* 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
* 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)
* Option to restrict automatic updates to bootloader and/or vl805
* Change the machine mode output variables
* recovery.bin: Rebuild from Gitlab
* Rename CURRENT_TS and LATEST_TS in machine output
* New beta recovery.bin which can update the VLI EEPROM before
start.elf is loaded. This is the recommended and default method
because no USB devices will be in use at this stage.
* Extend the USE_FLASHROM configuration to use the vl805 tool
to program the VL805 directly.
* Generate SHA256 checksums in .sig files for the bootloader and
and VL805 images. This is required by the new recovery.bin to
guard against corrupted files being flashed to the EEPROM(s).
* Various variable renames to distinguish between the bootloader
and the VL805 images.
Select the recovery.bin to use according to FIRMWARE_RELEASE_STATUS
in order to allow a beta test version of recovery.bin to be provided
without risking breaking the stable version of recovery.bin
