diff --git a/emulators/openmsx.yml b/emulators/openmsx.yml
index b088e8cd3..c8f8d3913 100644
--- a/emulators/openmsx.yml
+++ b/emulators/openmsx.yml
@@ -1,5 +1,6 @@
 emulator: openMSX
 type: standalone
+core_classification: other
 source: "https://github.com/openMSX/openMSX"
 upstream: "https://github.com/openMSX/openMSX"
 profiled_date: "2026-03-26"
@@ -22,6 +23,11 @@ systems:
   - msxturbor
   - colecovision
   - spectravideo
+standalone_directories:
+  - "OPENMSX_HOME"
+  - "~/.openMSX"
+standalone_pools:
+  filepool: "share/systemroms"
 
 notes: |
   Standalone MSX emulator supporting MSX1 through turboR, ColecoVision,
@@ -35,13 +41,14 @@ notes: |
   looked up beside the machine's XML (src/memory/Rom.cc:121-170,
   src/config/HardwareConfig.cc:279-280, src/file/FileContext.cc:152-156).
   Files may be gzipped or individually zipped.
-  Each user data directory contributes share/systemroms, scanned
-  recursively (src/file/FilePool.cc:27, src/file/FilePoolCore.cc:369-385). RetroBat
-  sets OPENMSX_HOME to bios/openmsx and refuses to start a machine whose
-  ROMs are not in bios/openmsx/share/systemroms. RetroPie links
-  share/systemroms to BIOS/openmsx and Batocera adds bios/openmsx to the
-  pool, both scanned recursively, so openmsx/share/systemroms serves all
-  three.
+  The user directory is $OPENMSX_HOME, else ~/.openMSX, and its share/
+  subfolder is the user data directory unless $OPENMSX_USER_DATA names
+  another (src/file/FileOperations.cc:415-448). The pool starts with
+  systemroms below the user and the system data directories
+  (src/file/FilePool.cc:21-33), and each `filepool add -types system_rom`
+  entry is searched the same way, recursively, until a file of the SHA1 is
+  found (src/file/FilePool.cc:98-142, src/file/FilePoolCore.cc:244-264,
+  369-385).
 
   Batocera configgen (openmsxGenerator.py) configures filepool paths
   (/userdata/bios/Machines position 1, /userdata/bios/openmsx position 2)
@@ -67,7 +74,7 @@ files:
   # Based on Philips NMS 8245 with extra hardware
   # -------------------------------------------------------
   - name: NMS8245SystemROM1.08.bin
-    path: "openmsx/share/systemroms/NMS8245SystemROM1.08.bin"
+    path: "share/systemroms/NMS8245SystemROM1.08.bin"
     sha1: cc57c1dcd7249ea9f8e2547244592e7d97308ed0
     required: true
     size: 65536
@@ -76,7 +83,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2_EN.xml:24,65,111"
 
   - name: fmpac.rom
-    path: "openmsx/share/systemroms/fmpac.rom"
+    path: "share/systemroms/fmpac.rom"
     sha1: fec451b9256570a0e4869355a40329c57f40705f
     required: true
     description: "Panasonic SW-M004 FMPAC (FM-PAC) sound cartridge ROM"
@@ -84,7 +91,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2_EN.xml:83"
 
   - name: phc-70fd2_basickun.rom
-    path: "openmsx/share/systemroms/phc-70fd2_basickun.rom"
+    path: "share/systemroms/phc-70fd2_basickun.rom"
     sha1: 22b3191d865010264001b9d896186a9818478a6b
     required: true
     description: "Sanyo PHC-70FD2 MSX-BASIC Kun compiler ROM"
@@ -92,7 +99,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2_EN.xml:89, share/machines/Boosted_MSX2+_JP.xml:167, share/machines/Boosted_MSXturboR_with_IDE.xml:79"
 
   - name: yrw801.rom
-    path: "openmsx/share/systemroms/yrw801.rom"
+    path: "share/systemroms/yrw801.rom"
     sha1: 32760893ce06dbe3930627755ba065cc3d8ec6ca
     required: true
     description: "Yamaha YRW801 MoonSound wavetable ROM"
@@ -104,7 +111,7 @@ files:
   # Based on Panasonic FS-A1WSX with extra hardware
   # -------------------------------------------------------
   - name: fs-a1wsx_basic-bios2p.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_basic-bios2p.rom"
+    path: "share/systemroms/fs-a1wsx_basic-bios2p.rom"
     sha1: f4433752d3bf876bfefb363c749d4d2e08a218b6
     required: true
     description: "FS-A1WSX MSX2+ BIOS and BASIC ROM"
@@ -112,7 +119,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2+_JP.xml:143"
 
   - name: fs-a1wsx_fmbasic.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_fmbasic.rom"
+    path: "share/systemroms/fs-a1wsx_fmbasic.rom"
     sha1: aad42ba4289b33d8eed225d42cea930b7fc5c228
     required: true
     description: "FS-A1WSX MSX-MUSIC (OPLL) ROM"
@@ -121,7 +128,7 @@ files:
 
   - name: fs-a1wsx_msx2psub.rom
     installed_on: [retropie]
-    path: "openmsx/share/systemroms/fs-a1wsx_msx2psub.rom"
+    path: "share/systemroms/fs-a1wsx_msx2psub.rom"
     sha1: fe0254cbfc11405b79e7c86c7769bd6322b04995
     required: true
     description: "FS-A1WSX MSX2+ Sub ROM"
@@ -130,7 +137,7 @@ files:
     note: "RetroPie unpacks openmsxroms.tar.gz into the installed share/systemroms, which the file pool scans. This ROM is in it as MSX2PEXT.ROM and is found by its SHA1."
 
