Re: Patches for the eCos 2.0 branch

[Nick Garnett <nickg at ecoscentric dot com>]

Gary Thomas <gary at mlbassoc dot com> writes:

> 
> Actually, I tried to make it such that a dependency does not exist
> (note the most recent version which this patch reflects does try 
> and work properly even without an updated RedBoot).  I may have
> missed the mark, but I did try.
> 

It certainly caused me a bit of head scratching when I tried running
on an Adder board with an old RedBoot yesterday. Fortunately I
remembered your change and updating the Adder's RedBoot fixed it.

The problem appeared to be that *(CYGHWR_HAL_VSR_TABLE + 0x1F0)
contained 0xFFFF, resulting in _mpc8xx_allocBd() starting again from
QUICC_BD_BASE and overwriting RedBoot's stuff for the serial device.

The effect I saw was that halfway through initializing the rx buffer
descriptors, the serial device went haywire.

I'm not sure how it is possible to make this code backward compatible,
since without the value in (CYGHWR_HAL_VSR_TABLE + 0x1F0), eCos has no
way of knowing where in the DPRAM it can make allocations.


-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts