[SOLVED] DE10-Nano custom image - Where is U-boot? How is this working?

1

I built an image that works on my DE10-Nano. U-Boot shows the version as 2020.04:

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U-Boot SPL 2020.04 (Jul 07 2020 - 06:35:21 +0000)
Trying to boot from MMC1

U-Boot 2020.04 (Jul 07 2020 - 06:35:21 +0000)

CPU:   Altera SoCFPGA Platform
FPGA:  Altera Cyclone V, SE/A6 or SX/C6 or ST/D6, version 0x0
BOOT:  SD/MMC Internal Transceiver (3.0V)
       Watchdog enabled
DRAM:  1 GiB
MMC:   dwmmc0@ff704000: 0
Loading Environment from MMC... *** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Model: Terasic DE10-Nano
Net:
Error: ethernet@ff702000 address not set.
No ethernet found.

Hit any key to stop autoboot:  0
=>

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But looking in the FAT partition, there is no u-boot.img. So how is this working?

Screenshot from 2020-09-10 00-13-06
Screenshot from 2020-09-10 00-13-06705×304 42.1 KB

2

Okay - after studying this page one more time, it seems that the u-boot is no longer present in the fat partition. Instead, it appears to be combined with the SPL in a binary format and copied as an executable into the binary partition of the sd card image.