Re: Removing dpkg arch definitions for uclinux-any?

Hi,

On 13.11.23 19:08, Guillem Jover wrote:

> I was checking for dpkg arch definitions to cleanup and stumbled over
> the uclinux-any ones (added as part of #455501), where I noticed the
> µCLinux fork got merged into mainline Linux in 2.5.46, and then
> several of the no-MMU ports got removed from there more recently.

I must admit that I haven't really used uClinux, or rather any MMUless 
architecture in ages, and the company that I originally wrote this for 
(and which did indeed run an internal Debian mirror with packages for a 
big-endian MMUless ARM box running uClinux) has since shut down, so I 
believe there are no users left.

I'm not sure if it's entirely dead or just about to get a resurgence 
because of FPGAs and FPGA SoCs with integrated hard CPUs that are 
gaining in popularity.

On the pure FPGA side, my expectation is that if it runs Linux, it will 
have an MMU.

The major commercial soft CPUs, Microblaze and NiosII, have MMU designs 
with very little overhead (basically, a TLB and a processor mode for the 
TLB miss handler to run in), so there is little incentive to run MMUless.

RISC-V, ARM and SPARC implementations for FPGAs might be interesting to 
run MMUless (because their MMU interface standards take a lot of 
resources to implement), but I'm not aware of anyone actually doing that.

On the SoC side, I think most available ICs contain an MMU, and those 
that don't aren't really used with Linux (there are some MMUless 
Cortex-R cores that can address enough memory, but I doubt that's a 
practical concern).

So I think these can be removed.

    Simon

-----BEGIN PGP SIGNATURE-----

iQEzBAEBCgAdFiEEtjuqOJSXmNjSiX3Tfr04e7CZCBEFAmVSGYwACgkQfr04e7CZ
CBGiNgf/VFDSuofxqLCgRdZPzJ3CGiCji87rDosshsRnyNz5cwv+8btaZxiMEfc2
OsDNkqn0lkIILD8hkZ+z+B9hWrkTMnI7jF30lRxbECRRRARvCOXIWM6saBTQXB0S
yJZzQdtMJPJCE6JnKulVM5CkJRvEsj7eLVCiH2TwiimtTGFkMrLHSLyyxEnF/L4v
8HL4uuOqbPfCMldC8eRkVrcXphdOYNSoHQ9+6pHtj6KVvztvW9kUHh7vFZ4FDcvG
nzdgK1yecTmvFI2cE2cagZpIVBtOyuQsRc0HxggdoMlJS9kIHm0xOxUHdUAHu+Vr
jf+eB8sroqcL5Px8CSjSs98zRmX5tQ==
=CUcU
-----END PGP SIGNATURE-----