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cyroz

macrumors newbie
Original poster
Aug 16, 2016
7
0
NJ SLC WA OR CA USA!!
Hey everyone. I'm not exactly sure where I should have posted this but figured since its PowerPC, some of you fans that have G5 hardware around maybe be able to take a shot at this. Hopefully this section should be okay.

I was looking to see if there is anyone here who is familiar with programming on PowerPC. First ill explain I'm no expert or programmer. but I do have some common knowledge. I'm NOT asking for anyone to do any magic for me I am just curious if this is possible, or if anyone can break down the process of how to load a rom from disk on a powermac G5.. I guess what I want to do is convert this to a bootable iso if at all possible.

I was interested in finding software recovery for a Xenon Alpha kit which was an Xbox 360 alpha. I have found a remote recovery which installs and updates the machine. but unfortunately you need to have a running version in order to use it. Now at this stage I haven't been able to find those recoveries disks and not even sure if one exists. I did some poking around and noticed the exe for the remote recovery should contain all the files that is needed to boot into the Xenon Launcher Menu... if you extract the exe the file contents are as follows...

one the left are the folders... the right is file contents..
XBOX - Xapi.dll
xbdm.dll

XBOXFLASH - connect.dll
xam.dll
xbase.dll
xnet.dll

XBOXROM - /000/xboxroma_1mb.bin

XDKSAMPLES - Dolphin
SceneViewer

XSHELL - banks
data
images
media
sounds
default.exe


each folder contains some files and I am curious...would it be possible to load this via a disk? what is required to load a rom? I am curious what process the machine goes through.

from what I read on an installed unit there is a xeboot partition? and the rom gets elf loaded? hoping some experts have any insight on this topic, It would be interesting if someone could get this loaded via disk or knows the process to getting a rom to load Screenshot (5).png

thanks for reading!
 

AC910

macrumors member
Jul 10, 2016
95
86
You'd have to look into Open Firmware as that what's on the powerpc macs that loads the OS.

However simply making an openfirmware compatible bootloader won't be enough as consoles are fixed single target platforms. So the binary in that xenon alpha expects a single set of hardware configured in a specific manner. In order to change any of that one would have to disassemble the binary and reverse engineer anything that interfaces with the hardware. Which will be a substantial portion.

Of course that's assuming you can find hardware that supports every instruction the binary requires and gives the output in the same format a well. That's highly unlikely as the 360 uses custom designed cpus and gpus. So one would probably have to rewrite large chunks of diassembled code to get around the different hardware.

So is it possible? Sure. Is it feasible for someone without at least a graduate degree in computer science? No.
 

cyroz

macrumors newbie
Original poster
Aug 16, 2016
7
0
NJ SLC WA OR CA USA!!
You'd have to look into Open Firmware as that what's on the powerpc macs that loads the OS.

However simply making an openfirmware compatible bootloader won't be enough as consoles are fixed single target platforms. So the binary in that xenon alpha expects a single set of hardware configured in a specific manner. In order to change any of that one would have to disassemble the binary and reverse engineer anything that interfaces with the hardware. Which will be a substantial portion.

Of course that's assuming you can find hardware that supports every instruction the binary requires and gives the output in the same format a well. That's highly unlikely as the 360 uses custom designed cpus and gpus. So one would probably have to rewrite large chunks of diassembled code to get around the different hardware.

So is it possible? Sure. Is it feasible for someone without at least a graduate degree in computer science? No.
[doublepost=1471574180][/doublepost]
I was doing some research and you are right but open firmware was stock the hardware was also stock so we have a model and hardware list just need to figure how to boot
 

AC910

macrumors member
Jul 10, 2016
95
86
[doublepost=1471574180][/doublepost]


I was doing some research and you are right but open firmware was stock the hardware was also stock so we have a model and hardware list just need to figure how to boot
I looked into the dev kit and yes it uses off the shelf power Mac.

So at a minimum you'd need to write a bootloader. Look at yaboot's source code which is the openfirmware bootloader for Linux for ideas how to go about it.

The real bootloader used in the dev kit may be doing more than just pointing the system at the starting executable though.

Also you say you have a remote updater. This probably isn't enough to actually run the system as it probably doesn't have all of the files required.
 

cyroz

macrumors newbie
Original poster
Aug 16, 2016
7
0
NJ SLC WA OR CA USA!!
I looked into the dev kit and yes it uses off the shelf power Mac.

So at a minimum you'd need to write a bootloader. Look at yaboot's source code which is the openfirmware bootloader for Linux for ideas how to go about it.

The real bootloader used in the dev kit may be doing more than just pointing the system at the starting executable though.

Also you say you have a remote updater. This probably isn't enough to actually run the system as it probably doesn't have all of the files required.
[doublepost=1471670710][/doublepost]
See that def helps lead me in the right direction. I know it sounds like a lot of work which I'm not saying it isn't. But with my familiarity with these recoveries and how the system works I believe we just need to be able to point it to boot like you said. Also their maybe missing things.. Such as a bootloader which in a very early xedk one recovery had a xeboot file which contained information on starting the bios rom and loading xshell and once the shell loads the default xenon launcher exe loads which is the os / dashboard. So I really believe the recovery has most everything we'd need in a lucky way if someone were to ever create a custom boot loader to get it running pretty much. Thank you again I'll continue to ask some os devs in different areas also. Any other input would be great too
 
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