Soft Reboot

[matthieugaboria]

Hello,
I am currently on a project where I have to boot on an SPI flash device.

The context is the following :

- The card I am using (Cosmic board from Phytec) is set to boot from SD card.

- We don't want to change the eFuse.

After giving a shot to non working solutions (writing SPI boot config to eFuse shadow register and jumping to 0x0), I found the functionnality i want on iMX6.

Does  the Vybrid support the "magic" watchdog boot like the i.MX6 disussed here ?

If Yes, where is the magic bit (SRC_GPR10[28] in case of iMX6) and which register is holding the boot config (SRC_GPR9 in case of iMX6).

Any helpful piece of information is welcomed.

[matthieugaboria · Accepted solution]

Hello,

I found the answer to my question !!

The boot mode used is "Watchdog Reset Boot Mode" mentioned section 19.4.8 of VYBRIDRM (never properly documented anywhere).

The addresses of the registers used can be found in the VYBRIDSRM section 4.3 .

It is properly working now.

Thank you.

[naoumgitnik]

Dear Matthieu,

I am glad you fixed your issue!

Since a customer is the best judge for our work, may you do us a favor and provide some hints on how you would like us to modify text of the mentioned VYBRIDRM section 19.4.8 and VYBRIDSRM section 4.3.

We would highly appreciate this guidance based on your good will!

Thanks in advance, Naoum Gitnik.

[matthieugaboria]

Dear Naoum,

I think the following improvements could be made in the documentation.

1st : section 19.4.8 in VYBRIDRM. The hyperlink on "Watchdog Reset Boot Mode" could lead to a note which says "Details about Watchdog Rest Boot Mode can be found in VYBRIDSRM section TBD" instead of nowhere. (TBD stands for To Be Determined since I am not the writer :-)

2nd : in VYBRIDSRM. There could be a little section speaking about the possibility to use other boot parameters after a Watchdog Reset (until next Power On Reset). This section could be a sub section of System Boot (section 6). It would give details about which registers to use and what to put in them.

I was a pleasure to give you my opinion and maybe contribute to a better documentation.

Thanks

[naoumgitnik]

Dear Matthieu ,

I formulated the Vybrid Reference Manual future change quite easily and am currently working on the Security Reference Manual one. While doing that, I am comparing it to the i.MX6 Security Reference Manual and having difficulties since it looks like the registers are named/numbered differently, and my specialty is Vybrid, not i.MX6. May you do me a favor again, please, and briefly mention which specific Vybrid's registers are involved in your case? - Most likely they have the same names as for i.MX6; if not, do you remember, what i.MX6's ones do they correspond to, please?

Again, I realize it is only based on your good will, and your help will be highly appreciated, and not only by me but all the Community members who will follow in your footsteps in the future!

Thanks in advance, Naoum Gitnik.

[matthieugaboria]

Dear Naoum,
The specific Vybrid registers involved in my case are mentioned section 4.3 of the Vybrid Security Reference Manual.
They are named SRC_ROM3 and SRC_ROM4.
The procedure is to write a bit in SRC_ROM4[28] to enable the functionality (Watchdog Reset Boot Mode) and then to write inside SRC_ROM3 what should normally be inside SRC_SBMR1 (the boot configuration, normally sampled from fuses).

Matthieu GABORIAU

ps : the functionality is not detailed at all in the iMX6 Reference Manual or Security Reference Manual.

[naoumgitnik]

Thanks a lot, Matthieu!

/Naoum G.

[naoumgitnik]

Dear Matthieu,

Thanks a lot for your help!

I will "digest” this information and think how to formulate it for our technical writers to be added into the documentation.

Sincerely, Naoum Gitnik.

[billpringlemeir]

I think GPR  and ROM are being used interchangeably in the current documentation.  That is probably just a consistency change that would make this easier to understand.  Look at the ROM detailed descriptions.  I guess that other documents use GPR.  I would just put a reference that the ROM are also known as GPR; if this is in fact the case.  As a user, I do PDF searches to look through all the information on a particular topic.  Changing the names makes it hard to find all the relevant information in all of the different documents.  Any rosetta stone information is helpful.

[naoumgitnik]

Dear Bill,

I am currently working on the documentation, and I am afraid these 2 things are not the same… will comment more if learn more…

/Naoum G.

[timesyssupport]

Hello,

We have made an inquiry with Phytec about booting from SPI on the Cosmic board. We will update once we have heard back from them.

Thanks,

Timesys Support

[karina_valencia]

timesyssupport can you attend this case?