DDR3 via ethernet boot c6670

Hello Taras,

I was struggling with this problem for last two weeks. Here what I can tell you. There is two ways to initialize the DDR3 through Ethernet boot loader. For both of them you need to make a two stage boot loader.

As you know in the Ethernet boot mode the DSP is sending BOOTP packets to the host, which indicates that it is ready to receive a boot table data. So as I understand you already made a bootloader which boot your application through Ethernet to MCMSRAM or L2SRAM. If so the next step is to create such boot table which will initialize the DDR3 and make the DSP generate BOOTP again. So to clarify to put your application .text to the DDR3 you will need two images. Firs init the DDR and second is just your normal application with sections in the DDR3.

I cannot give you mine code of the first stage boot loader but I can tell you how to create your own using existing ources.

1) At this TI example you will find a reboot.c file processors.wiki.ti.com/.../SecondaryBoot_PLLfix.zip.  

2) Actually for simplification you can create a blank CCS project and Add files reboot.c, nysh.cmd, tiboot.h, types.h to it. At this stage it will not build because of chipDelay32 function which declared in the assembler file delay.s. The thing is here that compiler would not see the definition of that function in the delay.s even if you add it to the project. So i made just like this:

void chipDelay32(unsigned int cycleCount)
{
while (cycleCount--) {
asm(" NOP");
}
}

this if pretty much the same as in the assembler file.

3) But it will still not compile :) Next step you need to change the lines at the end of the main in the reboot.c

/* Re-execute the ROM */
romtReInit ();

to the 

fcn = (void(*)(void)) ROMBOOT_REENTRY_ADDRESS;
(*fcn)();

also at the beginning of the main.c you need to add a pointer definition: void(*fcn)(void);

and at the beginning of the reboot.c file add: #define ROMBOOT_REENTRY_ADDRESS             0x20B00008

4) there are 3 scenarios in the reboot.c you need just define the ETH global variable to write to the DEVSTAT register the Ethernet boot mode :

#ifdef ETH
reg = 0x3485;
#endif

*((unsigned int *)0x2620020) = reg;

All this was necessary to obtain the .out file of the first stage bootloader that can be converted to the .hex and so on into boot table. But this image just reset a DSP to generate a BOOTP again. Now you need to add in the main of the reboot.c before the /* Re-execute the ROM */ line three mandatory functions of DDR3 initialization.

This functions are in ascending order: SetDDR3PllConfig(); xmc_setup(); DDR3Init();. The "guts" of that functions are located in the evmc6670.c file located in the {PDK_INSTALL_PATH} packages\ti\platform\evmc6670l\platform_lib\src. So you can call them or call the platform_init() routine (located in platform.c file ) if you want initialize here PHY, main PLL and other stuff. This functions are a part of that routine. I just copied the "guts" of mentioned functions so the code is big and sloppy but fast)).

And the second way is to put this first stage loader to the EEPROM and use IBL, but in my project it was not an options since it was occupied already and it is hard to change the dip switches from Ethernet boot mode.

Hope it will help you if you have any questions regarding the procedure, feel free to ask.

Best Regards,

Pavlo