Retevis C62 short flash guide.

hardware/c62.md

@@ -5,6 +5,31 @@ multi-core SoC that pairs an ARM Cortex-M33 application core with a Cadence HiFi
 DSP and a small NPU. The DSP and NPU drive the radio's "AI noise reduction". RF
 is handled by a BK4819, the same chip found in the Quansheng UV-K5, with a BK1080
 for broadcast FM.
+
+## flash current build
+
+28 october 2026:
+Expect working fm rx and tx, no battery status, empty config after device reboot.
+Find openrtx-c62.zip on https://github.com/OpenRTX/OpenRTX/pull/550 and unzip 
+
+Where to find cskburn tool
+https://github.com/LISTENAI/cskburn/releases/tag/v1.30.0
+    cskburn --version
+    v1.30.0 (403)
+Note 1.31 might have a bug, unable to take backup firmware from device.
+
+Connect kenwood 2 plug to usb, press lower ptt and turn on C62.  
+You have to do this after every action, as the radio gets reset.
+
+Check cable communication ( serial port might be different )
+    cskburn -C 6 -s /dev/ttyUSB4 --chip-id -b 115200
+
+Take backup off current firmware:
+    cskburn --read "0x0:4194304:factory_<chipid>.bin" -C 6 -b 115200 -v -s /dev/ttyUSB4
+
+Put downloaded OpenRTX bin on the radio
+   cskburn -s /dev/ttyUSB4 -C 6 -b 115200 0x000000 zephyr.bin
+
 
 ## Development status