[Asus  Eee Pad Transformer Prime] chrisfu:
I've got my tablet working again. Wifi, seemingly everything. I should have looked a tad harder before I wrote it off, because when I spent more than two minutes looking at things, the issue was clear.

Basically, when you use a busybox installer on it, it links certain commands in /system/xbin and /system/bin to a different toolbox binary. In this tablets case, commands like mount, df, dd, ps, kill etc were pointing to /data/local/toolbox. This didn't exist after the factory reset.

Luckily, /system/bin/busybox and /system/xbin/busybox were there with suid root permissions. Using '/system/xbin/busybox ls -l /system/bin' identified a handful of symbolic links that were pointing to non-existent files, highlighted in red. Easy.

1) /system/bin/busybox mount -o ro,remount /system

2) cd /system/bin

3) /system/bin/busybox ls -l /system/bin

4) Repeat the following two commands for every link that points to a dead (red) file. This example is for the "ps" command:

/system/bin/toolbox rm ps

/system/bin/toolbox ln -s toolbox ps

5) At the end, when you do a /system/bin/busybox ls -l /system/bin, you should see all the link targets green with no red ones.

Basically, your su binaries should still be there, as should your busybox binaries. All that's needed is a bit of fixing up from the mess your busybox installer made. My /system/bin now looks as though busybox was never installed.

