• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Booting OS9 on newer (unsupported) macs Part II

bd1308

Well-known member
So starting from where another fellow left off here:

viewtopic.php?f=15&t=11366

viewtopic.php?f=3&t=9967&start=0

https://discussions.apple.com/message/1542636?messageID=1542636#1542636?messageID=1542636

http://ameblo.jp/jozenji/theme-10002170412.html

So the plan is to see if I can boot my Powerbook5,8 using Mac OS ROM 10.2.1. Looking at the Apple Hardware Test file called "AHT_Bootinfo" it appears to be a small version of the Mac OS ROM that calls via OpenFirmware the diags file, which is built in Objective-C. Why it appears to look like OS9 I dont know...

Thats all I have for now.

 

LCGuy

LC Doctor/Hot Rodder
On a machine of that age, it may or may not be Mac OS 9, but there's no guarantee - even on newer machines (even Intel Macs!), AHT uses the Apple Platinum interface for whatever reason, as does the diagnostics software used by Apple techs.

 

bd1308

Well-known member
The recent problem Ive been having is that I can setup a HFS+ volume with a System Folder (blessed) on a CF card using my TiBook 400, but I cant *boot* from that volume either from USB or PCMCIA....When holding down option I dont see the volume listed. And when rebooting normally and checking the volume using Disk First Aid, it tells me that there's problems with the volume.

But I've done this exact thing using my 1400cs, and was able to boot from it. Are NewWorld macs not capable of booting from PCMCIA?

 

CC_333

Well-known member
bd1308: Did you make sure the volume has Mac Os 9Drivers installed? I assume you checked that contingency, but I will ask anyway.

Also, you can try formatting it as HFS Standard and see what happens.

Are NewWorld macs not capable of booting from PCMCIA?
I'm pretty sure they are. Why wouldn't they be? I could test and see for myself.
Good luck,

c

 

bd1308

Well-known member
I formatted the CF card in OS9 using Disk Utility. I would assume it was formatted as a standard HFS (what OS8 used to call HFS+). It also could be something in the partitioning scheme I had used when setting the disk up. I'll try again tonight. It just seemed strange something I could do (boot from PCMCIA CF) on my 1400c I couldn't do from a later model powerbook (TiBook 400)

 

LCGuy

LC Doctor/Hot Rodder
I have an eSATA card which I use with my TiBook 500 - I've never been able to boot from it.

 

bd1308

Well-known member
I believe booting from HD, CD or Fireware are the acceptable bootable devices in NewWorld macs, whereas OldWorld macs could boot from SCSI,CD or PCMCIA. I think anything post-PowerPC can boot from wherever.

I'm going to try to attempt this again this weekend using a CD. I can, in theory, make an ISO of 9.2.2, trade out the Mac OS ROM file with the 10.2.1 version, then see if the CD will boot. It's clear that this version of the Mac OS ROM removes the MacRISC2 limitiation, instead allowing all "MacRISC." machines to boot from this version of ROM. From what I know of the boot process, the following happens:

1) OF (OpenFirmware) recognizes and orders devices it knows about.

2) OF Looks at each device, ordered by first what you selected (stored) in Startup Disk control panel as your preferred device, and then opens that device looking for a Mac OS ROM file.

3) Once a suitable ROM file is chosen, its contents are copied into a location in memory to be parsed and run.

4) The program runs, loading the bitmap of the happy mac, and then proceeds with the boot process, booting from the already-valid device selected by OF.

If i'm wrong here, let me know.

 

Dennis Nedry

Well-known member
When you mention making an ISO of 9.2.2, what does this mean? Are you going to rip a bootable 9.2.2 installer CD to an ISO file?

Making an ISO of a bootable 9.2.2 CD preserves the blessed system folder and CD disk driver I'm pretty sure. To my knowledge, you can not modify files on an ISO though, so they are read-only when you mount them. Making a modification would require you to rip into a read/write disk image format, or convert the ISO into such a format.

