Re: HOWTO: USB boot on 8 GB RPi4 with no SD card

[Paul Mather <bsd-lists%gromit.dlib.vt.edu@localhost>]

On Jul 28, 2020, at 2:31 PM, Ted Spradley <tsprad%talent-free-studios.com@localhost> wrote:

> On Mon, 27 Jul 2020 15:06:29 -0700
> Michael Cheponis <michael.cheponis%gmail.com@localhost> wrote:
> 
>> The SD card is a nasty reliability issue with the RPi.  Now, it's possible
>> to do away with the SD card entirely.  Thanks to Paul Mather for doing this
>> first.
>> 
>> Here's the recipe (it's much easier than this list makes it seem):
> [...]
>> I hope this is a fairly accurate write-up.  If you can't get it to work, I
>> can probably help.
> 
> Thank you so much for this neat, simple write-up. Unfortunately, it doesn't work for me.
> 
> When I try to boot my RPi4 without an SDcard it fails with "SD card not detected" after "bootloader: a5e1b95f Apr 16 2020"
> 
> Running Raspbian I get:
> 
> pi@raspi4:~ $ sudo rpi-eeprom-update
> BCM2711 detected
> Dedicated VL805 EEPROM detected
> BOOTLOADER: up-to-date
> CURRENT: Thu 16 Apr 2020 05:11:26 PM UTC (1587057086)
> LATEST: Thu 16 Apr 2020 05:11:26 PM UTC (1587057086)
>  FW DIR: /lib/firmware/raspberrypi/bootloader/critical
>  VL805: up-to-date
>  CURRENT: 000137ad
>   LATEST: 000137ad
> pi@raspi4:~ $  
> 
> Is that the right firmware to make this work? Or have I screwed up making my USB memstick?


The April firmware is not recent enough.  You need to change to the "stable" channel to get an EEPROM firmware version that will boot without the SD card present.  You are using the "critical" channel.  (See "Changing the firmware release" in https://www.raspberrypi.org/documentation/hardware/raspberrypi/booteeprom.md)

Note that the BOOT_ORDER EEPROM default has changed in the current stable firmware.  I would recommend using "-d" with rpi-eeprom-update to ensure the defaults are applied, rather than the existing settings.  See https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711_bootloader_config.md for details.  (The default has changed from 0x1 to 0xf41.  The latter will mean the EEPROM will attempt a USB MSD boot [4] if a SD card boot is not successful.)

Cheers,

Paul.