@android:/system/bin # busybox ls -l
total 6692
-rwxr-xr-x 1 0 2000 96360 Sep 28 15:03 adb
-rwxr-xr-x 1 0 2000 191 Dec 23 2011 am
-rwxr-xr-x 1 0 2000 9500 Sep 28 15:03 app_process
-rwxr-xr-x 1 0 2000 49452 Sep 28 15:03 applypatch
-rwxr-xr-x 1 0 2000 9508 Aug 1 2008 atrace
-rwxr-xr-x 1 0 2000 5108 Sep 28 15:03 bluetoothd
-rwxr-xr-x 1 0 2000 199 Dec 23 2011 bmgr
-rwxr-xr-x 1 0 2000 21788 Sep 28 15:03 bootanimation
-rwxr-xr-x 1 0 2000 14004 Sep 28 15:03 brcm_patchram_plus
-rwxr-xr-x 1 0 2000 1747 Aug 1 2008 bt_firmware_loader.sh
-rwxr-xr-x 1 0 2000 156 Aug 1 2008 bu
-rwxr-xr-x 1 0 2000 954 Aug 1 2008 bugmailer.sh
-rwxr-xr-x 1 0 2000 5352 Sep 28 15:03 bugreport
-rwxr-xr-x 1 0 2000 5352 Aug 1 2008 camera_fw_check
lrwxrwxrwx 1 0 0 7 Sep 29 19:52 cat -> toolbox
-rwxr-xr-x 1 0 2000 587981 Aug 1 2008 chat
lrwxrwxrwx 1 0 0 7 Sep 29 19:52 chmod -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 chown -> toolbox
-rwxr-xr-x 1 0 2000 37 Dec 23 2011 cluster
-rwxr-xr-x 1 0 2000 44 Dec 23 2011 cluster_get.sh
-rwxr-xr-x 1 0 2000 50 Dec 23 2011 cluster_set.sh
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 cmp -> toolbox
-rwxr-xr-x 1 0 2000 207 Aug 1 2008 content
-rwxr-xr-x 1 0 2000 5352 Sep 28 15:03 dalvikvm
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 date -> toolbox
-rwxr-xr-x 1 0 2000 132440 Sep 28 15:03 dbus-daemon
-rwxr-xr-x 1 0 2000 43 Dec 23 2011 dcc
lrwxrwxrwx 1 0 0 7 Sep 29 19:53 dd -> toolbox
-rwxr-xr-x 1 0 2000 21736 Sep 28 15:03 debuggerd
-rwxr-xr-x 1 0 2000 9396 Sep 28 15:03 dexopt
lrwxrwxrwx 1 0 0 7 Sep 29 19:53 df -> toolbox
-rwxr-xr-x 1 0 2000 58788 Sep 28 15:03 dhcpcd
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 dmesg -> toolbox
-rwxr-xr-x 1 0 2000 105816 Sep 28 15:03 dnsmasq
-rwxr-xr-x 1 0 2000 26060 Sep 28 15:03 downloader
-rwxr-xr-x 1 0 2000 50460 Sep 28 15:03 drmserver
-rwxr-xr-x 1 0 2000 38184 Sep 28 15:03 dumpstate
-rwxr-xr-x 1 0 2000 9448 Sep 28 15:03 dumpsys
-rwxr-xr-x 1 0 2000 122500 Aug 1 2008 e2fsck
-rwxr-xr-x 1 0 2000 26148 Sep 28 15:03 fsck_msdos
-rwxr-xr-x 1 0 2000 605137 Sep 28 15:03 fu
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 getevent -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 getprop -> toolbox
-rwxr-xr-x 1 0 2000 1154080 Sep 28 15:03 glgps
-rwxr-xr-x 1 0 2000 9448 Sep 28 15:03 gzip
-rwxr-xr-x 1 0 2000 27176 Sep 28 15:03 hciattach
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 hd -> toolbox
-rwxr-xr-x 1 0 2000 10024 Sep 28 15:03 hdcp_test
-rwxr-xr-x 1 0 2000 272688 Sep 28 15:03 hostapd
-rwxr-xr-x 1 0 2000 64 Dec 23 2011 hotplug
lrwxrwxrwx 1 0 0 7 Sep 29 19:53 id -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 ifconfig -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 iftop -> toolbox
-rwxr-xr-x 1 0 2000 194 Dec 23 2011 ime
-rwxr-xr-x 1 0 2000 201 Dec 23 2011 input
lrwxrwxrwx 1 0 0 7 Sep 29 19:53 insmod -> toolbox
-rwxr-xr-x 1 0 2000 22012 Sep 28 15:03 installd
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 ioctl -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 ionice -> toolbox
-rwxr-xr-x 1 0 2000 136672 Sep 28 15:03 ip
-rwxr-xr-x 1 0 2000 187372 Sep 28 15:03 ip6tables
-rwxr-xr-x 1 0 2000 196260 Sep 28 15:03 iptables
-rwxr-xr-x 1 0 2000 13596 Sep 28 15:03 isp_fw_update
-rwxr-xr-x 1 0 2000 14232 Sep 28 15:03 keystore
lrwxrwxrwx 1 0 0 7 Sep 29 19:54 kill -> toolbox
-rwxr-xr-x 1 0 2000 79908 Sep 28 15:03 linker
lrwxrwxrwx 1 0 0 7 Sep 29 19:54 ln -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 log -> toolbox
-rwxr-xr-x 1 0 2000 13600 Sep 28 15:03 logcat
-rwxr-xr-x 1 0 2000 9516 Sep 28 15:03 logwrapper
lrwxrwxrwx 1 0 0 7 Sep 29 19:54 ls -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 lsmod -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 lsof -> toolbox
-rwxr-xr-x 1 0 2000 10436 Sep 28 15:03 make_ext4fs
lrwxrwxrwx 1 0 0 7 Sep 28 15:10 md5 -> toolbox
-rwxr-xr-x 1 0 2000 259452 Aug 1 2008 mdnsd
-rwxr-xr-x 1 0 2000 5300 Sep 28 15:03 mediaserver
lrwxrwxrwx 1 0 0 7 Sep 29 19:54 mkdir -> toolbox
-rwxr-xr-x 1 0 2000 153344 Sep 28 15:03 mksh
-rwxr-xr-x 1 0 2000 217 Dec 23 2011 monkey
lrwxrwxrwx 1 0 0 7 Sep 29 19:54 mount -> toolbox
-rwxr-xr-x 1 0 2000 60 Dec 23 2011 mount_debugfs.sh
-rwxr-xr-x 1 0 2000 17856 Sep 28 15:03 mtpd
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 mv -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 nandread -> toolbox
