On Thursday, March 17, 2011 02:40:01 Magnus Damm wrote:
> This is the first public release of SH Core Linux, version 20110317.
> 
> SH Core Linux brings the Linux to the SH core included in sh7372 -
> running in parallel with the ARM core.
> 
> Many modern SoCs contain multiple CPU cores in asymmetric
> multiprocessing configurations. These asymmetric CPU configurations
> often run multiple operating system instances; sometimes multiple
> instances of Linux and sometimes Linux on the main CPU and some
> customized software on the other CPU cores. Asymmetric CPU
> configurations are different from symmetric multiprocessing
> configurations which make use of a single Linux kernel together with
> SMP to support multiple processor cores. To make things even more
> complicated, come SoCs are configured to have some CPU cores operating
> in SMP mode, and others in AMP.

interesting.  we've been banging on similar issues with multiple Blackfins.  
we've got an ICC (inter core communication) driver going atm.  but the 
protocol isnt limited to Blackfins ... we've made sure to design it so that 
any other processor type can work, as well as any operating system.

> This SH Core Linux prototype is written for the sh7372 SoC from
> Renesas. The sh7372 contains one ARM Cortex-A8 and one SH4AL-DSP core.
> This release includes all that is needed to run two instances of
> Linux; one on the ARM core and one on the SH core. The ARM core is the
> main SoC processor which runs a user space program to control the SH
> core. The SH core does not make use of any special hardware except a
> mailbox interface where Virtio serves as a communication link.

so this implementation isnt limited to Linux right ?

i think TI has been doing their own thing too ?  but they dont usually try 
hard to push back to mainline ...

and then there's MCAPI ...

i wonder if there's some way we can centralize/focus efforts on the Linux side 
so each SoC vendor doesnt keep coming up with its own magic sauce to glue 
worlds together.  i really dont see this as being a useful area for everyone 
to "innovate" on their own.  the advantage to being the first one into 
mainline is that everyone else will have to migrate to it :).

perhaps start a list on vger.kernel.org and a wiki on wiki.kernel.org ?
-mike