I have two concerns with whatever writable disk image you make it to that allows you to swap Mac OS ROM files:

  • Keeping the system folder blessed: it may unbless if the system folder is copied to a read/write image, I'm not sure
  • CD-ROM driver: At least on older Power Macs, bootable CDs had to be burned with a CD disk driver in order to be bootable, even if they had a blessed system folder. Disk Utility and OS X versions of Toast do NOT do this.


The only way that I am aware of to burn a customized Mac OS 9 bootable CD is to do it on a Mac booted from Mac OS 9 and using Toast. I don't recall, but there may even have been a checkbox in Toast that you had to click for the CD disk driver.

I just wanted to write down everything I know about bootable OS 9 CDs here because I have had absolutely terrible experiences trying to make them bootable.

 

bd1308

Well-known member
Here's what I've done thus far:

I tried to manipulate 9.2.2 on a CF card -- no dice, neither my TiBook 400 or my AlBook 1.67 would read the OS from CF or from USB via the openfirmware system volume "picker".

I then tried to copy the 9.2.2 CD to a DMG and copy out just the Mac OS ROM. I then burned the resulting image to a CD-RW. For some reason *BOTH* macs will boot from a USB CD-ROM, and the TiBook booted right up to 9.2.2. I didn't modify the new Mac OS ROM file, because I believe that '.MacRISC.' would include MacRISC2 and MacRISC3 machines (2 being machines that boot into OS9 and 3 being machines that boot to OSX). That being said, the resulting boot CD did work on the TiBook (my control machine) and did not work on the Aluminum powerbook.

It could very well be that the machine i'm using for this test is just too new. The OF system "picker" does read the CD, but it doesnt show up on the list. I tried booting from the internal drive and from the USB DVD-RW drive. The DVD-RW drive worked and booted the control machine. There's got to be something in that Mac OS ROM file that needs to be changed, but i'm not sure changing 'MacRISC.' to 'MacRISC3' is going to do the trick. I believe there's some function that needs to be looked at inside of the ROM file that determines whether or not the bootable volume is applicable to boot this machine.

 

bd1308

Well-known member
http://blog.litot.es/2006/03/02/boot-from-cd-in-open-firmware/

http://mac.linux.be/content/guide-open-firmware-apple-bios-0

Digging around in Open Firmware I get closer to booting OS9 from my Powerbook G4 1.67:

0 > boot hd:,\Mac%20OS%20ROM load-size=2aad16 adler32-6fa3f548

parsing

Bootinfo is not supported

0 >

So I need to edit the CHRP-BOOT section for sure, but this is really good news (so far). It means that the OF system chooser (Booting with option held) is actually *reading* the Mac OS ROM file and throwing it out on purpose....

 

bd1308

Well-known member
Problem #2: There's a script that gets executed to determine whether or not to continue loading the ROM into RAM, or just puke all over itself. So there's still some digging, but at least I can test this on the new powerbook.

I accidentally changed the COMPATIBLE section of the chrp-boot section and bricked my install of 9.2.2 on my TiBook, but that should be easy to rectify.

If all goes according to plan, this *may* culminate in the remote possibility of using a XServe G4 to boot OS9 over firewire (if the onboard IDE chipset is indeed remarkably different, which I dont believe is the case). I've heard the MDD400 is similar to the XServe G4 1.0, so if anybody could look for a chip named PROMISE and tell me what the chip's ID number is, that'd help me determine if this is even feasible.

 

bd1308

Well-known member
I already looked at that image --- the AHT-BootInfo (the only Mac OS ROM-ish file on that CD) script does boot, but its a smoke-and-mirrors trick. It executes a file called 'exec' and that file is coded in Objective-C which came from Next which means its not what we're looking for. It only looks like OS9 because thats the way they wanted it to look. It could be that somthing in the ROM-to-RAM dump that we need to merge from BootX that just wont jive on a new mac. There's something else making MacOSROM not boot on a OSX machine, but I am starting to believe something in OpenFirmware is refusing to boot that file. I have found that booting directly from OF gives more detailed information than the "System Picker". I'll keep on messing with it though.

And I'll grab that image -- I had downloaded the same image for the Powerbook G4 Aluminum.

I think if it is possible to boot OS9 from a OSX-only machine, it'll be tricky.

 
Top