How to install Mac OSx from USB on a PowerPC Powerbook G4

I recently had to install Leopard on a friend’s Powerbook G4 using only a USB drive because the internal DVD was busted. I thought it would be very easy but in the end it took me an evening and the better part of the morning. You see, the Powerbook G4 does NOT allow booting from a USB thumbdrive (only from external firewire disks or DVDs) and I am not really an expert of the internal workings of MacOSx.

It is possible though and one does not need to solder anything this time 😉

You need a big enough thumbdrive (at least 8GB) on which you’ll restore the Mac OS you want to install using the procedure outlined here : And you can  follow Ruth Gaudi’s excellent explanation here :

Procedure that worked for me

  1. Using Disk Utility, prepare a USB disk by deleting everything on it and create an “Apple Partition Map”
  2. Restore the MacOSX image onto the USB thumbdrive
  3. Using Disk Utility, find out the partition on the USB key that holds the OS you want to restore (in my case : it was called disk1s3, the last figure holds the partition number thus : 3 )
  4. Then you boot in the PowerBook OpenFirmware (the bootstrap that loads before MacOSX) by pressing the “Apple / Alt / O / F” keys at the same time right after you switch on the machine (before the chime sound)
  5. Type dev / ls and try to find something like “/disk@1” next to an entry named USB (in my case usb@1b,1)
  6. Type DEVALIAS in the command prompt and locate the short name of the USB entry you just found using dev / ls (in my case usb0)
  7. Make sure your USB key holds a file called “BootX”  with the tbxi attribute by listing the directory. In the following command, disk@1 should be replaced by what you found in Step 5, also every character is important (this includes colon, forward slash, etc.). Type dir shortname_found_in_step_6/disk@1:partition_number_found_in_step_3,\System\Library\CoreServices (in my case dir usb0/disk@1:3,\System\Library\CoreServices)
  8. If BootX is found with an attribute called tbxi then you’re all set and you can instruct OpenFirmware to boot from the USB drive : boot usb0/disk@1:3,\System\Library\CoreServices\BootX
  9. Hit enter and you should be booting from the USB drive. You can then install MacOSX as you would with a DVD.

Other (possibly useful) tidbits

  • The DEVALIAS command lists aliases to otherwise complicated paths to hardware (harddisk, USB, Soundcard, etc.) or software places (bootstrap). It is the equivalent of the Environmental Variables in Windows
  • tbxi is an alias to the binary boot loader. This very interesting articles is a good primer on the Open Firmware :
  • The default keyboard in Open Firmware is US so if using a swiss-french keyboard, remember that @ is shift-2, \ is the $ sign, / is the – key next to right shift, : is the é key
  • This should also work for other PowerPC machines (Mac Mini for example)
  • In case you wonder what OpenFirmware looks like, here’s a screenshot

82 Responses to How to install Mac OSx from USB on a PowerPC Powerbook G4

  1. _GNU_ says:

    Very nice! Other guides like this misled me a bit (specifically for the pbg4 15″ 1.67GHz).. “boot usb0/disk@1:3,\System\Library\CoreServices\BootX” was the correct line for me, thanks!

  2. Says can’t open file or device

    • did you do step 5 and 6 ?
      Can’t open file or device means that Openfirmware cannot access your key and it is usually because its path is incorrect or maybe you are trying to access another usb port.

  3. kevin says:

    When i get into Openfirmware it’s show up “USB Setup Error” and i’ve tried to ‘dir’ all of the USB there is nothing, it’s ‘cannot DIR’ all of them.

  4. Walt says:

    PowerBook G4 user. 15″ 1.67 GHz running 10.4.11. I am trying to install leopard using my iPod but I am not getting anywhere. If this is indeed possible, please help me. I’ve Done all that I could.

  5. vlad says:

    same as Walt trying to install on 15′ 1.67ghz running 10.4.11 any help on installing via ipod would be grateful!!

  6. Daniel says:

    Thank you so much for your help, this saved my 17″ Powerbook G4.

