Re: [Xenomai-core] User space drivers on PPC440

[Philippe Gerum <rpm@xenomai.org>]

Steven A. Falco wrote:
> The rt_misc_get_io_region() has the "start" argument as an unsigned 
> long.  On the PPC440, we have a 36-bit address space, where the I/O 
> registers are generally above the 4GB area.  For example, the UART is at 
> address 0x1ef600300.
> 
> The Linux request_region call has "start" typed as a resource_size_t, 
> which is a u64 on the PPC440 (i.e. CONFIG_RESOURCES_64BIT is set even 
> though this is a 23-bit processor).
> 
> Is this something that should be handled by xeno-config?  It could 
> append a CFLAG indicating the size of a resource.

Or use a 64bit long unconditionally, to keep the same kernel-based
implementation, since there is no performance issue for this call. In
any case, we need to fix the API before 2.4 final is out -- which will
also affect the ABI, but it already changed during the 2.4 development
phase anyway.

> 
>     Steve
> 
> 
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-- 
Philippe.