   - name: fs-a1wsx_kanjibasic.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_kanjibasic.rom"
+    path: "share/systemroms/fs-a1wsx_kanjibasic.rom"
     sha1: dcc3a67732aa01c4f2ee8d1ad886444a4dbafe06
     required: true
     description: "FS-A1WSX Kanji Driver with BASIC ROM"
@@ -138,7 +145,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2+_JP.xml:225"
 
   - name: fs-a1wsx_disk.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_disk.rom"
+    path: "share/systemroms/fs-a1wsx_disk.rom"
     sha1: 7ed7c55e0359737ac5e68d38cb6903f9e5d7c2b6
     required: true
     description: "FS-A1WSX FDC (TC8566AF) disk controller ROM"
@@ -146,7 +153,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2+_JP.xml:237"
 
   - name: fs-a1wsx_firmware.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_firmware.rom"
+    path: "share/systemroms/fs-a1wsx_firmware.rom"
     sha1: 3330d9b6b76e3c4ccb7cf252496ed15d08b95d3f
     required: true
     description: "FS-A1WSX Panasonic firmware ROM"
@@ -154,7 +161,7 @@ files:
     source_ref: "share/machines/Boosted_MSX2+_JP.xml:251"
 
   - name: fs-a1wsx_kanjifont.rom
-    path: "openmsx/share/systemroms/fs-a1wsx_kanjifont.rom"
+    path: "share/systemroms/fs-a1wsx_kanjifont.rom"
     sha1: 5aff2d9b6efc723bc395b0f96f0adfa83cc54a49
     aliases: [fs-a1gt_kanjifont.rom]
     required: true
@@ -168,7 +175,7 @@ files:
   # Based on Panasonic FS-A1GT with IDE interface
   # -------------------------------------------------------
   - name: fs-a1gt_firmware.rom
-    path: "openmsx/share/systemroms/fs-a1gt_firmware.rom"
+    path: "share/systemroms/fs-a1gt_firmware.rom"
     sha1:
       - e779c338eb91a7dea3ff75f3fde76b8af22c4a3a
       - 5fa3aa79aeba2c0441f349e78e9a16d9d64422ea
@@ -178,7 +185,7 @@ files:
     source_ref: "share/machines/Boosted_MSXturboR_with_IDE.xml:23"
 
   - name: ide250.dat
-    path: "openmsx/share/systemroms/ide250.dat"
+    path: "share/systemroms/ide250.dat"
     sha1: 93e41c7d479bc90c1d1f6d081af20fd9924b8ada
     required: true
     description: "Sunrise IDE 2.50 interface ROM"
@@ -186,7 +193,7 @@ files:
     source_ref: "share/machines/Boosted_MSXturboR_with_IDE.xml:49"
 
   - name: ide250.zip
-    path: "openmsx/share/systemroms/ide250.zip"
+    path: "share/systemroms/ide250.zip"
     required: false
     description: "Sunrise IDE 2.50 distribution archive (IDE250.DAT, IDE250.TXT, IDEFLOAD.COM, IDEFLOAD.TXT)"
     contents:
@@ -201,7 +208,7 @@ files:
   # ColecoVision with built-in Super Game Module
   # -------------------------------------------------------
   - name: COLECO.ROM
-    path: "openmsx/share/systemroms/COLECO.ROM"
+    path: "share/systemroms/COLECO.ROM"
     sha1: 45bedc4cbdeac66c7df59e9e599195c778d86a92
     required: true
     description: "ColecoVision system BIOS ROM"
@@ -212,7 +219,7 @@ files:
   # Spectravideo_SVI-328 (spectravideo)
   # -------------------------------------------------------
   - name: svi-3x8_v111.rom
-    path: "openmsx/share/systemroms/svi-3x8_v111.rom"
+    path: "share/systemroms/svi-3x8_v111.rom"
     sha1: 10349ce675f6d6d47f0976e39cb7188eba858d89
     required: true
     description: "SVI-328 BASIC v1.11 ROM"
@@ -224,7 +231,7 @@ files:
   # MSX1 with LaserDisc controller
   # -------------------------------------------------------
   - name: px-7_basic-bios1.rom
-    path: "openmsx/share/systemroms/px-7_basic-bios1.rom"
+    path: "share/systemroms/px-7_basic-bios1.rom"
     sha1: 302afb5d8be26c758309ca3df611ae69cced2821
     required: true
     description: "Pioneer PX-7 MSX1 BIOS and BASIC ROM"
@@ -232,7 +239,7 @@ files:
     source_ref: "share/machines/Pioneer_PX-7.xml:67"
 