  7. Awesome, this worked a treat for me!


  8. dolls says:

    Hey, I can help more clearly how to do all this.Until now I had to do with Mac OS and do not understand.Make a video tutorial if you can

  9. Thargie says:

    Can’t OPEN the DIR device

  10. me says:

    I’m positive that my dir path is correct, but I am getting an error saying “Warning: sector size mismatch! can’t OPEN the DIR device” Any suggestions?

    • The only thing I can think of is there was a problem when the Disk utility was used to prepare the stick or maybe the stick is bad. Have you tried with another thumbdrive ?

  11. JC says:

    I’m getting “can’t open dir” error too..

    After typing dev / ls I get this:

    Which one should I use?

    Also after opening devalias I can only see these:

    usb0 corresponds to /usb@1b,1
    usb1 corresponds to /usb@1b

    Which should I use?

    Also I’d like to add its not made clear how to obtain the “real” drive name in disk utility, I called my drive “DONUT” to make it stand out but that’s not one comes up in terminal right?
    I don’t have a partition installed, it’s just one USB drive with only a carbon-clone of my OSX disk on it.

    • Hi JC,
      can’t open dir means the Mac can’t access your thumbdrive. Problem is I can’t really help there as I’m not an expert on OpenFirmware. What I find strange though is that you do not have a partition on your USB drive… Did you follow the procedure outlined here from the beginning ?

      Maybe others can jump in and help you more.

      • I didn’t install a partition as I didn’t have anything worthwhile on the disk so I just wiped it. Are you saying a partition is essential?

        If so I will put a partition on and try again.


  12. Actually… I don’t really know if a partition is essential as I’m not too familiar with the way Macs work… but I’m learning 😉
    What worked for me though is described here and it involved creating a partition on the thumbdrive (step 1).

    Good luck and I hope it works for you too.

  13. Monkeybutler says:


    Have used this method to successfully get Leopard onto an old 17 inch Powerbook with a dead optical drive – many thanks! However, I’ve now hit a snag trying to do the same with a G4 eMac. I’ve got through to getting the Leopard installer to boot from the USB, and then I can select a language, but the installation then hangs at the “Preparing installation” screen every time – the progress bar stops moving and nothing happens. I’ve tried leaving it for over an hour with no change. Any ideas?

  14. jamie says:

    Hi, trying to use these instructions to revive an old powerbook g4 laptop with broken diskdrive using a usb hard drive. I think I’ve done things correctly until step 5. When in OpenFirmware via Apple / Alt / O / F and typing dev / ls I don’t get anything that looks like: ‘something like “/disk@1″ next to an entry named USB (in my case usb@1b,1’
    Can anyone tell me what this indicates? The closest thing I have (from a long list) is:
    ff8b1b68: /usb-hid-class
    ff8b4680: /usb-ms-class
    ff8b73c8: /usb-udio-class
    Any advise much appreciated. Thanks.

  15. jamie says:

    Ah, I realize there was more to come after hitting space bar. Similarly to JC above I see:
    /usb@1b, 1
    /usb@1b, 2

    JC, did you figure this out? Thanks!

    • I gave up after dozens of attempts….
      I don’t know if I’m inputting the wrong text, or if there’s something wrong with the way I’ve put the OS on my USB drive.

      I’m actually tempted to buy a firewire cable and plug it into my USB drive, as it’s an old one and I *think* I remember it being “dual” compatible. If I can only find the cable…

      I was hoping to get a definitive answer from this forum, but I think the instructions need a bit more clarification in some areas, this is tricky stuff for non-pros!

  16. José Pedro says:

    Hi There, I have a powerbook G4 and I can’t install the macosx, the only thing that works is the Open Firmware comand line. I think the powerbook firmware is damage. Do you know how to instal the powerbook g4 firmware through the Openfirmare comand line? I have the latest firmware version to instal on it “PBook_FWUpdate_4.2.9.smi.bin” but I try all possible key combinations and nothing works, my last hope is the instalation by the openfirmware comand line.

  17. solor says:

    I’m on a powerbook 1.33 GHZ with a burned firewire and need to upgrade to leopard.

