Re: TO ULF SAMUELSSON: Why "sigh" at uCLinux?

C. J. Clegg wrote:

Good afternoon, Ulf.

Back in November of 2007, in comp.arch.embedded, you wrote:

"I see as many ARM9 users as ARM7 users today and neither the CM3 or
the uC3k will meet the performance of the ARM9 and neither will run
Linux/WinCE. - uCLinux? ...sigh!"

I've only started reading about uCLinux over the last couple of days
but I was wondering why you "sigh" at it.

I'm told that the Atmel AVR32UC3A/B (and their associated eval boards,
the EVK1100/1) cannot run Linux because the processor doesn't have an
MMU... hence something like the AVR32-AP7, at a minimum, is needed.

On the other hand, uCLinux is specifically designed to run on
processors without MMUs. So, any reason why uCLinux cannot (or should
not) run on the AVR32UCA/B?

Certainly uCLinux has its limitations but if it's the only flavor of
Linux that will run on processors without an MMU, and the lack of MMU
is the reason why the UC3x can't run Linux, then I would think that a
uCLinux port for the UC3x would be welcomed by low-end processor
developers... would it not?

With Linux 2.6 looks like uCLinux is integrated in the main Linux
distribution and (nearly) all API calls are compatible with standard Linux:

http://linuxdevices.com/articles/AT2598317046.html

Looks like the AVR32UC has max 512KB flash and 64KB RAM:

http://www.atmel.com/dyn/resources/prod_documents/32058S.pdf

This means uCLinux can't run on it without external memory, because it
needs 1MB ROM and 200KB RAM:

http://www.linuxdevices.com/articles/AT8482313700.html

With external memory it is possible. One SDRAM chip and one serial flash
chip should work.

--
Frank Buss, fb@xxxxxxxxxxxxx
http://www.frank-buss.de, http://www.it4-systems.de
.

Relevant Pages

  • Re: Impact 8.1 problems=> uClinux rules on MicroBlaze !!!
    ... On the Linux vs windows workstation issue, ... The decision to not support Windows for MicroBlaze uClinux ...
    (comp.arch.fpga)
  • Re: uCLinux on Samsung S3C4510B (ARM7TDMI) based wireless router
    ... serial port or printer port, ... linux or further. ... > router, access point and print server, all at the same time, preferably ... > and openap-ng) options as well as uCLinux. ...
    (comp.os.linux.embedded)
  • Re: best evm for virtex-4 and linux
    ... But that brings up another question: Is it better to go with ucLinux ... > or use the PPC version of linux? ... There are some guides out there on DIY Linux for Xilinx PPC, ... >>shipping with both device and host support drivers for USB ...
    (comp.arch.fpga)
  • Re: TO ULF SAMUELSSON: Why "sigh" at uCLinux?
    ... Good afternoon, Ulf. ... I've only started reading about uCLinux over the last couple of days ... uCLinux could run on any decent processor without an MMU. ... Many applications which runs under Linux will not run under uCLinux, ...
    (comp.arch.embedded)
  • Re: Suggestion needed on Embedded Linux support for my board
    ... That particular ARM chip does not have enough RAM or Flash to support ... Linux or uClinux and the LPC also doesn't have the required MMU for ... lot of external RAM and Flash could be made to run uClinux. ...
    (comp.os.linux.embedded)