1f32f5d9f382db1bbfb8d7f9cb343a
     aliases: [atari_osa.rom, atari_os_a.rom]
-    validation: [crc32]
+    validation: [size]
     note: >
       Atari 400/800 OS Rev A. Altirra OS 800 is used as fallback.
       Auto-select order: OS B NTSC, OS A NTSC, OS A PAL, custom, Altirra.
@@ -96,7 +96,7 @@ files:
     md5: 4177f386a3bac989a981d3fe3388cb6c
     crc32: 0e86d61d
     aliases: [atari_osb.rom, atari_os_b.rom]
-    validation: [crc32]
+    validation: [size]
     note: >
       Atari 400/800 OS Rev B (NTSC). CRC32 0x0e86d61d matches sysrom.c
       SYSROM_B_NTSC. Preferred over Rev A for 400/800 mode.
@@ -120,7 +120,7 @@ files:
     size: 16384
     md5: 06daac977823773a3eea3422fd26a703
     aliases: [atarixlxe.rom, atari_xlxe.rom, atari_xl_xe.rom]
-    validation: [crc32]
+    validation: [size]
     note: >
       Atari XL/XE OS. Used for 800XL, 130XE, and XEGS modes.
       Altirra XL OS is used as fallback.
@@ -136,7 +136,8 @@ files:
     hle_fallback: true
     size: 16384
     md5: b7a2a04677d34f069eeb643d5238bf86
-    validation: [crc32]
+    crc32: "1eaf4002"
+    validation: [size, crc32]
     note: >
       Atari XEGS OS Rev 4 (BB01R4). Preferred OS for XEGS machine mode.
     source_ref: "atari800/src/sysrom.c:100"
@@ -150,7 +151,8 @@ files:
     required: false
     size: 8192
     md5: d7eb37aec6960cba36bc500e0e5d00bc
-    validation: [crc32]
+    crc32: "bdca01fb"
+    validation: [size, crc32]
     note: >
       XEGS built-in Missile Command ROM. Only used in XEGS machine mode.
       No built-in replacement exists for this ROM.
diff --git a/tests/test_profile_checks.py b/tests/test_profile_checks.py
index 31239214..b74e3787 100644
--- a/tests/test_profile_checks.py
+++ b/tests/test_profile_checks.py
@@ -111,5 +111,26 @@ class BeetleGbaBios(_Probe):
                 self.assertFalse(self.accepts("beetle_gba", "gba_bios.bin", b"\0" * size))
 
 
+class Atari800SystemRoms(_Probe):
+    """SYSROM_FindInDir takes a file of an allowed length whose CRC32 is in
+    SYSROM_roms, else, by its lowercased name, any file of that length as a
+    custom ROM (atari800/src/sysrom.c:88-112, 281-315, 387-416 at 4e7fbc7).
+    BB01R4_OS.ROM and XEGAME.ROM are on no name list: only their CRC32 makes
+    them that ROM."""
+
+    def test_named_roms_need_only_the_length(self):
+        for name, size in (("ATARIOSA.ROM", 10240), ("ATARIOSB.ROM", 10240),
+                           ("ATARIXL.ROM", 16384), ("5200.rom", 2048),
+                           ("ATARIBAS.ROM", 8192)):
+            with self.subTest(name=name):
+                self.assertTrue(self.accepts("atari800", name, b"\1" * size))
+                self.assertFalse(self.accepts("atari800", name, b"\1" * (size + 1)))
+
+    def test_unlisted_names_need_their_crc(self):
+        for name, size in (("BB01R4_OS.ROM", 16384), ("XEGAME.ROM", 8192)):
+            with self.subTest(name=name):
+                self.assertFalse(self.accepts("atari800", name, b"\1" * size))
+
+
 if __name__ == "__main__":
     unittest.main()