How to read PBL preamble and RCW header in u-boot

[vishnu_motghare]

In the u-boot source code there is RCW CFG file u-boot/board/freescale/ls1021atwr/ls102xa_rcw_sd_qspi.cfg

#PBL preamble and RCW header
aa55aa55 01ee0100

#disable IFC, enable QSPI and DSPI
0608000c 00000000 00000000 00000000
30000000 00007900 60040a00 21046000
00000000 00000000 00000000 20000000
20024800 881b7340 00000000 00000000

How to read these values & what are their meaning? How these hex values are generated? If I want to change something e.g. disable QSPI how to do it? Any references where I can read & understand the meaning of these hex values?

[mrudangshelat-13 · Accepted solution]

Hi @vishnu_motghare 

Refer to QCVS PBL Tool User Guide:

https://www.nxp.com/docs/en/user-guide/QCVS_PBL_User_Guide.pdf

Refer to the RCW field definitions section in the LS1021A reference manual, which describes the function of individual bits of the 512-bit (64-byte) RCW data structure.

Regards,

Mrudang Shelat

[vishnu_motghare]

Hi @mrudangshelat-13
Thanks for your reply. The document shared by you really helped. We have been stuck with a problem where we are not able to boot from qspi flash. We have two variants of flash from Macronix MX66L2G45G (256MB) & MX66LM1G45G (128 MB). MX66L2G45G (256MB) flash supports Singal I/O, Dula I/O & Quad I/O & It has Quad Peripheral Interface (QPI) and we are able to boot the ls1021atwr custom board with it from flash. Whereas MX66LM1G45G (128 MB) flash supports only Singal I/O & OCTA I/O & It has Octa Peripheral Interface (OPI) but we are not able to boot from this flash.
So the question here is does PBL only supports Quad I/O because that's the only difference between these two flashes?