Add Paravis return entry for legacy Ventoy

paravis/patch_ventoy_paravis_return.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+"""Add the "return to Paravis main menu" item to Ventoy's grub.cfg.
+
+The extra menu entry chainloads the Paravis boot menu:
+
+  * UEFI -> /efi/Paravis/Boot/grub2/grubx64.efi
+  * BIOS -> MBR of the Ventoy disk: chainloader (${vtoydev})+1
+
+Usage:
+    python3 patch_ventoy_paravis_return.py <path-to-grub/grub.cfg>
+
+The patched file is written back to grub.cfg and copied to grbp.cfg in the
+same directory. grbp.cfg is loaded by the UEFI build (grubx64_parv.efi) that
+the Paravis menu chainloads; the legacy core.img loads grub.cfg.
+"""
+
+import io
+import os
+import sys
+
+FUNC = '''function paravis_return {
+    if [ "$grub_platform" = "efi" ]; then
+        search --no-floppy --file --set=root /efi/Paravis/Boot/grub2/grub.cfg
+        if [ "$grub_cpu" = "x86_64" ]; then
+            chainloader /efi/Paravis/Boot/grub2/grubx64.efi
+        else
+            chainloader /EFI/Boot/bootia32.efi
+        fi
+    else
+        chainloader (${vtoydev})+1
+    fi
+    boot
+}
+'''
+
+MENU = '''menuentry "Возврат в главное меню Paravis Flash" --id="paravis_return" --class="vtoyret" {
+    paravis_return
+}
+
+set default="paravis_return"
+'''
+
+
+def main():
+    if len(sys.argv) != 2:
+        print(__doc__)
+        return 1
+
+    path = sys.argv[1]
+    text = io.open(path, encoding='utf-8', newline='').read()
+
+    if 'function paravis_return' in text:
+        print('already patched: ' + path)
+    else:
+        anchor = 'function ventoy_ext_menu {'
+        if text.count(anchor) != 1:
+            print('anchor not found or not unique: ' + anchor)
+            return 1
+        text = text.replace(anchor, FUNC + '\n' + anchor, 1)
+
+        anchor = '#special VTOY_DEFAULT_IMAGE process'
+        if text.count(anchor) != 1:
+            print('anchor not found or not unique: ' + anchor)
+            return 1
+        text = text.replace(anchor, MENU + '\n' + anchor, 1)
+
+        io.open(path, 'w', encoding='utf-8', newline='').write(text)
+        print('patched: ' + path)
+
+    grbp = os.path.join(os.path.dirname(path), 'grbp.cfg')
+    io.open(grbp, 'w', encoding='utf-8', newline='').write(text)
+    print('written: ' + grbp)
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())