MPC82xx -- DPRAM1

[Dan Malek]

On Nov 15, 2004, at 11:10 AM, morten.banzon at axxessit.no wrote:

> I am using 2.6.9 for a mpc8280 project, and am having trouble using 
> dpram1
> from offset zero, which I need for a mcc hdlc driver.

Why does it have to start at zero?

>  In the file include/asm-ppc/cpm2.h there is a constant 
> CPM_DATAONLY_BASE
> In the same file the code comment say that the first 128 bytes are used
> for SMC1 and SMC2.

Yes, it is.

> When I examine the smc (cpm_uart) driver i do not find any reference to
> this region of the dpram1.

It's there somewhere, hardcoded with values 0, then sizeof() something 
is
probably added to it.

> I have replaced the calls to cpm_dpalloc with cpm_dpalloc_fixed and an
> adress way up in the dpram1 region.

Very bad idea.

> My question is; do you know which code is using the dpram1 addresses 
> below
> CPM_DATAONLY_BASE ?

The SMC1 and SMC2 peripherals, just like the comment says.

> This region must be used by something (smc ?), because when I clear 
> from
> offset 0x00 to 0x80 the serial port stop responding.

Yep.


	-- Dan