-rwxr-xr-x 1 0 2000 5304 Sep 28 15:03 ndc
-rwxr-s--- 1 0 3003 5484 Sep 28 15:03 netcfg
-rwxr-xr-x 1 0 2000 71200 Sep 28 15:03 netd
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 netstat -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 newfs_msdos -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 notify -> toolbox
-rwxr-xr-x 1 0 2000 5304 Sep 28 15:03 nv_hciattach
-rwxr-xr-x 1 0 2000 13492 Aug 1 2008 nvcap_test
-rwxr-xr-x 1 0 2000 5424 Aug 1 2008 nvremotell
-rwxr-xr-x 1 0 2000 5420 Sep 28 15:03 nvtest
-rwxr-xr-x 1 0 2000 18188 Sep 28 15:03 pand
-rwxr-sr-x 1 0 3004 26056 Sep 28 15:03 ping
-rwxr-xr-x 1 0 2000 191 Dec 23 2011 pm
-rwxr-xr-x 1 0 2000 141868 Sep 28 15:03 pppd
-rwxr-xr-x 1 0 2000 141868 Sep 28 15:03 pppd_btdun
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 printenv -> toolbox
lrwxrwxrwx 1 0 0 7 Sep 29 19:55 ps -> toolbox
-rwxr-xr-x 1 0 2000 1014 Sep 28 15:03 ps3service
-rwxr-xr-x 1 0 2000 5320 Sep 28 15:03 python
-rwxr-xr-x 1 0 2000 166808 Sep 28 15:03 racoon
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 reboot -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 renice -> toolbox
-rwxr-xr-x 1 0 2000 188 Aug 1 2008 requestsync
lrwxrwxrwx 1 0 0 7 Sep 29 19:55 rm -> toolbox
-rwxr-xr-x 1 0 2000 5376 Aug 1 2008 rm_ts_server
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 rmdir -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 rmmod -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 route -> toolbox
-rwsr-s--- 1 0 2000 9448 Sep 28 15:03 run-as
-rwxr-xr-x 1 0 2000 5304 Sep 28 15:03 schedtest
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 schedtop -> toolbox
-rwxr-xr-x 1 0 2000 9396 Sep 28 15:03 screencap
-rwxr-xr-x 1 0 2000 34168 Sep 28 15:03 screenshot
-rwxr-xr-x 1 0 2000 13600 Sep 28 15:03 sdcard
-rwxr-xr-x 1 0 2000 45920 Sep 28 15:03 sdptool
-rwxr-xr-x 1 0 2000 173 Aug 1 2008 send_bug
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 sendevent -> toolbox
-rwxr-xr-x 1 0 2000 13492 Sep 28 15:03 sensors-config
-rwxr-xr-x 1 0 2000 5352 Sep 28 15:03 sensorservice
-rwxr-xr-x 1 0 2000 13544 Sep 28 15:03 service
-rwxr-xr-x 1 0 2000 9608 Sep 28 15:03 servicemanager
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 setconsole -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 setprop -> toolbox
-rwxr-xr-x 1 0 2000 5352 Aug 1 2008 setup_fs
lrwxrwxrwx 1 0 0 4 Feb 6 2012 sh -> mksh
-rwxr-xr-x 1 0 2000 9524 Sep 28 15:03 sixpair
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 sleep -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 smd -> toolbox
-rwxr-xr-x 1 0 2000 46364 Sep 28 15:03 stagefright
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 start -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 stop -> toolbox
-rwsr-sr-x 1 0 0 22364 Sep 28 15:15 su
-rwxr-xr-x 1 0 2000 5352 Sep 28 15:03 surfaceflinger
-rwxr-xr-x 1 0 2000 192 Dec 23 2011 svc
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 sync -> toolbox
-rwxr-xr-x 1 0 2000 5300 Sep 28 15:03 system_server
-rwxr-xr-x 1 0 2000 67096 Sep 28 15:03 tc
-rwxr-xr-x 1 0 2000 17640 Sep 28 15:03 tegrastats
-rwxr-xr-x 1 0 2000 13904 Sep 28 15:03 tf_daemon
-rwxr-xr-x 1 0 2000 104964 Sep 28 15:03 toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 top -> toolbox
lrwxrwxrwx 1 0 0 7 Feb 6 2012 touch -> toolbox
-rwxr-xr-x 1 0 2000 91820 Sep 28 15:03 touch_fw_update
-rwxr-xr-x 1 0 2000 3391 Aug 1 2008 uiautomator
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 umount -> toolbox
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 uptime -> toolbox
-rwxr-xr-x 1 0 2000 5304 Sep 28 15:03 vdc
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 vmstat -> toolbox
-rwxr-xr-x 1 0 2000 75288 Sep 28 15:03 vold
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 watchprops -> toolbox
-rwxr-xr-x 1 0 2000 9480 Sep 28 15:03 wifimacwriter
lrwxr-xr-x 1 0 2000 7 Dec 23 2011 wipe -> toolbox
-rwxr-xr-x 1 0 2000 45904 Sep 28 15:03 wminput
-rwxr-xr-x 1 0 2000 608680 Sep 28 15:03 wpa_supplicant
-rwxr-xr-x 1 0 2000 21788 Sep 28 15:03 wvdrmserver
-rwxr-xr-x 1 0 2000 17644 Sep 28 15:03 xaplay

Things to take from this? Well, never EVER let a busybox installer touch /system/bin, no matter how much it insists on being allowed to do so. If an app isn't happy using /system/xbin; **** it, it's a piece of ****.