   - name: px-7_pbasic.rom
-    path: "openmsx/share/systemroms/px-7_pbasic.rom"
+    path: "share/systemroms/px-7_pbasic.rom"
     sha1: 665d805f96616e1037f1823050657b7849899283
     required: true
     description: "Pioneer PX-7 LaserDisc PBASIC controller ROM"
@@ -248,7 +255,7 @@ files:
   # found does not start (src/memory/Rom.cc:173-184).
   # -------------------------------------------------------
   - name: cf-3300_basic-bios1.rom
-    path: "openmsx/share/systemroms/cf-3300_basic-bios1.rom"
+    path: "share/systemroms/cf-3300_basic-bios1.rom"
     sha1: c7a2c5baee6a9f0e1c6ee7d76944c0ab1886796c
     required: false
     size: 32768
@@ -257,7 +264,7 @@ files:
     source_ref: "share/machines/National_CF-3300.xml:51-52"
 
   - name: cf-3300_disk.rom
-    path: "openmsx/share/systemroms/cf-3300_disk.rom"
+    path: "share/systemroms/cf-3300_disk.rom"
     sha1: f1525de4e0b60a6687156c2a96f8a8b2044b6c56
     required: false
     size: 16384
@@ -266,7 +273,7 @@ files:
     source_ref: "share/machines/National_CF-3300.xml:75-76"
 
   - name: fs-5500_basic-bios2.rom
-    path: "openmsx/share/systemroms/fs-5500_basic-bios2.rom"
+    path: "share/systemroms/fs-5500_basic-bios2.rom"
     sha1: 44e0dd215b2a9f0770dd76fb49187c05b083eed9
     required: false
     size: 32768
@@ -275,7 +282,7 @@ files:
     source_ref: "share/machines/National_FS-5500F2.xml:76-77, share/machines/National_FS-5500F1.xml:78"
 
   - name: fs-5500_msx2sub.rom
-    path: "openmsx/share/systemroms/fs-5500_msx2sub.rom"
+    path: "share/systemroms/fs-5500_msx2sub.rom"
     sha1: 4be8371f3b03e70ddaca495958345f3c4f8e2d36
     required: false
     size: 16384
@@ -284,7 +291,7 @@ files:
     source_ref: "share/machines/National_FS-5500F2.xml:100-101, share/machines/National_FS-5500F1.xml:102"
 
   - name: fs-5500_kanjibasic.rom
-    path: "openmsx/share/systemroms/fs-5500_kanjibasic.rom"
+    path: "share/systemroms/fs-5500_kanjibasic.rom"
     sha1: 3a9a942ed888dd641cddf8deada1879c454df3c6
     required: false
     size: 32768
@@ -293,7 +300,7 @@ files:
     source_ref: "share/machines/National_FS-5500F2.xml:107-108, share/machines/National_FS-5500F1.xml:109"
 
   - name: fs-5500_kanjifont.rom
-    path: "openmsx/share/systemroms/fs-5500_kanjifont.rom"
+    path: "share/systemroms/fs-5500_kanjifont.rom"
     sha1: 9ed3ab6d893632b9246e91b412cd5db519e7586b
     required: false
     size: 131072
@@ -302,7 +309,7 @@ files:
     source_ref: "share/machines/National_FS-5500F2.xml:20-21, share/machines/National_FS-5500F1.xml:22"
 
   - name: fs-5500_superimp.rom
-    path: "openmsx/share/systemroms/fs-5500_superimp.rom"
+    path: "share/systemroms/fs-5500_superimp.rom"
     sha1: b677a861b67e8763a11d5dcf52416b42493ade57
     required: false
     size: 32768
@@ -311,7 +318,7 @@ files:
     source_ref: "share/machines/National_FS-5500F2.xml:117-118, share/machines/National_FS-5500F1.xml:119"
 
   - name: nms8245_msx2sub.rom
-    path: "openmsx/share/systemroms/nms8245_msx2sub.rom"
+    path: "share/systemroms/nms8245_msx2sub.rom"
     sha1:
       - 5c1f9c7fb655e43d38e5dd1fcc6b942b2ff68b02
       - e7905d16d2ccd57a013c122dc432106cd59ef52c
@@ -322,7 +329,7 @@ files:
     source_ref: "share/machines/Philips_NMS_8245.xml:108-110"
 
   - name: vg8020_basic-bios1.rom
-    path: "openmsx/share/systemroms/vg8020_basic-bios1.rom"
+    path: "share/systemroms/vg8020_basic-bios1.rom"
     sha1: 829c00c3114f25b3dae5157c0a238b52a3ac37db
     required: false
     size: 32768
@@ -331,7 +338,7 @@ files:
     source_ref: "share/machines/Philips_VG_8020.xml:53-54"
 
   - name: svi-738_basic-bios1.rom
-    path: "openmsx/share/systemroms/svi-738_basic-bios1.rom"
+    path: "share/systemroms/svi-738_basic-bios1.rom"
     sha1: c53b3f2c00f31683914f7452f3f4d94ae2929c0d
     required: false
     size: 32768
@@ -340,7 +347,7 @@ files:
     source_ref: "share/machines/Spectravideo_SVI-738.xml:53-54"
 
   - name: svi-738_se_basic-bios1.rom
-    path: "openmsx/share/systemroms/svi-738_se_basic-bios1.rom"
+    path: "share/systemroms/svi-738_se_basic-bios1.rom"
     sha1: 87f4d0fa58cfe9cef818a3185df2735e6da6168c
     required: false
     size: 32768
@@ -349,7 +356,7 @@ files:
     source_ref: "share/machines/Spectravideo_SVI-738_SE.xml:53-54"
 
