Picozed + FMC2 booting Petalinux 2020.1 from QSPI/eMMC

Are there any instructions anywhere for booting Petalinux 2020.1 on a picozed from QSPI and kernel in on-board eMMC?

I've followed various older instructions for building an appropriate BOOT.BIN file and writing that to the QSPI Flash and copying the image.ub file to the onboard eMMC, but I still can't get petalinux to boot up.

When I power up with the switches set to boot from QSPI, the FPGA code apparently gets loaded OK, ,since the blue "FPGA DOne" LED comes on, but the next stages of booting fail.
First, U-Boot detects the QSPI flash, but then gives an error about "bad CRC;

U-Boot 2020.01 (Oct 30 2020 - 12:46:02 +0000)

CPU: Zynq 7z020

Silicon: v3.1

DRAM: ECC disabled 1 GiB

Flash: 0 Bytes

NAND: 0 MiB

MMC: mmc@e0100000: 0, mmc@e0101000: 1

Loading Environment from SPI Flash... SF: Detected n25q128a13 with page size 256 Bytes, erase size 4 KiB, total 16 MiB

*** Warning - bad CRC, using default environment

Continuing on, it gives several 'Wrong image format for for "source" command' errors.

In: serial@e0001000
Out: serial@e0001000

Err: serial@e0001000

Net:

ZYNQ GEM: e000b000, mdio bus e000b000, phyaddr 0, interface rgmii-id

Warning: ethernet@e000b000 using MAC address from DT

eth0: ethernet@e000b000

Hit any key to stop autoboot: 0

SF: Detected n25q128a13 with page size 256 Bytes, erase size 4 KiB, total 16 MiB

device 0 offset 0xfc0000, size 0x40000

SF: 262144 bytes @ 0xfc0000 Read: OK

## Executing script at 03000000

Wrong image format for "source" command

SCRIPT FAILED: continuing...

## Executing script at 03000000

Wrong image format for "source" command

SCRIPT FAILED: continuing...

MMC: no card present

switch to partitions #0, OK

mmc1(part 0) is current device

Scanning mmc 1:1...

SF: Detected n25q128a13 with page size 256 Bytes, erase size 4 KiB, total 16 MiB

device 0 offset 0xfc0000, size 0x40000

SF: 262144 bytes @ 0xfc0000 Read: OK

## Executing script at 03000000

Wrong image format for "source" command

SCRIPT FAILED: continuing...

no devices available

SCRIPT FAILED: continuing...

## Executing script at 03000000

Wrong image format for "source" command

SCRIPT FAILED: continuing...

Still it continues, now trying to read an image via TFTP. Eventually it gives up, leaving me at the bootloader prompt:

Starting USB...

Bus usb@e0002000: USB EHCI 1.00

scanning bus usb@e0002000 for devices... 1 USB Device(s) found

scanning usb for storage devices... 0 Storage Device(s) found

Device 0: unknown device

Device 1: unknown device

BOOTP broadcast 1

BOOTP broadcast 2

BOOTP broadcast 3

DHCP client bound to address 192.168.2.100 (1149 ms)

*** ERROR: `serverip' not set

Cannot autoload with TFTPGET

missing environment variable: pxeuuid