Possibility to install Amiga OS 4

[MauryG5]

Good morning to all the Power community, in this discussion I would like to introduce the Amiga question that I haven't seen much to deal with for now but which in my opinion deserves being AmigaOS, an operating system written completely for Power processors. Do any of you know a way to be able to install Amiga OS 4 on our systems? If I remember correctly, I read that they put a sort of block for which only with an Amiga XE machine you can start the installation and run the software. Anyone know more about this story?

[ClassicHasClass]

Amiga OS 4 is not compatible with any OpenPOWER hardware, including Raptor family systems.

[mparnaudeau]

I confirm that there is no port of AmigaOS 4 on POWER machines. That would be great even if the OS will use a small part of the hardware resources.
And even a BlackBird will be very expensive for this exclusive usage.

@MauryG5 I've never heard about a restriction like the one you described. AmigaOne XE is an old model of NG machines (that is to say standalone PPC motherboards).

[MauryG5]

Then I misunderstood the restriction.  I had read an article some time ago that seemed to say this but evidently what I deduced is incorrect.  But sorry at this point the question arises spontaneously, how come it has no compatibility being even Amiga OS 4 written entirely for Power processors?  What makes it incompatible?

[ClassicHasClass]

It doesn't know how to deal with the architecture; it's written only for PowerPC-based Amigas, which despite being the same family of CPU, have very different system facilities.

[MauryG5]

I understand this but I also know that in recent years the Power Isa instructions also have all the PowerPc instructions ... there will be something else that prevents execution so ...

[mparnaudeau]

Globally, the user instruction set is compatible whatever the processor. And the effort on PowerISA, for years, tends to consolidate and officialize a single ISA, with processors complying with a version or another (some PowerPC processor don't comply why any versions of the PowerISA).

I would say that the main differences concern the processor implementation (priviledged instructions, cache and MMU management, ...) but the processor support is not enough, there are also to manage the boot and the devices (always new drivers to write).

[MauryG5]

I understood then you tell me that the processor is not enough but there are other features that prevent support for that operating system ... Too bad I would have tried it willingly, I consider Amiga OS the best operating system ever written on computers and since the machines on which turns are really badly made, unfortunately it has no possibility of further development remaining confined where it is currently ... A real shame ...! I read someone's experience on the X5000 and says that it was really negative and that these machines are badly made even in terms of architecture and that they are a joke, especially for the price they have ...

[mparnaudeau]

That would be great to have AmigaOS running on Blackbird! At the moment, I think that's only possible under emulation ... with qemu since the support of the Sam460 config seems to be good enough. I would like to try ... when I will have a Blackbird (not ordered yet and I don't know when it will happen).

I didn't have the same negative feedback from the X5000. About the price, unfortunately, this is mainy due to the small amount of units produced.

I agree that some choices were unfortunate, notably about the CPU choices. And in my opinion, a reduced number of boards or variants have been better.

[MauryG5]

I'll post the message that this person sent on the Italian Amiga forum, his is a direct experience so you can better understand what I said in the previous post.

today we talk about the x5000 / 20 which is the one on the market.
the x5000 in the P5020 configuration has a ram access equal to a 2001 p4. it is true that the ram it mounts are ddr3 1333mhz but not used with access results equal to 2Gb / s the situation worsens if the memory is in writing where performance drops to 1.5 Gb / s.

to make a comparison the quad g5 machine of 2005 mounts ddr2 667mhz with 7 Gb / s in r and w and 9.5 Gb / s if altivec operations are used.

also the machine mentioned above has serious problems on dma especially if pci slots are used. using pci slots the maximum allocated memory is 3.5 Gb.
the P5020 CPU manages a maximum of 512Mb on the PCI and PCIE slots. to put it simply: if we mount 2 modern GPUs that use 256Mb cad opening on the pcie and a sound card or other on another pcie slot we have serious performance problems and serious system instability.

lshw or lstopo on linux presents a totally senseless hardware topography where there is an out of the norm device with bus and bridge nesting inside each other and not on the same branch and same level as happens on any machine that is x86, arm, powerpc to the world. to be clearer imagine 1 bus and many bridges one nested in the other up to 5 nests and then end in a bridge with another bridge with the pci to pcie converter and a two pci ...

the pcie's performance is currently worse than the worst agp bus of the worst amigang machine ... writing is almost equal to cyberstormppc on amiga 4000.


the l3 cache is non-existent or better only has functions of caching the network packets .... but the beauty is that the internal lan do not work both on amigaos and on linux they are in dummy for the dma problems described above.

uboot is the one in 2014 who manages and maintains uboot is a volunteer who has serious problems with megalomania and wisdom ...
the writer has repeatedly suggested to the gentlemen cat and fox to contact m3x but with poor results ... maybe because m3x you pay the megalomaniac is free.

I forgot that the p5020 has whole performance not bad but the CPU is suffocated by the poor performance of the ram.

the cyrus is a machine that already exists in varisys what they added was a + that I think is just the beautiful and useless xorro.

for now it's all about x5000 the amiga that wasn't there and it was better that it remained that way.

This is what he posted on the forum, then I don't know specifically but I don't think the truth is far away because you understand that the guy knows what he says ...

[AbstractConcept]

It doesn't know how to deal with the architecture; it's written only for PowerPC-based Amigas, which despite being the same family of CPU, have very different system facilities.

Are you specifically referring to the firmware? At a glance, AmigaOS seems to call its firmware Kickstart, but according to Wikipedia since version 4 (when Amiga switched to PowerPC) it is run off of the disk rather than ROM. While looking around, I came across an AmigaOS4.1 boot process blog post, which would suggest that AmigaOS 4's Kickstart is in fact more of a bootloader, and a portable one at that, seeing as it has already been made to run on top of IEEE 1275-1994 (Open Firmware), CFE, and UBoot.

Maybe porting AmigaOS 4.1's Kickstart to OpenPOWER firmware really is not that unfathomable...

[MauryG5]

At this point I also think it is a problem related to the firmware because in themselves the CPUs are of the same family and therefore on Power 9 we have all the Power and PowerPC instructions and therefore also in my opinion with a firmware written on purpose, it is possible to run Amiga OS4 ... If anyone had the opportunity to write it it would be a nice thing ...

[MPC7500]

That would be great to have AmigaOS running on Blackbird! At the moment, I think that's only possible under emulation ... with qemu since the support of the Sam460 config seems to be good enough. I would like to try ... when I will have a Blackbird (not ordered yet and I don't know when it will happen).

Also AROS and MorphOS should work. They also supports 460ex boards.

[MauryG5]

Yes good, these two mentioned by you also work, I had tried to download Morph OS thinking that maybe it had a more compatible firmware with Power but nothing even works directly. It is to be seen how it works in case of emulation, I have never been in favor of emulators, they usually do not have the same performance as when it is directed ... Then I can be wrong, maybe for Amiga OS there is no problem because is slimmer and lighter than Linux ...