   - name: svi-738_rs232.rom
-    path: "openmsx/share/systemroms/svi-738_rs232.rom"
+    path: "share/systemroms/svi-738_rs232.rom"
     sha1: 4e9384c9d137f0ab65ffc5a78f04cd8c9df6c8b7
     required: false
     size: 8192
@@ -358,7 +365,7 @@ files:
     source_ref: "share/machines/Spectravideo_SVI-738.xml:76-77, share/machines/Spectravideo_SVI-738_SE.xml:76-77"
 
   - name: svi-738_disk.rom
-    path: "openmsx/share/systemroms/svi-738_disk.rom"
+    path: "share/systemroms/svi-738_disk.rom"
     sha1:
       - 99a40266bc296cef1d432cb0caa8df1a7e570be4
       - 55d5d1fd57d35384b821af62083f2a23d85580e6
diff --git a/platforms/batocera.yml b/platforms/batocera.yml
index 0d55954da..95c94a27c 100644
--- a/platforms/batocera.yml
+++ b/platforms/batocera.yml
@@ -6562,6 +6562,24 @@ launchers:
   passes_to: environment FLYCAST_BIOS_PATH
   fails_when_missing: false
   source_ref: "package/batocera/core/batocera-configgen/configgen/configgen/generators/flycast/flycastGenerator.py:199"
+- emulator: openmsx
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: /userdata/bios/Machines
+  passes_to: "written: filepool add -path /userdata/bios/Machines -types system_rom\
+    \ -position 1"
+  fails_when_missing: false
+  source_ref: "package/batocera/core/batocera-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:88"
+- emulator: openmsx
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: /userdata/bios/openmsx
+  passes_to: "written: filepool add -path /userdata/bios/openmsx -types system_rom\
+    \ -position 2"
+  fails_when_missing: false
+  source_ref: "package/batocera/core/batocera-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:89"
 - emulator: o2em
   build: libretro
   kind: core_option
diff --git a/platforms/knulli.yml b/platforms/knulli.yml
index 3345c487d..e1c6ebafe 100644
--- a/platforms/knulli.yml
+++ b/platforms/knulli.yml
@@ -5685,6 +5685,24 @@ launchers:
   passes_to: environment FLYCAST_BIOS_PATH
   fails_when_missing: false
   source_ref: "package/system/knulli-configgen/configgen/configgen/generators/flycast/flycastGenerator.py:239"
+- emulator: openmsx
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: /userdata/bios/Machines
+  passes_to: "written: filepool add -path /userdata/bios/Machines -types system_rom\
+    \ -position 1"
+  fails_when_missing: false
+  source_ref: "package/system/knulli-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:95"
+- emulator: openmsx
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: /userdata/bios/openmsx
+  passes_to: "written: filepool add -path /userdata/bios/openmsx -types system_rom\
+    \ -position 2"
+  fails_when_missing: false
+  source_ref: "package/system/knulli-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:96"
 - emulator: lexaloffle
   build: standalone
   kind: fixed_name
@@ -6014,24 +6032,6 @@ launchers:
   passes_to: command line -crosshairpath
   fails_when_missing: false
   source_ref: "package/system/knulli-configgen/configgen/configgen/generators/mame/mameGenerator.py:180"
-- emulator: openmsx
-  build: standalone
-  kind: passes_path
-  names: []
-  search_dir: /userdata/bios/Machines
-  passes_to: "written: filepool add -path /userdata/bios/Machines -types system_rom\
-    \ -position 1"
-  fails_when_missing: false
-  source_ref: "package/system/knulli-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:95"
-- emulator: openmsx
-  build: standalone
-  kind: passes_path
-  names: []
-  search_dir: /userdata/bios/openmsx
-  passes_to: "written: filepool add -path /userdata/bios/openmsx -types system_rom\
-    \ -position 2"
-  fails_when_missing: false
-  source_ref: "package/system/knulli-configgen/configgen/configgen/generators/openmsx/openmsxGenerator.py:96"
 - emulator: fpinball
   build: standalone
   kind: passes_path
diff --git a/platforms/retrobat.yml b/platforms/retrobat.yml
index 5786bc1a0..540f55dea 100644
--- a/platforms/retrobat.yml
+++ b/platforms/retrobat.yml
@@ -4779,6 +4779,14 @@ launchers:
   fails_when_missing: ApplicationException '<machine> machine has missing BIOS file
     '<c>' in 'bios\openmsx\share\systemroms' folder.'
   source_ref: "emulatorLauncher/Generators/OpenMSX.Generator.cs:156-159, 467"
+- emulator: openmsx
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: bios/openmsx
+  passes_to: environment OPENMSX_HOME
+  fails_when_missing: false
+  source_ref: "emulatorLauncher/Generators/OpenMSX.Generator.cs:51, 255"
 - emulator: kronos
   build: standalone
   kind: fixed_name
diff --git a/platforms/retropie.yml b/platforms/retropie.yml
index cc54b45a2..34276c303 100644
--- a/platforms/retropie.yml
+++ b/platforms/retropie.yml
@@ -778,6 +778,15 @@ launchers:
   passes_to: $configdir/msx/openmsx/share/systemroms is a symlink to it
   fails_when_missing: false
   source_ref: "scriptmodules/emulators/openmsx.sh:77"
+- emulator: openmsx
+  package: openmsx
+  build: standalone
+  kind: links
+  names: []
+  search_dir: $configdir/msx/openmsx
+  passes_to: $home/.openMSX is a symlink to it
+  fails_when_missing: false
+  source_ref: "scriptmodules/emulators/openmsx.sh:76"
 - emulator: oricutron
   package: oricutron
   repo: "git https://github.com/HerbFargus/oricutron.git extras"
@@ -1269,6 +1278,15 @@ launchers:
   passes_to: $md_inst/share/xroar/roms is a symlink to it
   fails_when_missing: false
   source_ref: "scriptmodules/emulators/xroar.sh:52"
+- emulator: xroar
+  package: xroar
+  build: standalone
+  kind: passes_path
+  names: []
+  search_dir: $md_inst
+  passes_to: "${prefix} of configure --prefix"
+  fails_when_missing: false
+  source_ref: "scriptmodules/emulators/xroar.sh:37"
 - emulator: yabasanshiro
   package: yabasanshiro
   repo: "git https://github.com/retropie/yabause.git pi4-1-9-0"
diff --git a/scripts/scraper/batocera_launchers.py b/scripts/scraper/batocera_launchers.py
index 67f03887e..8f62babcf 100644
--- a/scripts/scraper/batocera_launchers.py
+++ b/scripts/scraper/batocera_launchers.py
@@ -15,7 +15,8 @@ launcher looks for nothing".
 from __future__ import annotations
 
