OpenSystemsDevelopment / usbboot

Update EEPROM, recovery.bin and bootcode4.bin to 2022-04-26

Previously two commits added a fallback fmemopen for OS X/BSD that
didn't support fmemopen, then fixed some of the ifdef logic around it.
Unforunately the logic was backwards, as libc implementations do not
define _POSIX_C_SOURCE in order to advertise features.  Instead the
user defines _POSIX_C_SOURCE to control which definitions are
available.

Check _POSIX_VERSION to see if the libc is new enough to implement
fmemopen.  If it is too old, assume that we're on a BSD compatible
system and use the fallback fmemopen that depends on funopen.
This solves the problem for some environments, but is still incorrect
as it will try to use the fallback even on a system that does not
include funopen.

Fixes: 45c7237 (Fixup for recent firmware inclusion changes (#34))
Fixes: 17f6b01 (Fix cross-platform building)

Add inline comments about boot order

Add no sudo hint

When not signing the configuration (no -k option), there's no
$TMP_CONFIG file and `test -f "$TMP_CONFIG"` is false. The whole line
becomes false and the script exists 1 for `set -e`.

This commit fixes that by moving the test to `if` condition.

Fixes: d1a9a5c659e8 ("beta: Add support for secure-boot - see Readme.md")
Signed-off-by: Wojtek Porczyk <woju@invisiblethingslab.com>

Include the new imager applications and fix the recursive File
operations to stop the installer pulling in the .git directory.

Add a few tidyups and a note about initramfs

Create a new rpiboot mode that uses a Linux initramfs to
implement mass-storage-gadget mode supporting EMMC and NVMe
block devices.

To use:
cd usbboot/mass-storage/gadget
../rpiboot -d .

Replace the example boot.img with a slightly more useful version
64-bit version that boots to a minimal busybox initrd with
USB enabled.

See https://github.com/raspberrypi/usbboot/issues/116

Fix help -c and -i default option

pieeprom-2022-02-08: Fix boot failure in locked secure-boot

The previous version would fail to boot if secure-boot mode was
locked via OTP settings.

recovery.bin prevent revoke_devkey from being set before the
customer key has been programmed.

Update bootloader to the latest stable release and use full SDRAM init in MSD / RAMDISK mode.

For test/debug purposes it's sometimes useful to erase the SPI
EEPROM using a chip-erase command. This has been available via
recovery.bin for a while but add it here for convenience.

The MSD (and secure-boot variant) bootloader has been updated to
fully initialise SDRAM in order to resolve problems when using
this method to run Linux ramdisks / initrd.
Therefore, MSD boot will not work on a system with a blank or
corrupted EEPROM. If so, an error message will be output to the
UART and the EEPROM should be programmed using the recovery
option.

e.g. previously, ../../filename would generate ../.sig

Previously, relative paths would confuse the file name generation regex.
With this change, only the final '.' character is matched as the
beginning of the file extension.

20220111~130126 release