rpi-eeprom-update: Remove deprecated flashrom script options.

The muxing of the SPI EEPROM and analog audio pins makes flashrom
usage unreliable and having two flashing mechanisms adds unnecessary
complexity to this script.

The bootloader supports EEPROM updates from USB-MSD, Network
and rpiboot there is no real need to support flashrom within this
utility. Therefore, the option to use flashrom can be removed from this
script.

rpi-eeprom-update

@@ -28,7 +28,6 @@ FIRMWARE_RELEASE_STATUS=${FIRMWARE_RELEASE_STATUS:-default}
 FIRMWARE_IMAGE_DIR=${FIRMWARE_IMAGE_DIR:-${FIRMWARE_ROOT}/${FIRMWARE_RELEASE_STATUS}}
 FIRMWARE_BACKUP_DIR=${FIRMWARE_BACKUP_DIR:-/var/lib/raspberrypi/bootloader/backup}
 ENABLE_VL805_UPDATES=${ENABLE_VL805_UPDATES:-1}
-USE_FLASHROM=${USE_FLASHROM:-0}
 RECOVERY_BIN=${RECOVERY_BIN:-${FIRMWARE_ROOT}/${FIRMWARE_RELEASE_STATUS}/recovery.bin}
 BOOTFS=${BOOTFS:-/boot}
 VCMAILBOX=${VCMAILBOX:-/opt/vc/bin/vcmailbox}
@@ -61,10 +60,6 @@ BOARD_TYPE=
 # without a dedicate VL805 EEPROM.
 HAVE_VL805_EEPROM=0
 
-# Simple bootloader which is able to load start.elf in the event of a power
-# cut. This runs SDRAM at low speed and may have reduced functionality but
-# should be enough to run flashrom again.
-
 TMP_EEPROM_IMAGE=""
 TMP_BOOTFS_MNT=""
 
@@ -259,43 +254,9 @@ applyUpdate() {
       ) || die "Unable to validate EEPROM image package checksums"
    fi
 
-   if [ "${USE_FLASHROM}" = 0 ]; then
    applyRecoveryUpdate
-      return
-   fi
-
-   if [ -f "${BOOTLOADER_UPDATE_IMAGE}" ]; then
-      echo "WARNING: USE_FLASHROM is deprecated."
-      # Bootloader EEPROM chip-select is muxed with audio pin so disable audio
-      # LDO first to avoid sending noise to analog audio.
-      "${VCMAILBOX}" 0x00030056 4 4 0 > /dev/null || true
-      dtparam audio=off
-
-      # Switch the SPI pins to boot EEPROM
-      dtoverlay spi-gpio40-45
-      modprobe spidev
-      modprobe spi-bcm2835
-
-      prepareImage "${BOOTLOADER_UPDATE_IMAGE}"
-
-      echo "Applying bootloader update ${BOOTLOADER_UPDATE_IMAGE}"
-      flashrom -p "linux_spi:dev=/dev/spidev0.0,spispeed=${SPI_SPEED}" -w "${TMP_EEPROM_IMAGE}" || die "flashrom EEPROM update failed"
-
-      dtparam -R spi-gpio40-45
-      dtparam audio=on
-      ${VCMAILBOX} 0x00030056 4 4 1 > /dev/null || true
-   fi
-
-   if [ -f "${VL805_UPDATE_IMAGE}" ]; then
-      echo "Applying VL805 image ${VL805_UPDATE_IMAGE}"
-      vl805 -w "${VL805_UPDATE_IMAGE}"
-   fi
-
-   echo "Applying bootloader update ${BOOTLOADER_UPDATE_IMAGE}"
 }
 
-# Use the version reported by the loaded EEPROM instead of attempting to retrieve
-# this via flashrom to avoid unnecessary audio glitches.
 BOOTLOADER_CURRENT_VERSION=
 getBootloaderCurrentVersion() {
    if [ -f "${DT_BOOTLOADER_TS}" ]; then
@@ -393,23 +354,7 @@ checkDependencies() {
       die "sha256sum not found. On Debian, try installing the coreutilities package"
    fi
 
-   if ! command -v flashrom  > /dev/null && [ "${USE_FLASHROM}" = 1 ]; then
+   if [ ! -f "${RECOVERY_BIN}" ]; then
-      die "flashrom not found. On Debian, try installing the flashrom package."
-   fi
-
-   if [ ! -x "${VCMAILBOX}" ] && [ "${USE_FLASHROM}" = 1 ]; then
-      die "vcmailbox not found. On Debian, try installing the libraspberrypi-bin package."
-   fi
-
-   if ! command -v dtparam > /dev/null && [ "${USE_FLASHROM}" = 1 ]; then
-      die "dtparam not found. On Debian, try installing the libraspberrypi-bin package."
-   fi
-
-   if ! command -v dtoverlay > /dev/null && [ "${USE_FLASHROM}" = 1 ]; then
-      die "dtoverlay not found. On Debian, try installing the libraspberrypi-bin package."
-   fi
-
-   if [ "${USE_FLASHROM}" = 0 ] && [ ! -f "${RECOVERY_BIN}" ]; then
       die "${RECOVERY_BIN} not found."
    fi
 }
@@ -475,21 +420,6 @@ configuration file before it is applied to the new image. The modified
 output must contain at least 3 lines and should contain WAKE_ON_GPIO
 and POWER_OFF_ON_HALT settings.
 
-USE_FLASHROM
-
-USE_FLASHROM is deprecated and there is no support for this. The muxing
-of the SPI pins causes too many issues for this to ever be reliable.
-
-The flashrom update mechanism may be enabled by setting USE_FLASHROM=1. This
-also selects the vl805 tool instead of using recovery.bin to perform the
-update. This may be desirable if an immediate update is required or if an
-SD card is not present.
-However, this not recommended because the SPI pins are muxed with audio and other
-device drivers may be using SPI (e.g. HATs). This is also not safe in the
-event of a power failure during the update of the EEPROM.
-Changing the VL805 firmware whilst USB devices are attached may also cause
-those devices to stop working until after the system is reboot.
-
 FIRMWARE_RELEASE_STATUS
 
 Specifies the release status of the firmware to apply.