 import ast
-from collections.abc import Callable
+import re
+from collections.abc import Callable, Iterable
 from typing import Any
 
 from .configgen_launchers import (
@@ -898,6 +899,56 @@ def environment_directories(cg: Configgen) -> list[Launcher]:
     return launchers
 
 
+# Generators that hand the emulator a /userdata/bios directory through its
+# configuration: a line written to the file it reads (openMSX's script.tcl
+# filepool entries) or a key saved to it.
+CONFIG_DIRECTORY_GENERATORS = ("openmsx.openmsxGenerator",)
+
+
+def config_directories(
+    cg: Configgen, modules: Iterable[str] = CONFIG_DIRECTORY_GENERATORS
+) -> list[Launcher]:
+    """file.write("<line naming a BIOS directory>") and settings.save(key, <BIOS directory>)."""
+    prefix = cg.bios.rstrip("/")
+    inside = re.compile(rf"{re.escape(prefix)}(?:/[^\s\"';]*)?")
+    launchers = []
+    for module in modules:
+        src = cg.generator(module)
+        constants = dict(cg.paths)
+        for node in src.tree.body:
+            name = _assigned_name(node)
+            value = _path_value(getattr(node, "value", None), constants)
+            if name is not None and value is not None:
+                constants[name] = value
+        found: list[tuple[str, str, ast.Call]] = []
+        for call in _calls(src.tree, attr="write"):
+            text = call.args[0] if len(call.args) == 1 else None
+            if isinstance(text, ast.Constant) and isinstance(text.value, str):
+                line = text.value.strip()
+                named = inside.search(line)
+                if named:
+                    found.append((named.group(0), f"written: {line}", call))
+        for call in _calls(src.tree, attr="save"):
+            if len(call.args) != 2 or not isinstance(call.args[0], ast.Constant):
+                continue
+            value = _path_value(call.args[1], constants)
+            if value is None and isinstance(call.args[1], ast.Constant):
+                value = str(call.args[1].value)
+            if value is not None and (value.rstrip("/") == prefix or value.startswith(prefix + "/")):
+                found.append((value, str(call.args[0].value), call))
+        if not found:
+            src.fail("hands no /userdata/bios directory through its config")
+        launchers.extend(
+            Launcher(
+                emulator=cg.emulator(module), build="standalone", kind="passes_path",
+                names=[], search_dir=directory, passes_to=passes_to,
+                source_ref=src.ref([src.span(call)]),
+            )
+            for directory, passes_to, call in found
+        )
+    return launchers
+
+
 # libretro core options whose value names the BIOS file the core opens.
 FILE_OPTIONS = (("_o2em_options", "o2em_bios"), ("_neocd_options", "neocd_bios"))
 
@@ -952,7 +1003,8 @@ def core_file_options(cg: Configgen) -> list[Launcher]:
 
 EXTRACTORS: tuple[Callable[[Configgen], list[Launcher]], ...] = (
     duckstation, duckstation_legacy, hatari, xemu, melonds, mupen64plus,
-    x16emu, gsplus, lexaloffle, environment_directories, core_file_options,
+    x16emu, gsplus, lexaloffle, environment_directories, config_directories,
+    core_file_options,
 )
 
 
diff --git a/scripts/scraper/knulli_launchers.py b/scripts/scraper/knulli_launchers.py
index 5a31bcd6b..4ea63895f 100644
--- a/scripts/scraper/knulli_launchers.py
+++ b/scripts/scraper/knulli_launchers.py
@@ -31,6 +31,7 @@ import yaml
 try:
     from .batocera_launchers import (
         Configgen,
+        config_directories,
         _path_value,
         _render,
         _system_branches,
@@ -53,6 +54,7 @@ try:
 except ImportError:
     from batocera_launchers import (  # type: ignore[no-redef]
         Configgen,
+        config_directories,
         _path_value,
         _render,
         _system_branches,
@@ -84,9 +86,18 @@ PICO8_INSTALLER = "board/fsoverlay/usr/bin/knulli-install-pico8"
 ES_FEATURES = "package/emulationstation/knulli-es-system/es_features.yml"
 
