Re: Kernel versions 6.x don't boot on Amiga 4000

Michael Schmitz
2023-02-27T07:20:10Z

Hi Finn,

Am 27.02.2023 um 18:55 schrieb Finn Thain:
> On Mon, 27 Feb 2023, Michael Schmitz wrote:
>
>>>
>>> Bisected to commit 376e3fdecb0dcae2 ("m68k: Enable memtest
>>> functionality") in v5.17-rc1. Reverting that on top of latest fixes
>>> the issue.
>>
>> Yes, I'm sorry to say that was the only likely candidate. Can't see why
>> though - are Macs all configured to have RAM start at address zero, and
>> possibly contiguous, Finn?
>>
>
> I don't really understand your question. This was not a Mac patch. The
> issue seems to be about the locations initrd_start and initrd_end in
> relation to the various memory segments (?)

I didn't realize that - thanks for pointing this out.

>
> This seems to be the same bug that was raised about 6 months ago... I had
> thought it was a bootloader bug but I'm out of my depth here.
>
> https://lists.debian.org/debian-68k/2022/09/msg00047.html
> https://lists.debian.org/debian-68k/2022/09/msg00051.html
> https://lists.debian.org/debian-68k/2022/09/msg00055.html

I had forgotten all about that one... Thanks for jogging my memory!

In this case though, the bug happens when the ramdisk is loaded in the
lowest address memory chunk, at least at a lower address than the one
the kernel runs from.

The crashes in the above thread were all from boots where the initrd got
loaded at the end of the memory chunk the kernel runs from.

Time to try using copy_from_kernel_nofault() to copy the ramdisk into
its final location? (just kidding)

Cheers,

Michael