    I am using an external USB drive 8 GB with only Leopard on it (partition 10)

    I did a pram reset.

    in OF my disk pattern is pci@f2000000/usb1b,1/disk@1

    By “devalias”the above pattern corresponds to usb0

    following the post to my case I get

    dir usb0/disk@1:10,\System\Library\CoreServices fails ..

    any help !?

    thank you

    • solor says:

      After lots of failed attempts with the USB keys and drives, I ended up formatting the internal HD with a partition big enough to restore Leopard .dmg to it. From there it worked flawlessly.

      • Moonman says:

        I don’t understand can you explain further how you made it work? My issue is that when I ask for he directory it says can’t open DIR device. Try to boot and doesn’t. I resettled the pram etc too. I just got the computer off eBay so there is nothing but panther 10.3.9 on there. Formatting the hd drive works?

  18. Can SomeOne Help Me Please ADD Me On Skype smartybeast but when i do dev /is it says no device found ok
    and im using this 8gb thumb drive ive already booted the leopard on too also dont know what you mean by the partition number?

  19. No need for all that work! Just type the following:

    boot ud:,\\:tbxi and it boots Leopard and or Tiger right up!!! No need to point to BootX or anything at all. This is how I boot up from my USB devices on my G5, Pismo, and G4 PowerBook.

    • Erik says:

      Thanks! This made the trick after hours of experimenting with other parameters. I’m on a iMac G5 (isight) that I got from a friend and managed to screw up OS while cleaning up disk space.

      Many thanks!

    • Aaron says:

      when i type “ud:,\\:tbxi” and it seems to start booting but a circle crossed appears. any ideas?


      • Zach says:

        Have you worked out this issue? I have the same as you! I haven’t got a clue what to do?

    • Sos says:

      Mine just booted into the drive holding OS 9.22 on it.

      What worked for me:
      1) Use disk utility to restore leopard_install.dmg to 8GB USB drive
      2) Shutdown G4 Ti 1Ghz Powerbook
      3) Insert USB drive into port
      4) Turn on Powerbook, holding down “option” key.
      5) A boot menu appears, and you can select which startup volume you want using a GUI.
      6) Select the USB drive you made in step 1.
      7) Enjoy OS 10.5.x !

  20. DMT says:

    workz!!! boot my iMac G5 to 10.5.8 made via USB on my MBP..

  21. Shora says:

    When I try to boot, I get “unrecognized Client Program format”. Any idea?

    • Shora says:

      After many tries without success, I did it sharing the DVD drive from another Mac via Firewire cable.

      • Joe says:

        I am very interested on learning how to do the same, Shora. Could you please share the details? I will very much appreciate it. My PowerBook G4 17″ won’t even start-up in Target mode. Thank you.

  22. Joe says:

    Hi! Can anybody please share an OF line similar to “boot ud:,\\:tbxi” to make the computer start-up from a Mac OS X DVD inserted in the optical drive? Booting from the USB flash memory leads me to a Kernel message (after the Apple logo shows on the screen) that reads: “panic: We are hanging here…” and the booting process stops. PowerBook G4 17″ with damaged HD, only responding through Open Firmware. Thank you!

  23. Wisey says:

    This was a long shot but I was actually trying to boot the installer from a usb flash drive and also install the os to the flash drive. However, I couldn’t even get the installer to run. I used my fathers new MacBook Air to restore the installer from disc onto the flash drive. But even the Open Firmware commands wouldn’t work. I was speaking to an Apple certified technician on irc and he said that my particular machine doesn’t allow booting through usb and that the Open Firmware hacks will not work. He said that some later Open Firmware based Apple machines allowed you to do this but not mine. My internal hdd and internal optical drives are broken, this is the reason I tried this method. My only option left is to install another internal hdd and run the installer through firewire. But the hdd currently inside was only 2 months old before it broke and my technician said that it was probably a fault elsewhere in the machine that caused the extremely short life span of this new hdd. I think it is a new machine guys.