 # Batocera's extractors that read KNULLI's generators unchanged.
+# The generators of Batocera's config_directories that KNULLI keeps in the
+# same shape: openMSX's filepool lines.
+CONFIG_DIRECTORY_GENERATORS = ("openmsx.openmsxGenerator",)
+
+
+def knulli_config_directories(cg: Configgen) -> list[Launcher]:
+    return config_directories(cg, CONFIG_DIRECTORY_GENERATORS)
+
+
 SHARED = (
     duckstation, duckstation_legacy, hatari, xemu, melonds, mupen64plus, x16emu,
-    environment_directories,
+    environment_directories, knulli_config_directories,
 )
 
 
@@ -365,7 +376,6 @@ GENERIC_SITES = (
     GenericSites("amiberry/amiberryGenerator.py", "passes_path"),
     GenericSites("fsuae/fsuaeGenerator.py", "passes_path"),
     GenericSites("mame/mameGenerator.py", "passes_path"),
-    GenericSites("openmsx/openmsxGenerator.py", "passes_path"),
     GenericSites("fpinball/fpinballGenerator.py", "passes_path"),
     GenericSites(
         "libretro/libretroRetroarchCustom.py", "passes_path", "libretro", emulator="retroarch"
diff --git a/scripts/scraper/retrobat_launchers.py b/scripts/scraper/retrobat_launchers.py
index 6c851eade..b15ea4f3d 100644
--- a/scripts/scraper/retrobat_launchers.py
+++ b/scripts/scraper/retrobat_launchers.py
@@ -1279,6 +1279,29 @@ def openmsx(sources: dict[str, Source]) -> list[Record]:
         )
     if not records:
         raise LauncherPatternMissing(src.path, "biosFiles entries")
+    # OPENMSX_HOME is the user directory: openMSX reads share/systemroms below it.
+    home = src.find(
+        rf'string (\w+) = Path\.Combine\({BIOS}, "([^"]+)"\);', "OPENMSX_HOME folder"
+    )
+    handed = src.find(
+        rf'ret\.EnvironmentVariables\["(OPENMSX_HOME)"\] = {home.group(1)};',
+        "OPENMSX_HOME environment", home.end(),
+    )
+    records.append(
+        _record(
+            "openmsx",
+            "standalone",
+            "passes_path",
+            [],
+            source_ref(
+                (src.path, [src.lines(home.start(), home.end()),
+                            src.lines(handed.start(), handed.end())])
+            ),
+            search_dir=f"bios/{home.group(2)}",
+            passes_to=f"environment {handed.group(1)}",
+            fails_when_missing=False,
+        )
+    )
     return records
 
 
diff --git a/scripts/scraper/retropie_launchers.py b/scripts/scraper/retropie_launchers.py
index 65c03d28d..6a488b935 100644
--- a/scripts/scraper/retropie_launchers.py
+++ b/scripts/scraper/retropie_launchers.py
@@ -525,6 +525,7 @@ class PackageReader:
             self._links(links)
         self._outside_bios(events)
         self._working_directory(events)
+        self._reaching_links(events)
         return self.records
 
     @staticmethod
@@ -828,6 +829,54 @@ class PackageReader:
             )
 
 
+    def _reaching_links(self, events: list[Event]) -> None:
+        """The directories outside the BIOS one that a whole-directory link lies in.
+
+        openmsx's moveConfigDir "$home/.openMSX" "$configdir/msx/openmsx"
+        puts the emulator's directory where the systemroms link to BIOS/openmsx
+        lies, and xroar's ./configure --prefix="$md_inst" builds the program
+        whose share/xroar/roms links to $biosdir. Neither line names the BIOS
+        directory, and each says where the link is read from.
+        """
+        suffix = " is a symlink to it"
+        linked = [
+            record.passes_to.removesuffix(suffix).rstrip("/")
+            for record in self.records
+            if record.kind == "links" and not record.names
+            and (record.passes_to or "").endswith(suffix)
+        ]
+        if not linked:
+            return
+
+        def holds(directory: str) -> bool:
+            directory = directory.strip("\"'").rstrip("/")
+            return bool(directory) and any(
+                path == directory or path.startswith(directory + "/") for path in linked
+            )
+
+        for event in events:
+            if event.heredoc or not event.words or _mentions_bios(event.raw):
+                continue
+            command = event.words[0][0]
+            if command == "moveConfigDir" and len(event.words) >= 3:
+                link, real = event.words[1][0], event.words[2][0]
+                if holds(real):
+                    self.record(
+                        "links", [], [(event.path, event.line)],
+                        search_dir=real, passes_to=f"{link}{suffix}",
+                        fails_when_missing=False, depends_on_option=self._depends(event),
+                    )
+            elif command.endswith("configure"):
+                for word in event.words[1:]:
+                    prefix = word[0].strip("\"'")
+                    if prefix.startswith("--prefix=") and holds(prefix[len("--prefix="):]):
+                        self.record(
+                            "passes_path", [], [(event.path, event.line)],
+                            search_dir=prefix[len("--prefix="):].strip("\"'"),
+                            passes_to="${prefix} of configure --prefix",
+                            fails_when_missing=False, depends_on_option=self._depends(event),
+                        )
+
     def _working_directory(self, events: list[Event]) -> None:
         """The folder a generated launch script enters before it runs the emulator."""
         if self.package.id not in WORKING_DIRECTORY:
diff --git a/tests/test_launchers.py b/tests/test_launchers.py
index 838704d04..59cb86c6b 100644
--- a/tests/test_launchers.py
+++ b/tests/test_launchers.py
@@ -29,6 +29,7 @@ from scraper.batocera_launchers import (  # noqa: E402
     Configgen,
     Launcher,
     LauncherShapeError,
+    config_directories,
     duckstation,
     extract_launchers,
     hatari,
@@ -521,6 +522,49 @@ class LexaloffleBinaries(unittest.TestCase):
             lexaloffle(lexaloffle_tree(text))
 
