Fixes from brltty trunk:
- Use the correct environment variable names in the generated part of
  the udev rules file.
- Add command line flag to exclude devices that are generic (e.g.
  usb->serial chips that don't have specific vendor/product IDs)
--- a/updusbdevs
+++ b/updusbdevs
@@ -319,14 +319,19 @@
    return "<!-- $comment -->"
 }
 
-proc makeLines_android {vendor product drivers descriptions} {
+proc makeLines_android {vendor product drivers descriptions exclude} {
    set lines [list]
 
    foreach description $descriptions {
       lappend lines [makeComment_android $description]
    }
 
-   lappend lines "<usb-device vendor-id=\"$vendor\" product-id=\"$product\" />"
+   set line "<usb-device vendor-id=\"$vendor\" product-id=\"$product\" />"
+   if {$exclude} {
+      set line [makeComment_android $line]
+   }
+   lappend lines $line
+
    return $lines
 }
 
@@ -334,14 +339,19 @@
    return "# $comment"
 }
 
-proc makeLines_hotplug {vendor product drivers descriptions} {
+proc makeLines_hotplug {vendor product drivers descriptions exclude} {
    set lines [list]
 
    foreach description $descriptions {
       lappend lines [makeComment_hotplug $description]
    }
 
-   lappend lines [format "brltty-%s 0x%04x 0x%04x 0x%04x" [join $drivers ","] 3 $vendor $product]
+   set line [format "brltty-%s 0x%04x 0x%04x 0x%04x" [join $drivers ","] 3 $vendor $product]
+   if {$exclude} {
+      set line [makeComment_hotplug $line]
+   }
+   lappend lines $line
+
    return $lines
 }
 
@@ -349,14 +359,19 @@
    return "# $comment"
 }
 
-proc makeLines_udev {vendor product drivers descriptions} {
+proc makeLines_udev {vendor product drivers descriptions exclude} {
    set lines [list]
 
    foreach description $descriptions {
       lappend lines [makeComment_udev $description]
    }
 
-   lappend lines [format "ENV\{PRODUCT\}==\"%x/%x/*\", ENV\{BRLTTY_DRIVER\}=\"%s\", GOTO=\"brltty_usb_run\"" $vendor $product [join $drivers ","]]
+   set line [format "ENV\{PRODUCT\}==\"%x/%x/*\", ENV\{BRLTTY_BRAILLE_DRIVER\}=\"%s\", GOTO=\"brltty_usb_run\"" $vendor $product [join $drivers ","]]
+   if {$exclude} {
+      set line [makeComment_udev $line]
+   }
+   lappend lines $line
+
    return $lines
 }
 
@@ -364,14 +379,21 @@
    return "; $comment"
 }
 
-proc makeLines_windows {vendor product drivers descriptions} {
+proc makeLines_windows {vendor product drivers descriptions exclude} {
    set lines [list]
-   lappend lines [format "\"\$1: %s\"=LIBUSB_DEV, USB\\VID_%04X&PID_%04X" [join $descriptions ", "] $vendor $product]
+   set line [format "\"\$1: %s\"=LIBUSB_DEV, USB\\VID_%04X&PID_%04X" [join $descriptions ", "] $vendor $product]
+
+   if {$exclude} {
+      set line [makeComment_windows $line]
+   }
+
+   lappend lines $line
    return $lines
 }
 
 proc makeLines {linesArray schemes deviceTable} {
    global genericDevices
+   upvar #0 optionValues(nogeneric) excludeGenericDevices
 
    foreach scheme $schemes {
       set makeLines makeLines_$scheme
@@ -400,6 +422,8 @@
                lappend descriptions "[dict get $deviceEntry name] \[[dict get $deviceEntry model]\]"
             }
 
+            set exclude 0
+
             if {[dict get $productEntry generic]} {
                lappend lines [$makeComment "Generic Identifier"]
                set generic [dict get $genericDevices $identifier]
@@ -412,9 +436,11 @@
                      lappend lines [$makeComment "$header: [dict get $generic $property]"]
                   }
                }
+
+               set exclude $excludeGenericDevices
             }
 
-            eval [list lappend lines] [$makeLines $vendor $product [lsort -unique $codes] [lsort $descriptions]]
+            eval [list lappend lines] [$makeLines $vendor $product [lsort -unique $codes] [lsort $descriptions] $exclude]
             lappend lines ""
          }
       }
@@ -598,9 +624,10 @@
 }]
 
 set optionDefinitions {
-   {quiet   counter}
-   {verbose counter}
-   {test    flag}
+   {quiet     counter}
+   {verbose   counter}
+   {test      flag}
+   {nogeneric flag}
 }
 
 if {![processOptions optionValues argv $optionDefinitions]} {