  24. Joe says:

    Sounds hard to accept it is time to buy a new one, when PowerPCs are amazing pieces of tech, I’d say. If one can afford it… I don’t know what internal failure can actually cause a brand new drive to die in a couple of months, but that scares! Meanwhile, I have not been able to startup from the USB yet, and I am pretty sure that the solution has to be replacing the damaged internal HD. I read somewhere else that in certain conditions the computer enters a sort of “hanging” trying to read or detect the drive, making it impossible to boot from a different device. And even if successfully booting from the USB flash memory was possible, if the internal HD is really dead, you can not get much farther than confirming that you have to buy a new drive. For now, I was able to eject the stuck dvd from the optical drive, using some sort of “The Croods” method, by inserting a thin plastic card through the optical drive slot and forcing the disc inside to stop spinning, and at the same time commanding “eject cd” from Open Firmware. Obviosuly my copy of OS X install dvd was permanently damaged and there is a risk to damage the superdrive itself, but well, these are the risks of fixing it in on your own, I guess.

  25. Ivan says:

    Hi, i did everything that you have told in this forum, but i cant find a way more easier than this steps:
    1. From a compatible image of leopard with PowerPC, I mount it and restore it in the next step “2” and “3”
    2. I create a new partition in my g4 disk of 10 gb
    3. Then I restore this 10 gb partition with my previous image I create in USB
    4. Restart my g4 and I have press Alt key before the sound of beginning
    5. Chose my leopard image to boot it
    6. Install leopard from 0 in my root partition

    • Matt says:

      I just want to reach through the interwebs and kiss you (or, ahh, buy you a few drinks haha). I’ve been trying for 2 days to get my system to boot from various USB keys and have had no luck (I’ve tried every method of copying the install image and also of booting from the USB key). Then I saw your post and tried it, booted straight in! It’s now happily installing and I’m a thousand times less stressed, and since today’s Friday it means I’ll actually enjoy my weekend! Genius, thanks!

  26. […] 07:08 AM I'll +1 that but if you're feeling adventurous . . . . How to install Mac OSx from USB on a PowerPC Powerbook G4 | Lifedigital2010's Blog External hard disk acquisition addict – but admitting the problem is the first step to a […]

  27. Andy A says:

    Eventually worked fine for me after a several hours of trying on iMac G5 with broken DVD. For those respondents who reported getting a crossed circle – I had this problem too. I had created my bootable Leopard memory stick using Windows and then again in OS X 10.8. My next mistake was to format my memory stick in GUID. You need to format it using Apple Partition Map as stated above using the option button in Disk Utility. I used the Disk Utility restore option on the same 10.4 iMac G5 system, then used the above process. This fixed it for me.

  28. Nick says:

    Hi, I am having difficulty following this guide. When I start up my PPC G5, it shows a folder with a question mark in it. When I follow the OF, type in all that stuff above, etc etc… I get nothing. Please can somebody help??????

  29. This works. One of the things that i got stuck on was that i was using a USB3 Stick. OSX was seeing the USB once it was fully loaded into the operating system – i was able to complete most of the steps; but i didnt realize that it cant see it after the
    Cmd-Opt-O-F terminal screen. (i assume because the .kexts were not loaded)

    Also G4’s cannot boot from a usb even when holding the Option button down at boot. Just want to reiterate this and this is why many are on this page.

    If you are getting a grey screen with an error symbol (circle with line thru it) it could very well mean that you did not specify the PROPER PARTITION on your USB!!!!

    It is not enough to point to the “disk@1” you need to point to the “disk@1:10” for example.

    Last thing that tripped me up: Get a proper ISO or DMG file! Not a bootable image from super duper and such. It could work…but if you get an authentic installer dmg, it should definately work!

    Good luck!

  30. Serdar says:

    Thanks .Simple instruction. Just upgraded Tiger to Leopard with flash drive. Great

  31. Sebastian Elijah Laluz says:

    It says “LOAD-SIZE is too small” what do I do?

  32. sorry man can’t help you there. try and follow exactly the instructions and it should work, openfirmware is picky about the device naming…

  33. B-Damaged says:

    Perfect, it worked fine for me. Just had to adjust the device dir according to instructions.