 
+OPENMSX = f"{GENERATORS}/openmsx/openmsxGenerator.py"
+OPENMSX_FILEPOOL = '''    def generate(self, system, rom):
+        with settings_tcl.open("a") as file:
+            file.write("filepool add -path /userdata/bios/Machines -types system_rom -position 1\\n")
+            file.write("filepool add -path /userdata/bios/openmsx -types system_rom -position 2\\n")'''
+
+
+class ConfigDirectories(unittest.TestCase):
+    """A BIOS directory written into the emulator's config, at batocera-43.1."""
+
+    def test_each_filepool_line_hands_its_directory(self):
+        cg = configgen({OPENMSX: placed({1: "class OpenmsxGenerator:", 86: OPENMSX_FILEPOOL})})
+        records = [r.entry() for r in config_directories(cg, ("openmsx.openmsxGenerator",))]
+        self.assertEqual(
+            [(r["emulator"], r["kind"], r["search_dir"], r["source_ref"]) for r in records],
+            [
+                ("openmsx", "passes_path", "/userdata/bios/Machines", f"{OPENMSX}:88"),
+                ("openmsx", "passes_path", "/userdata/bios/openmsx", f"{OPENMSX}:89"),
+            ],
+        )
+        self.assertEqual(
+            records[1]["passes_to"],
+            "written: filepool add -path /userdata/bios/openmsx -types system_rom -position 2",
+        )
+
+    def test_a_saved_setting_hands_its_directory(self):
+        amiberry = f"{GENERATORS}/amiberry/amiberryGenerator.py"
+        text = placed({
+            1: "from pathlib import Path\n_BIOS_DIR = Path('/userdata/bios/amiga')",
+            10: "def generate():\n    amiberryconf.save('rom_path', _BIOS_DIR)",
+        })
+        (record,) = config_directories(configgen({amiberry: text}), ("amiberry.amiberryGenerator",))
+        self.assertEqual(
+            (record.search_dir, record.passes_to, record.source_ref),
+            ("/userdata/bios/amiga", "rom_path", f"{amiberry}:11"),
+        )
+
+    def test_a_generator_handing_no_bios_directory_raises(self):
+        cg = configgen({OPENMSX: "def generate():\n    file.write('savestate x')\n"})
+        with self.assertRaises(LauncherShapeError):
+            config_directories(cg, ("openmsx.openmsxGenerator",))
+
+
 class ExtractionNeverEmpty(unittest.TestCase):
     def test_a_generator_of_unknown_shape_stops_the_whole_scrape(self):
         find = DUCKSTATION_FIND.replace("def find_bios(", "def locate_bios(")
diff --git a/tests/test_launchers_retrobat.py b/tests/test_launchers_retrobat.py
index 30b523bc3..5cd4a0ec9 100644
--- a/tests/test_launchers_retrobat.py
+++ b/tests/test_launchers_retrobat.py
@@ -145,6 +145,9 @@ OPENMSX = """
         { "Philips_VG_8020", new string[] { "vg8020_basic-bios1.rom" } },
         { "Pioneer_PX-7", new string[] { "px-7_basic-bios1.rom", "px-7_pbasic.rom" } }
     };
+
+    string sharePath = Path.Combine(AppConfig.GetFullPath("bios"), "openmsx");
+    ret.EnvironmentVariables["OPENMSX_HOME"] = sharePath;
 """
 
 DUCKSTATION = """
@@ -390,12 +393,21 @@ class NamesInLauncherOrder(unittest.TestCase):
             [
                 ("-machine Philips_VG_8020", ["vg8020_basic-bios1.rom"]),
                 ("-machine Pioneer_PX-7", ["px-7_basic-bios1.rom", "px-7_pbasic.rom"]),
+                ("environment OPENMSX_HOME", []),
             ],
         )
         self.assertEqual(records[0]["search_dir"], "bios/openmsx/share/systemroms")
         self.assertFalse(records[0]["case_insensitive"])
         self.assertEqual(records[1]["source_ref"], f"{G}/OpenMSX.Generator.cs:1-4, 10")
 
