snagrecover: am62x: Issue correct DFU command sequence

Newer versions of U-Boot for AM62x platforms have a different behavior when
booting from DFU. With previous versions, U-Boot proper and SPL would both
run after a single detach. With recent versions, only spl runs after the
first detach and u-boot proper has to be sent again.

Change the AM62x recovery procedure to accomodate these newer U-Boot
versions.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>

src/snagrecover/firmware/firmware.py

@@ -74,8 +74,7 @@ def am62x_run(dev: usb.core.Device, fw_name: str, fw_blob: bytes):
 	print("Downloading file...")
 	dfu_cmd.download_and_run(fw_blob, partid, offset=0, size=len(fw_blob))
 	print("Done")
-	if fw_name == "tispl":
-		# run tispl firmware
+	if fw_name == "u-boot":
 		print("Sending detach command...")
 		dfu_cmd.detach(partid)
 

src/snagrecover/recoveries/am62x.py

@@ -18,6 +18,17 @@ def main():
 		usb_addr = parse_usb_addr(recovery_config["firmware"]["tiboot3"]["usb"])
 
 	dev = get_usb(usb_addr)
-	run_firmware(dev, "u-boot")
+
 	run_firmware(dev, "tispl")
+	run_firmware(dev, "u-boot")
+
+	time.sleep(2)
+
+	# For newer versions of U-Boot, only SPL will run from the
+	# previous commands and the u-boot firmware should be sent
+	# one more time.
+
+	dev = get_usb(usb_addr, error_on_fail=False)
+	if dev is not None:
+		run_firmware(dev, "u-boot")