Re: RPI4 (8GB) + UEFI -> bricked?

[Jason Thorpe <thorpej%me.com@localhost>]

> On Aug 21, 2021, at 2:13 AM, Tobias Nygren <tnn%netbsd.org@localhost> wrote:
> 
> On Fri, 20 Aug 2021 19:05:26 -0700
> Jason Thorpe <thorpej%me.com@localhost> wrote:
> 
>> Hey folks.
>> 
>> Trying to get an RPI4 8GB model I picked up a while ago running with the RPI4 UEFI firmware.
>> 
>> Download Jared's Generic 64-bit images, wrote it to an SD card, then followed the instructions here:
>> 
>> 	https://github.com/pftf/RPi4/blob/master/Readme.md
>> 
>> using the v1.29 release, and also performed the EEPROM update as recommended:
>> 
>> 	https://github.com/raspberrypi/rpi-eeprom/releases
>> 
>> What results is the colored square and 7 blinks.  So, I tried writing a fresh image onto SD card. Behavior was different, at least!  I guess it was the low-level loader ... VIC-20-like text informing me that start4.elf was not compatible that that I needed to update the firmware.
>> 
>> So, anyway, I guess the device is not TOTALLY bricked, but I'm not sure how to back out of this corner. Anybody have any ideas here?
> 
> This page describes the boot loader details:
> 
> https://www.raspberrypi.org/documentation/computers/raspberry-pi.html#raspberry-pi-4-boot-flow

Yes. I've read that and I'm a little stumped as to what might be going wrong.

> First thing to try is to make a new "recovery.bin" EEPROM recovery SD
> card. I would try the official "Raspberry Pi Imager" tool to make sure
> the image is correct. If it still fails the SPI chip might be damaged
> as there is not much else that can go wrong.

I already successfully updated the SPI EEPROM, based on this recommendation from the RPI4 UEFI installation notes:

<quote>
Note: Booting from USB or from ESP requires a recent-enough version of the Pi EEPROM (as well as a recent version of the UEFI firmware). If you are using the latest UEFI firmware and find that booting from USB or from ESP doesn't work, please visit https://github.com/raspberrypi/rpi-eeprom/releases to update your EEPROM.
</quote>

I updated it because I couldn't remember when exactly I bought the Pi 4 (it's been sitting in the roundtuit pile for quite some time :-)

The first stage loader (presumably in mask ROM) is able to load the second stage loader (i.e. "VIC-20 mode" :-) from SPI just fine.  If I remove start4.elf from the ESP then I can watch the second stage loader cycle through the boot order:

	https://share.icloud.com/photos/07VV-jR8vYTJSBgkUJx5WI5KQ

So it seems that it's the code in start4.elf that's going off the rails, and I'm just using the one that came with the UEFI bundle.

-- thorpej