+    def test_openmsx_home_is_handed_as_a_directory(self):
+        # OPENMSX_HOME is the user directory openMSX reads share/systemroms below.
+        records = rl.openmsx(_sources(**{f"{G}/OpenMSX.Generator.cs": OPENMSX}))
+        home = records[-1]
+        self.assertEqual(home["kind"], "passes_path")
+        self.assertEqual(home["search_dir"], "bios/openmsx")
+        self.assertEqual(home["source_ref"], f"{G}/OpenMSX.Generator.cs:13-14")
+
     def test_duckstation_reads_the_standalone_feature_not_the_core(self):
         search, option = rl.duckstation(
             _sources(**{f"{G}/Duckstation.Generator.cs": DUCKSTATION, rl.FEATURES: FEATURES})
diff --git a/tests/test_launchers_retropie.py b/tests/test_launchers_retropie.py
index 510aeaae7..b57cc60b8 100644
--- a/tests/test_launchers_retropie.py
+++ b/tests/test_launchers_retropie.py
@@ -315,6 +315,59 @@ UAE4ALL = module("uae4all", """
 """, 60)
 
 
+OPENMSX = module("openmsx", """
+    function configure_openmsx() {
+        mkUserDir "$home/.openMSX/share/systemroms"
+        moveConfigDir "$home/.openMSX" "$configdir/msx/openmsx"
+        moveConfigDir "$configdir/msx/openmsx/share/systemroms" "$home/RetroPie/BIOS/openmsx"
+        moveConfigDir "$home/.unrelated" "$configdir/msx/other"
+    }
+""", 74)
+
+
+XROAR = module("xroar", """
+    function build_xroar() {
+        ./configure --prefix="$md_inst" "${params[@]}"
+    }
+
+    function configure_xroar() {
+        mkdir -p "$md_inst/share/xroar"
+        ln -snf "$biosdir" "$md_inst/share/xroar/roms"
+    }
+""", 36)
+
+
+class ReachingLinks(unittest.TestCase):
+    """The directory outside BIOS that a whole-directory link is read from."""
+
+    def test_openmsx_user_directory_holds_the_systemroms_link(self):
+        found = records({f"{EMULATORS}/openmsx.sh": OPENMSX}, "openmsx")
+        links = [r for r in found if r["kind"] == "links"]
+        self.assertEqual(
+            [(r["search_dir"], r["passes_to"], r["source_ref"]) for r in links],
+            [
+                (
+                    "$home/RetroPie/BIOS/openmsx",
+                    "$configdir/msx/openmsx/share/systemroms is a symlink to it",
+                    f"{EMULATORS}/openmsx.sh:77",
+                ),
+                (
+                    "$configdir/msx/openmsx",
+                    "$home/.openMSX is a symlink to it",
+                    f"{EMULATORS}/openmsx.sh:76",
+                ),
+            ],
+        )
+
+    def test_xroar_install_prefix_holds_the_roms_link(self):
+        found = records({f"{EMULATORS}/xroar.sh": XROAR}, "xroar")
+        prefix = [r for r in found if r["kind"] == "passes_path"]
+        self.assertEqual(
+            [(r["search_dir"], r["passes_to"], r["source_ref"]) for r in prefix],
+            [("$md_inst", "${prefix} of configure --prefix", f"{EMULATORS}/xroar.sh:37")],
+        )
+
+
 class WorkingDirectory(unittest.TestCase):
     def test_drastic_reads_below_the_folder_its_script_enters(self):
         found = records({f"{EMULATORS}/drastic.sh": DRASTIC}, "drastic")
diff --git a/tests/test_standalone_links.py b/tests/test_standalone_links.py
index ad83765cd..e0e4a9728 100644
--- a/tests/test_standalone_links.py
+++ b/tests/test_standalone_links.py
@@ -497,3 +497,43 @@ class Scrapers(unittest.TestCase):
 if __name__ == "__main__":
     unittest.main()
 
+
+class OpenmsxOnEachPlatform(unittest.TestCase):
+    """openMSX finds system ROMs by SHA1 in share/systemroms below its user
+    directory and in every filepool entry. RetroBat sets OPENMSX_HOME to
+    bios/openmsx, RetroPie links share/systemroms of its user directory to
+    BIOS/openmsx, Batocera and KNULLI add bios/Machines and bios/openmsx to
+    the filepool and list their own files in bios/openmsx."""
+
+    EXPECTED = {
+        "batocera": {"share/systemroms": ("", "openmsx")},
+        "knulli": {"share/systemroms": ("", "openmsx")},
+        "retrobat": {"": ("", "openmsx")},
+        "retropie": {"share/systemroms": ("", "openmsx")},
+    }
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        cls.profile = load_emulator_profiles(str(REPO_ROOT / "emulators"))["openmsx"]
+
+    def test_each_platform_hands_openmsx_its_folder(self) -> None:
+        for platform, expected in self.EXPECTED.items():
+            with self.subTest(platform=platform):
+                cfg = load_platform_config(platform, str(REPO_ROOT / "platforms"))
+                self.assertEqual(
+                    standalone_bindings_for("openmsx", self.profile, standalone_set(cfg)),
+                    expected,
+                )
+
+    def test_every_system_rom_lands_in_bios_openmsx(self) -> None:
+        for platform in self.EXPECTED:
+            with self.subTest(platform=platform):
+                cfg = load_platform_config(platform, str(REPO_ROOT / "platforms"))
+                (view, _standalone), = platform_layouts(
+                    "openmsx", self.profile, standalone_set(cfg)
+                )
+                for entry in view["files"]:
+                    self.assertNotIn("unplaced", entry)
+                    self.assertTrue(
+                        entry["standalone_path"].startswith("openmsx/"), entry["standalone_path"]
+                    )