Re: Porting m68k/nommu to a new board.

Re: Porting m68k/nommu to a new board.

[Geert Uytterhoeven]

Added CCs.

On Fri, Dec 16, 2011 at 06:37, Daniel Palmer <me@danielpalmer.co.uk> wrote:
> Hi,
>
> I'm building a custom machine based around a 68sec000 (Fully static 68ec000).
> The "board" is a bunch of parts at the moment but I have written a workable
> simulator for the machine which I am using as a testbed for testing things
> like my custom video, DMA controller etc before creating the hardware versions
> in VHDL.
>
> I'm interested in getting mmu-less m68k linux (what used to be known as
> uclinux I guess, seems to be known as m68k/nommu now) running on the simulator
> and later on the real hardware.
>
> From what I can tell the nommu m68k port is still active. But does it actually
> work? All the details on similar hardware (like the older Palm pilots, Atari
> machines) is pretty ancient, around 2.0. Does anyone have a machine running a
> recent kernel? Were there issues getting it running?
>
> I did a bit of digging in the source and doesn't look like it should be too
> difficult to add the specifics for my machine.. I have a 16550 style UART
> emulated for I/O so I don't need to write a framebuffer driver at the moment.
> I'm open to any suggestions people have on how to approach this though.
>
>
> Please CC me as I'm not subscribed.
>
> Thanks,
>
> Daniel
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: Porting m68k/nommu to a new board.

[Greg Ungerer]

Hi Daniel,

> On Fri, Dec 16, 2011 at 06:37, Daniel Palmer<me@danielpalmer.co.uk>  wrote:
>> I'm building a custom machine based around a 68sec000 (Fully static 68ec000).
>> The "board" is a bunch of parts at the moment but I have written a workable
>> simulator for the machine which I am using as a testbed for testing things
>> like my custom video, DMA controller etc before creating the hardware versions
>> in VHDL.
>>
>> I'm interested in getting mmu-less m68k linux (what used to be known as
>> uclinux I guess, seems to be known as m68k/nommu now) running on the simulator
>> and later on the real hardware.

uclinux is/was mmuless support. m68knommu used to be the arch name for
m68k without mmu support. I just use Linux now, it has all been in
mainline for so long now.


>>  From what I can tell the nommu m68k port is still active. But does it actually
>> work? All the details on similar hardware (like the older Palm pilots, Atari
>> machines) is pretty ancient, around 2.0. Does anyone have a machine running a
>> recent kernel? Were there issues getting it running?

I run on ColdFire parts all the time. Right up to 3.2-rc5 :-)
It works great. But I don't have or regularly use any original m68k
core hardware. I occasionally compile for the 68328 target, so it
will compile, can't be sure if it still runs though.


>> I did a bit of digging in the source and doesn't look like it should be too
>> difficult to add the specifics for my machine.. I have a 16550 style UART
>> emulated for I/O so I don't need to write a framebuffer driver at the moment.
>> I'm open to any suggestions people have on how to approach this though.

With the m68k and m68knommu arch code now merged it shouldn't
be too hard to enable/configure all the pieces you have. Might take
a little hacking to make it work, but it should be close.

Regards
Greg


------------------------------------------------------------------------
Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@snapgear.com
SnapGear Group, McAfee                      PHONE:       +61 7 3435 2888
8 Gardner Close,                            FAX:         +61 7 3891 3630
Milton, QLD, 4064, Australia                WEB: http://www.SnapGear.com

Re: Porting m68k/nommu to a new board.

[Daniel Palmer]

Hi Greg,

Sorry for not replying sooner. Too much work :(

> I run on ColdFire parts all the time. Right up to 3.2-rc5 :-)
> It works great. But I don't have or regularly use any original m68k
> core hardware. I occasionally compile for the 68328 target, so it
> will compile, can't be sure if it still runs though.

I did a bit of poking around, I couldn't get the 68328 target to build.. I was 
going to have a play with it in xcopilot. It complains about some linker 
section missing .. but I started hacking it up anyway.. at the moment m68328 
depends on m68000 which in turn causes the 68328 platform stuff to build.
So I worked that a little so that 68000 is its own target that builds with 
some minimal startup code (so I can dump the resulting image into my emulator 
and see how far it gets.. I have a gdbserver in my emulator so I can fully see 
whats happening). I haven't managed to get an image out of it yet.. but I will 
have another go at the weekend.

I'm going to get an old palm pilot off of ebay and see if I can get the 68328 
target running too.

Thanks,

Daniel

Re: Porting m68k/nommu to a new board.

[Greg Ungerer]

Hi Daniel,

On 12/19/2011 12:24 PM, Daniel Palmer wrote:
> Sorry for not replying sooner. Too much work :(

No problem :-)


>> I run on ColdFire parts all the time. Right up to 3.2-rc5 :-)
>> It works great. But I don't have or regularly use any original m68k
>> core hardware. I occasionally compile for the 68328 target, so it
>> will compile, can't be sure if it still runs though.
>
> I did a bit of poking around, I couldn't get the 68328 target to build.. I was
> going to have a play with it in xcopilot. It complains about some linker
> section missing .. but I started hacking it up anyway.. at the moment m68328
> depends on m68000 which in turn causes the 68328 platform stuff to build.
> So I worked that a little so that 68000 is its own target that builds with
> some minimal startup code (so I can dump the resulting image into my emulator
> and see how far it gets.. I have a gdbserver in my emulator so I can fully see
> whats happening). I haven't managed to get an image out of it yet.. but I will
> have another go at the weekend.

Sounds good. Keep us posted on how you go.


> I'm going to get an old palm pilot off of ebay and see if I can get the 68328
> target running too.

Yeah, would be really nice to know what state the 68328 code is in.

I will compile it again too, and see if anything is obviously broken at
the moment.

Regards
Greg


------------------------------------------------------------------------
Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@snapgear.com
SnapGear Group, McAfee                      PHONE:       +61 7 3435 2888
8 Gardner Close,                            FAX:         +61 7 3891 3630
Milton, QLD, 4064, Australia                WEB: http://www.SnapGear.com

Re: Porting m68k/nommu to a new board.

[Greg Ungerer]

Hi Daniel,

On 19/12/11 12:24, Daniel Palmer wrote:
> Sorry for not replying sooner. Too much work :(
>
>> I run on ColdFire parts all the time. Right up to 3.2-rc5 :-)
>> It works great. But I don't have or regularly use any original m68k
>> core hardware. I occasionally compile for the 68328 target, so it
>> will compile, can't be sure if it still runs though.
>
> I did a bit of poking around, I couldn't get the 68328 target to build.. I was
> going to have a play with it in xcopilot. It complains about some linker

Yep, a couple of issues when building for the Palm/Pilot.
I just sent a couple of patches to m68k-linux that fix the main
problems. You will also want to disable CONFIG_FW_LOADER if you
have that enabled.

After that I can compile it all the way (I am building on 3.2-rc6).
No idea if it works though.

Regards
Greg



------------------------------------------------------------------------
Greg Ungerer  --  Principal Engineer        EMAIL:     gerg@snapgear.com
SnapGear Group, McAfee                      PHONE:       +61 7 3435 2888
8 Gardner Close                             FAX:         +61 7 3217 5323
Milton, QLD, 4064, Australia                WEB: http://www.SnapGear.com