  34. Connor Matthews says:

    I just get stuck at an Apple logo with the spinning wheel forever. The USB drive does flash for a couple of minutes as it seems to be loading files but then it stops and it sits there just spinning eternally. Any ideas?

  35. jaguer says:

    Hellow ! Need help my pbg4 doesn’t find USB or DVD, when I hold down option key it shows the arrow and retry option what can I do

  36. Andres says:

    ThanK you so much!!

  37. Simon says:

    Do you think this method would work to install Debian or Ubuntu on an eMac G4?

  38. Simon says:

    Thank you anyway. I’ll try it over the summer and let you know.

  39. philicent says:

    thanks for or write up.
    I will try dis method, I am really confuse I pray this works out

  40. Dale says:

    Thanks for post. Solder is spelled wrong. You put soldier. 😉

  41. luis navidad says:

    pleas help me, I need download leopar, I have a porwe g4, but it have a tiger and can not install office or openoffice…. help me pleas

  42. Neighbor was throwing out an old mac and I said I would take it. I was able to get an install disc (a version just higher than what was said possible for the laptop but that others said will still function) on usb.

    Your instructions worked like a charm after trying several other things.

    Using left side USB port on Powerbook G4 15″:
    boot usb1/disk@1:3,\System\Library\CoreServices\BootX

    This WORKED!


  43. David R says:

    If you’re having problems with the USB device not showing up, type
    before doing anything else. This will rescan the USB bus.
    This works on my 12″ 1.5GHz PowerBook.

  44. Tom! says:

    it helps me very much! I spend 4 days to fix the powerbook, but then I found this instructions! thanks a lot!

  45. Scammerrevolts says:

    Can you add a download link for leapord 10.5 I have been looking all over but all I get is a Kerbal panic or a file that won’t start installing when I boot at all.

  46. Drew says:

    Dude! Thanks so much. I was pulling my hair out with is old rig I found! Actually scored this PowerMac G4 as well as another MacBook Pro and coming from the PC world I’m pretty impressed at the build quality and have been interested in OsX since I realized it was unix based years ago but could never get it working right on a couple ‘Hackintoshes’ I put together So ya mine is a 1ghz model with the Raedon Graphics, built in fire wire and wifi! @2006 wow,cool. It ran decently actually considering it only had 500k ram?! Lol, Ive ordered 2 gigs for it and think she’ll be quite usable for someone for casual surfing or word processing, reading. Beautiful screen! But ya after days of reading and fumbling around with iso’s and resetting smc and NVRAM et all, to finally getting into the firmware and learning the directory structure! Abit different from DOS for sure. But yea..the key for me was the command ‘probe-usb’.Firmware wasn’t finding it otherwise. I kinda figured since i couldn’t seen a ‘disk@1’ anywhere after the ‘usb1b’ when using the dev / ls command.. but after probing there it was…And I knew I was close! So ya your little devalias detail here I just found showed me the right path and boom the dir command actually worked and there was BootX ! I’m excited lol. Like 5 old accounts have been erased hd wiped clean for a fresh Osx 10.58 that’s installing right meow =) Been a learning experience! Thanks to all! Peace!

  47. Hello, if anyone could help me please … I’ve been there for 1 month and even without solving anything, I always get”not open ”. Please write to my mail or here. ….
    I have read all the comments and still nothing.

  48. Nick says:

    How can you find the directory if using transmac to make a osx boot usb? As i dont have other mac to do this.

  49. Camellion says:

    That works perfectly. Thx

  50. Mark says:

    Thanx alot, worked great, real magic.
    Revived an old G4 desktop, onto the old G5

