Is there a way to make the TX1 automatically boot at power-on? With the dev board I have to press the power button to boot it and that won’t work for my application. When I press the power button, the first few messages on the serial terminal are:
[0000.199] [TegraBoot] (version 24.00.2015.42-mobile-f8f04b74)
[0000.205] Processing in cold boot mode Bootloader 2
[0000.209] A02 Bootrom Patch rev = 31
[0000.213] Power-up reason: on button
Which makes me think that something needs to be modified in nvtboot, but that’s where I’m at a loss because it seems to be at a lower level than the documentation describes. Can anyone help point me in the right direction?
I just got the answer to this question which I can share with you. The latest version of the OEM Product Design Guide was released on July 14th, 2016 and has a new section for Auto-Power-On support. It is section 3.8 and begins on page 16. You might not like the answers however.
There are 3 ways detailed in the guide and all of them require hardware modifications to support hands-free startup when power is applied.
Option 1 is to use a microcontroller (the assumption being you may already have one in your design). This method has you waiting the prescribed delay of >300ms before pulling down on the POWER_BTN# or CHARGER_PRSNT# lines for the prescribed time (different for each pin).
Option 2 is to use a supervisor IC and set it to delay the pull down of CHARGER_PRSNT# line. A reference circuit design is provided.
Option 3 is to use the discrete circuit provided in the guide to cause the delay.
Any of them will work. You just have to decide how you want to implement. I did not find any kind of BIOS type setting which would do this from software.
That is unfortunate. So what it comes down to is that you must press the button to boot. These workarounds basically just electronically press the button for you at power-on. Looks like I’ll have to re-spin my carrier board.