Update beetle_psx.md, beetle_psx_hw.md, and pcsx_rearmed.md: Added a How to obtain OpenBIOS section

docs/library/beetle_psx.md

@@ -45,6 +45,14 @@ As a replacement for any of the BIOS files mentioned above, it is also possible
 The `PSXONPSP660.bin` BIOS comes from the PSP, the `ps1_rom.bin` BIOS comes from the PS3, and the `openbios.bin` BIOS comes from PCSX-Redux; all are region-free.
 For Beetle PSX to recognize these BIOS files, you need to enable the "Override BIOS" option.
 
+### How to obtain a standalone OpenBIOS file
+
+If you wish to use a specific or updated standalone version of OpenBIOS (openbios.bin) rather than the built-in fallback:
+* As noted on https://github.com/grumpycoders/pcsx-redux, the latest AppImage is available at https://distrib.app/pub/org/pcsx-redux/project/dev-linux-x64.
+* Extract the Appimage: `./PCSX-Redux-HEAD-x86_64.AppImage --appimage-extract`
+* Copy the `openbios.bin` file from the generated `squashfs-root/usr/share/pcsx-redux/resources` directory.
+* Place `openbios.bin` in your RetroArch System/BIOS directory.
+
 ## Extensions
 
 Content that can be loaded by the Beetle PSX core have the following file extensions:

docs/library/beetle_psx_hw.md

@@ -48,6 +48,14 @@ As a replacement for any of the BIOS files mentioned above, it is also possible
 The `PSXONPSP660.bin` BIOS comes from the PSP, the `ps1_rom.bin` BIOS comes from the PS3, and the `openbios.bin` BIOS comes from PCSX-Redux; all are region-free.
 For Beetle PSX HW to recognize these BIOS files, you need to enable the "Override BIOS" option.
 
+### How to obtain a standalone OpenBIOS file
+
+If you wish to use a specific or updated standalone version of OpenBIOS (openbios.bin) rather than the built-in fallback:
+* As noted on https://github.com/grumpycoders/pcsx-redux, the latest AppImage is available at https://distrib.app/pub/org/pcsx-redux/project/dev-linux-x64.
+* Extract the Appimage: `./PCSX-Redux-HEAD-x86_64.AppImage --appimage-extract`
+* Copy the `openbios.bin` file from the generated `squashfs-root/usr/share/pcsx-redux/resources` directory.
+* Place `openbios.bin` in your RetroArch System/BIOS directory.
+
 ## Extensions
 
 Content that can be loaded by the Beetle PSX HW core have the following file extensions:

docs/library/pcsx_rearmed.md

@@ -45,6 +45,14 @@ If none of the above is found, PCSX_ReARMed will search for filenames starting w
 It doesn't seem to matter whatever BIOS version is used and from what region, as long as it's from a retail PSX/PS one.
 If no compatible BIOS is found, PCSX_ReARMed will revert to use the HLE BIOS, which can have compatibility issues (e.g. memory card issues in Suikoden games, some games just going into black screens, ...).
 
+### How to obtain the OpenBIOS file
+
+Unlike the other PlayStation cores (such as Beetle PSX, Beetle PSX HW, and SwanStation), PCSX ReARMed does not include OpenBIOS built-in. Instead, it features High-Level Emulation (HLE) BIOS, eliminating the need for an official BIOS file for most games. However, if you still want to use OpenBIOS (openbios.bin) with it:
+* As noted on https://github.com/grumpycoders/pcsx-redux, the latest AppImage is available at https://distrib.app/pub/org/pcsx-redux/project/dev-linux-x64.
+* Extract the Appimage: `./PCSX-Redux-HEAD-x86_64.AppImage --appimage-extract`
+* Copy the `openbios.bin` file from the generated `squashfs-root/usr/share/pcsx-redux/resources` directory.
+* Place `openbios.bin` in your RetroArch System/BIOS directory.
+
 ## Extensions
 
 Content that can be loaded by the PCSX ReARMed core have the following file extensions: