Re: [Qemu-discuss] Coldfire 5282 Support

[William Mahoney]

> On Sep 4, 2017, at 3:11 AM, Thomas Huth <address@hidden> wrote:
> 
> On 01.09.2017 21:03, William Mahoney wrote:
>> Hello QEMU users.
>> 
>> I am interested in looking into a port for the Motorola Coldfire 5282. I saw 
>> that others in the Coldfire family were supported, like the 5208 eval board 
>> and the 5206 as a bare CPU. When I started looking into it I saw that 
>> several files (e.g. coldfire/flexcan.h and coldfire/intctrl.h) mention 
>> CONFIG_M5282 for conditional compilation. So I did:
>> 
>> ./configure —prefix=(etc.etc.) —target-list=m68k-softmmu,m68k-linux-user 
>> —extra-cflags=‘-D CONFIG_M5282’
>> 
>> and a make, and it churned away for a while. It built ivshmem-client and 
>> server, qemu-ga, emu-img, qemu-io, qemu-nbd, and qemu-system-m68k.
>> 
>> I expected to have it build emu-m68k but it did not, just the -system- 
>> version. 
> 
> It should be there - did you have a look at the m68k-linux-user directory?

This one’s "my bad". Fixed.

> 
>> The qemu-system-m68k does not list the 5282 as a valid CPU, so obviously my 
>> define is not all that is required. 
>> 
>> So several questions. 
>> 
>> 1) Is there really 5282 support and if so…
> 
> No, QEMU does not provide 5282 support. If you've spotted a CONFIG_M5282
> somewhere, that must have been in the sources of third party modules
> like U-Boot which we include in the QEMU release tarballs. But that are
> other projects, so you can not draw a conclusion from these submodules
> on QEMU in general.

Ah! I see, thanks. I will go back to the particular header files and see what 
they are related to.

> 
>> 3) The documentation only talks about running a linux kernel but I want to 
>> run an image that already exists and is in the flash on the device.
> 
> QEMU has the "-bios" parameter for loading firmware images. However,
> this is currently not wired up in the both Coldfire boards that QEMU can
> emulate (the Arnewsh 5206 and the MCF5206EVB). But it should be rather
> easy to add that if necessary, I guess.
> 
> You could also have a look at the "Generic Loader" device which can be
> used to load blobs, too. Run
> m68k-softmmu/qemu-system-m68k -device loader,?
> to have a look at the required parameters of the device.
> 
> Thomas

Thanks Thomas. One more question. Somewhere there must be a "what parts to look 
for where” document. You know, a “If you are interested in the device support 
for CPU XYZ, you look in the …XYZ directory” etc. I’d like to find this and/or 
anything else to clue me in before starting as to the level of difficulty to 
add 5282. I mean, I have decades of “C” background, I know the 5282 well, but 
am I going to be 10 days or 10 weeks?