* Reset Ethernet MAC + PHY if final boot mode is not network boot
See: Kernel warning and network failure when attempting to use
the network after bootloader times out. #144
* Improve handling of multiple bootable USB devices and remove USB_MSD_BOOT_MAX_RETRIES
* Resolve: No DHCPACK with DHCP relay agent #58
* Toggle USB root hub port power for 200ms on the first USB MSD boot attempt
See: Bootloader can't boot via USB-HDD after system reboot #151
* Update bootloader handover to support uart_2ndstage - requires a newer
start.elf firmware which will be via rpi-update.
* Assert PCIe fundamental reset if the final bootmode was not USB-MSD
because the OS might not do this before starting XHCI.
* Resolve: Unable to boot from USB MSD - Seagate 5Tb HDD backup drive #139
* Increase USB MSD timeout from 10 to 20 seconds.
* Max retries now default to zero because the default BOOT_ORDER includes
restart (0xf). Therefore, each boot-mode is now tried once before moving
to the next mode. The retries mechanism is largely redudant now that
the loop/restart mode exists.
* If TFTP fails and network boot retries > 0 then wait 5 seconds before
retrying to avoid overloading a misconfigured TFTP server.
* Map undefined boot-modes in BOOT_ORDER to SD (0x1) instead of stopping.
* Add missing pieeprom-2020-05-28
* Resolve: USB boot fails if the GPT contains no basic data or EFI partitions #130
* Resolve: Fix default BOOT_ORDER in mass storage beta #129
* Resolve: Add support for booting from a "superfloppy" disk #120
* Resolve: USB MSD timeout message - incorrect units #131
* Resolve: Recognize efi partition (0xef) as a valid boot #126
* The HDMI diagnostics screen now displays the most significant bytes of the SHA-256 of the config.txt file.
Now that 2020-04-16 has been released and appears to be stable move
the older binaries to and old (deprecated) directory. There's no
need to include old beta binaries in OS packages.
* Fix uart_2ndstage in the recovery.bin
* Fix missing watchdog reset if only the VL805 image is updated.
* Fix detection of VL805 EEPROM in recovery mode.
* If no EEPROM images are present then recovery.bin now renames
itself and reboots instead of treating this as an error.
Tweak analog settings for possible improvements to PCIe reliability
but unlikely to make a difference for most users and requires
corresponding changes in start.elf (future rpi-update)
