"atsamv" BSP legacy network driver status

[Christian Mauderer]

Hello Peter,

On 28/01/2020 22:37, dufault at hda.com wrote:
> 
>> On Jan 28, 2020, at 04:46 , Christian Mauderer <christian.mauderer at embedded-brains.de> wrote:
>>
>> Before our customers migrated to libbsd (to get some of the features
>> there) the driver in legacy worked. But that is a few years back.
>> Currently I only know of applications using the libbsd driver.
>>
> 
> How are you linking the libbsd code?  Where do you run the code from?

May I start with a counter-question? Are you using an evaluation board
or some custom one? Which chip variant are you using? All projects that
I have been involved used one of the bigger chips (SAME70 or SAMV71).

> 
> The application I'm testing doesn't fit in the internal SRAM provided by the default "linkcmds" in the libbsd case, partly because libbsd is bigger and partly because when I build for "libbsd" it needs "libblock".
>
That depends on the project. One project where I can give you quite open
information is GRiSP. That project is an evaluation platform for using
Erlang on RTEMS. We did most of the initial the RTEMS stuff for it. You
can find the basic RTEMS software here:

https://github.com/grisp/grisp-software

In this project we have a bootloader in the internal flash with some
stuff in an SDRAM. See the linker command file for that:

https://github.com/grisp/grisp-software/blob/master/grisp-bootloader/linkcmds.bootloader

The bootloader doesn't have network support (I removed quite some bits
with the "slim-down.h" file) but it uses libbsd for the SD card. It then
starts a bigger RTEMS application from the SD card. That application
uses libbsd for USB and WLAN. The application uses linkcmds.sdram from
RTEMS.

> It fits if I use "linkcmds.sdram", but then I can't run it because the SDRAM must not be set up properly at reset, I guess I'd need to come up with something using "openocd" that will set up the SDRAM before starting the program.
> 
> I then tried putting just REGION_START in internal flash but it fails when it jump through a trampoline to "system_init_flash" which was still in the SDRAM.
> 
> Then I tried using "linkcmds.qspiflash" but the program didn't fit again since more space was required in the internal SRAM.
> 

We have another project where QSPI is used. I can't give you all details
but some basic information are possible:

This project starts a Bootloader from the internal flash. The bootloader
would then start an application from QSPI XIP area. But it can also use
libbsd for networking. The linkcmds for the bootloader look like follows:

````````
INCLUDE linkcmds.memory

REGION_ALIAS ("REGION_START", INTFLASH);
REGION_ALIAS ("REGION_VECTOR", INTSRAM);
REGION_ALIAS ("REGION_TEXT", INTFLASH);
REGION_ALIAS ("REGION_TEXT_LOAD", INTFLASH);
REGION_ALIAS ("REGION_RODATA", INTFLASH);
REGION_ALIAS ("REGION_RODATA_LOAD", INTFLASH);
REGION_ALIAS ("REGION_DATA", SDRAM);
REGION_ALIAS ("REGION_DATA_LOAD", INTFLASH);
REGION_ALIAS ("REGION_FAST_TEXT", ITCM);
REGION_ALIAS ("REGION_FAST_TEXT_LOAD", INTFLASH);
REGION_ALIAS ("REGION_FAST_DATA", DTCM);
REGION_ALIAS ("REGION_FAST_DATA_LOAD", INTFLASH);
REGION_ALIAS ("REGION_BSS", SDRAM);
REGION_ALIAS ("REGION_WORK", SDRAM);
REGION_ALIAS ("REGION_STACK", SDRAM);
REGION_ALIAS ("REGION_NOCACHE", NOCACHE);
REGION_ALIAS ("REGION_NOCACHE_LOAD", INTFLASH);

INCLUDE linkcmds.armv7m
````````

For the application that is put into QSPIFLASH it's the following:

````````
INCLUDE linkcmds.memory

REGION_ALIAS ("REGION_START", QSPIFLASH);
REGION_ALIAS ("REGION_VECTOR", INTSRAM);
REGION_ALIAS ("REGION_TEXT", QSPIFLASH);
REGION_ALIAS ("REGION_TEXT_LOAD", QSPIFLASH);
REGION_ALIAS ("REGION_RODATA", QSPIFLASH);
REGION_ALIAS ("REGION_RODATA_LOAD", QSPIFLASH);
REGION_ALIAS ("REGION_DATA", SDRAM);
REGION_ALIAS ("REGION_DATA_LOAD", QSPIFLASH);
REGION_ALIAS ("REGION_FAST_TEXT", ITCM);
REGION_ALIAS ("REGION_FAST_TEXT_LOAD", QSPIFLASH);
REGION_ALIAS ("REGION_FAST_DATA", DTCM);
REGION_ALIAS ("REGION_FAST_DATA_LOAD", QSPIFLASH);
REGION_ALIAS ("REGION_BSS", SDRAM);
REGION_ALIAS ("REGION_WORK", SDRAM);
REGION_ALIAS ("REGION_STACK", SDRAM);
REGION_ALIAS ("REGION_NOCACHE", NOCACHE);
REGION_ALIAS ("REGION_NOCACHE_LOAD", SDRAM);

INCLUDE linkcmds.armv7m
````````

I hope that helps.

Best regards

Christian

> I need to:
> - reduce the size by figuring out how to get rid of "libblock" (it isn't needed in the non libbsd case);
> - figure out how to set things up so that "openocd" works using the SDRAM;
> - or relocate everything needed prior to initializing SDRAM to be in the internal flash.
>  
> This is still an evaluation so I only want to see it run.
> 
> Peter
> -----------------
> Peter Dufault
> HD Associates, Inc.      Software and System Engineering
> 
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> 

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