[coreboot] Help on setting clock speed in coreboot

Naveed Ghori naveed.ghori at dti.com.au
Tue Jul 12 03:41:37 CEST 2016


We take the pins direct off the E3845 (only really need the tx (pin BD14 (GPIO_S0_SC[57]))). The pins direct are TTL so we had to use a TTL-USB serial port converter.

From: Mayuri Tendulkar [mailto:mayuri.tendulkar at aricent.com]
Sent: Tuesday, 12 July 2016 9:37 AM
To: Naveed Ghori; coreboot
Subject: Re: Help on setting clock speed in coreboot

Thanks. We tried 115200, but it didn't work. We checked TTL levels and tried to match, but no luck.

Are you using PCU UART (same as minnowboard) or anything different?

From: Naveed Ghori [mailto:naveed.ghori at dti.com.au]
Sent: 11 July 2016 18:17
To: Mayuri Tendulkar <mayuri.tendulkar at aricent.com<mailto:mayuri.tendulkar at aricent.com>>; coreboot <coreboot at coreboot.org<mailto:coreboot at coreboot.org>>
Subject: Re: Help on setting clock speed in coreboot

Hi,
Garbage usually means baud rate. Did you try 115200baud?
If you are still getting garbage I would recommend seeing it on the scope and making sure voltage levels are fine. The output by default would be TTL level and may need to be converted.
I have used some TTL (1.8V if I remember correctly (TTL-232RG) to convert the signal so I could read the output.

Cheers,
Naveed

From: coreboot [mailto:coreboot-bounces at coreboot.org] On Behalf Of Mayuri Tendulkar
Sent: Tuesday, 12 July 2016 8:27 AM
To: coreboot
Subject: [coreboot] Help on setting clock speed in coreboot

Hi Team

I have a customized board based on Intel valley island design. Reference design uses Intel Baytrail processor E3825, while my design is using E3845.

I am customizing coreboot for this E3845, but getting just garbage on coreboot, so not able to debug where it is stuck.

When I add memory test as secondary payload, I cd see some operations happening on console but not able to decode it.

Tried with all possible baud rates, but no success. USB and display also not enumerating.

Can you please give some clue? Is it due to different core speed for E3835(1.33GHZ) vs E3845(1.91GHz).

Where is the option to change this in coreboot?

Appreciate your support.

Regards
Mayuri
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.coreboot.org/pipermail/coreboot/attachments/20160712/1ad83596/attachment.html>


More information about the coreboot mailing list