[B4860 SPIFLASH BOOT ROM] Help to understand booting process from SPI

[canvanquyen]

Dear all,

As I know, Booting from SPI flash. First of  all, device will sample cfg_rcw_src[0:8]( SW1.0:7 & SW2.1) to determine where it starts to get RCW & PBI cmd.

If cfg_rcw_src[0:8] selected for SPI FLASH, B4860 will load RCW to RCWSRn , PBI to CCSR, SPL to SDRAM.

As I know :

In PBI cmd that enable SPI interface ("board/freescale/b4860qds/b4_pbi.cfg").

#Configure SPI controller

09110000 80000403

09110020 2d170008

09110024 00100008

09110028 00100008

0911002c 00100008

My question is :

How B4860 can load RCW, PBI to RCWSR and CCSR memory if SPI controller did not enable?

Could someone help me understand this process in B4860.

Thank you very much!

[sinanakman · Accepted solution]

Hi Can

PBL (Pre-boot Loader)  initializes the controller. The

chapter "Pre-Boot Loader (PBL)" in your B4860 Reference

Manual explains more in detail which peripherals it initializes

to load RCW and boot from. Please refer to that chapter

for more detailed information.

Regards

Sinan Akman

[canvanquyen]

Hi, Sinan Akman,

Thanks for your answer.

I found that in the reference.

5.3 PBL Modes of Operation
• Load both RCW and pre-boot initialization commands from individual interface.
• Load RCW only.
• Load pre-boot initialization commands only if default RCW is to be used.

So that we need to re-initialize SPI again in PBI command.

Is that correct?

Thanks.

[sinanakman]

Hi Can

You don't need to re-initialize SPI, but as listed on

your PBI :

09110020 2d170008

09110024 00100008

09110028 00100008

0911002c 00100008

It sets the mod register for

the underlying hardware.

PBL initializes SPI controller so

that it can access it for RCW, PBI etc.

Then if there is PBI, it executes

it to set/modify registers for the platform

design.

Regards

Sinan Akman

[canvanquyen]

Hi Sinan Akman,

Thanks for your help :smileyhappy:

Regards,

Quyen.