  51. Vilo K says:

    I was fighting with this for DAYS. I tried like 6 different syntaxes for the dir and boot commands, tried aliasing, reading dev trees, NEVER got anything. I tried formatting the USB drive using MBR, GUID, apple partition map, nothing. I tried “restoring” the DMG file to the USB stick in multiple fashions. Nothing worked, dir listing never showed in OF, boot always said “load-size too small”. FINALLY I figured it MIGHT have something to do with the fact that in the DMG, there are 3 partitions, 1st 32kb, 2nd ~532MB, 3rd ~7.5GB. That is the 10.5.6 install DVD DMG from torrent (I was trying to get my G5 quad working). The “restore” in HIGH SIERRA on my macbook only restored ONE partition, or TWO, but never restored the “unknown format” second partition. I learned that old PPC G5 can’t read JOURNALED filesystem. In high sierra you can’t easily format to standard (non-journaled) HFS+. Then I just thought:

    – why don’t I just DD the whole thing?


    sudo dd if=/dev/rdisk3 of=/dev/rdisk2 bs=4m

    In my case, disk3 was the MOUNTED dmg in high sierra on my macbook, disk2 was the usb stick.

    DONE. Booted in open firmware with “boot ud:,\\:tbxi” one command, nothing more needed! Hope this helps somebody running modern os x like high sierra to make bootable USB leopard install sticks.

  52. Bryan Roberts says:

    Hello Everybody! Well first of all excuse my English if is somewhat not well written.

    Well I tried the method above, but there was something bugging me, I did a Leopard USB stick, but I did it under macOS Sierra, in an intel machine, so, after thinking a lot, I was wondering if that could in any way affect the result.

    So the case was this: I got a PB G4 17″ aluminium, I believe the third model (more info The PowerBook G4/1.67 17″ (Al) features a 1.67 GHz PowerPC 7447a (G4) processor with the AltiVec “Velocity Engine” vector processing unit and 512k on chip level 2 cache, 512 MB of PC2700 DDR SDRAM, a 100 GB Ultra ATA/100 hard drive (5400 RPM), a slot-loading 8X “SuperDrive”, a Firewire “800” port, built-in Bluetooth 2.0+EDR and AirPort Extreme (802.11g), ambient light sensor keyboard, and ATI Mobility Radeon 9700 (4X AGP) graphics with 128 MB of DDR SDRAM in an attractive aluminum alloy case with a 17″ widescreen TFT display (1440×900 native resolution) for 35€ and it was sold as it, almost new, with 2 dents on the corners, but the seller said that the machine showed a folder with a question mark and stoped there, so I thought that it was just matter of installing a new OS and it was done.

    I Tried the CD or DVD boot with the discs that came with the machine, and even the reader took the DVD it failed to read it and ejected. Then I tried the Ethernet boot and didn’t work, so I tried the USB bootable stick, but even I followed the instructions above I still had the message that the Mac couldn’t access the USB, so I wasn’t so sure if it was hardware (broken port) or software, then I found another page where the instructions complements this one


    And there was something that helped me, the instructions above says “If BootX is found with an attribute called tbxi then you’re all set and you can instruct OpenFirmware to boot from the USB drive : boot usb0/disk@1:3,\System\Library\CoreServices\BootX” but how can I know about the tbxi attribute?

    Well read this:

    4. Here is the moment of truth. If this step does not work, I have had very limited success getting a machine to boot off USB2. In Open Firmware, type devalias, and you should get a list as output. In this list, look for ud, usually below where you see hd (ud is “USB Disk,” I presume). If found, it will usually have beside it /pci@f2000000/usb@1/disk1, or something similar. Again, if you see this, I have not had this fail yet.

    5. Now type printenv boot-device, which will usually get you output of boot-device hd:,\\:tbxi. (See where this is going yet?)

    6. Type setenv boot-device ud:3,\\:tbxi where the number after the colon corresponds to that partition number we found in step two. You should get an ok back.

    7. Type printenv boot-device, and you should see the change displayed already. Something like:
    boot-device ud:3,\\:tbxi hd:,\\:tbxi”
    Type mac-boot and cross your fingers.

    So basically we´re altering the firmware to “copy” the tbxi attribute from the boot device that is the HD to the USB, so now the system boots either from the HD or the USB, and It did.

    I ran the installer and the disk utility and the machine didn’t show a HD on the system, so I guess I need to open the MBP but at least I know it can boot from USB, either way I was going to upgrade the HD for a SSD.

    Greetings from 2019

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