rtems from TMS570 SDRAM or INTRAM

[Pavel Pisa]

Hello Nikolay,

On Monday 20 of March 2017 15:16:41 Nikolay Komashinskiy wrote:
> Thank you for your reply. I will have the ability to work with a board in a
> month. My target board is TMS570LC43x LaunchPad.
> But I need advice - what can be implemented during the GSoC by me?
> Personally, I am interested in SPI and Serial interfaces, because many
> peripheral work with them.

serial interface should be supported, TMS570LS3137 UARTs support should
be compatible with TMS570LC43x (I hope). The SPI worth to be
implemented for both targets, we have many SPI peripherals
working in our non-RTEMS TMS570 project so that board can be used
for testing. TMS570 SPI driver conforming actually adopted Linux API
on RTEMS would be nice.

> Also, i2c and GPIO are used by me.

Some example of RTEMS style defined GPIO functions can be found
in Raspberry Pi BSP

https://git.rtems.org/rtems/tree/c/src/lib/libbsp/arm/raspberrypi/gpio/rpi-gpio.c

The bank parameter is necessary on TMS570 because there is large
number of GPIO groups each with same set of the control registers.

I2C would be nice too.

> I am interested in Ethernet protocol itself (want to know more how
> it works). And that is strange for me that BBB has IEEE 1588v2 support and
> TMS570 doesn't.

There quite lot of work even on base ETHERNET/LwIP integrations still.

I am not sure how much work can fit in GSoC. It depends mainly
on the amount of work required for the board bring-up.
If you have working JTAG debugger from the startup then things
are much easier. You can use CCS for debugging even of RTEMS
applications even that fully open source toolchain is more preferred
by me.

The LaunchPad kit has disadvantage that there is no SDRAM
so you need to flash application for each iteration.
That is quite time consuming and even CSS seems to be considerably
slower (at least on GNU/Linux system) than OpenOCD. But making OpenOCD
to work on the given chip variant can be quite large project in itself.
The other disadvantage of missing SDRAM is that TMS570 code (not much
smaller data) Flash has limited erase cycles declared. Only 1000
are guaranteed. I expect that at a normal conditions (temperature etc.)
the Flash would sustain much more cycles functional. But it is limiting
factor as well. On the full HDK there is a SDRAM which requires
much more complex setup but then it makes furher development
easier.

Best wishes,

Pavel