Re: [ECOS] AT91sam7a guidance in porting

[Andrew Lunn <andrew at lunn dot ch>]

On Fri, Nov 30, 2007 at 10:56:16AM +0200, Meiring, H, Mnr <meiring@sun.ac.za> wrote:
> 
> Hi all,
> 
> I am planning to work most of the next month on the porting of the sam7a2 uC and drivers but would appreciate it if someone can guide me through the process please.
> 
> Current Project status: 
> 
> I copied at91sam7s platform/variant and renamed to at91sam7a and adjusted the ecos.db to make a target at91sam7a2 visible consisting only of the basic hal packages. 
> CYGPKG_HAL_ARM
> CYGPKG_HAL_ARM_AT91
> CYGPKG_HAL_ARM_AT91SAM7A
> I also adjusted the memory layout files to only run from ram.

I've not looked at the SAM7A2 much. Is it sufficiently different from
the SAM7 what it needs a whole new platform & variant? If it fits, i
would suggest extending the SAM7S package to cover the A2 as well.

> When using my sam-ice jtag device with gdb server and insight,
> redboot runs successfully, (according to me) I can do mfill, dump
> etc for the whole memory range over the usart.

I would run clocktruth and tm_basic, the kernel test programs. If
clock truth works correctly it means timers are O.K. and basic
interrupt handling is working. tm_basic is a good all round test.
Then just pick a few random tests and see if they work. You could
systematically run all the tests, but that takes a while.

> What next? I suppose I need to add a flash driver for the flash
> chips iplemented, but where to start.

Does the A2 have on-chip flash like the SAM7S? If so, it should be
very easy to make the existing driver work. Just add the cpu id.  If
it is an external chip, more work is needed. You need the generic
flash driver for the chip you have, plus a hardware specific driver
for your particular platform. This configures the generic driver for
your setup. Look at the other targets for examples.

What comes after that depends on what you want to do with the
hardware. Get the SPI working? Write an I2C driver etc...

          Andrew

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