Re: lemote-3a-itx-a1101 kernel and pmon

>>>>> "James" == James Cowgill <[email protected]> writes:

> Hi,

> On Sun, 2016-01-17 at 06:39 +0100, David Kuehling wrote:
>> long time ago I was told that I need a newer PMON to boot recent
>> linux kernels [5], but then read on debian-mips about problems after
>> PMON upgrades [1].
[..]

> So the old PMON in those machines (only itx-a1101) has a bug where it
> loads the kernel at an address to close to the address the bootloader
> is stored at. If the kernel being loaded has a large bss section (or
> is large in memory for any reason), PMON will overwrite itself and
> crash.

> The bug appeared after this kernel commit:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c46173183657bbdbe0d54a981c28807581648422which
> increased the size of the bss section to something like 20M on all
> Loongson 3 kernels.

> Back then I tried using PMON 4.something but it wouldn't boot any
> kernel I threw at it.

> In the end I patched the kernel to reduce the value of
> MAX_PHYSMEM_BITS from 48 to 35 and it worked again - I think this
> should be ok on all Loongson 3A machines.

> Hopefully if you try that, any recent kernel will work with the old
> PMON.

Ok, just to make sure I understood correctly: you never managed to make
the newer pmon 4 work with any kernels at all?  That would be somewhat
surprising, given that people were repeatedly told to upgrade PMON on
these Loongson3 boxes.

cheers,

David