ReadME Update (#15)

* readme update

Signed-off-by: Adam BZH <[email protected]>

* update readme for firmware hash check

---------

Signed-off-by: Adam BZH <[email protected]>

README.md

@@ -1,2 +1,51 @@
-# bluetooth-firmware-classic
-BLE firmware used by classic devices.
+# OneKey Classic 1/1S Bluetooth Firmware
+
+This repo contains bluetooth firmware for OneKey Classic 1 and 1S
+
+The firmware is based on NRF5 SDK 16.0.0, and build with Makefile
+
+## How to build
+
+```shell
+# make sure you have cmake, Python 3, amd aarm-none-eabi toolchain available in PATH
+
+# export your OWN key for firmware signing
+export BT_SIG_PK=$(cat <<EOF
+-----BEGIN EC PRIVATE KEY-----
+xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+-----END EC PRIVATE KEY-----
+EOF
+)
+
+# build binaries first
+./make_binaries.sh
+
+# then convert binaries to images with signature
+./make_images.sh
+```
+
+## How to verify firmware hash
+
+Install Python 3.x
+
+Download latest `ota.bin`, open a terminal in the same folder, invoke python, then run following code
+
+```python
+import struct, hashlib
+
+with open("ota.bin", mode="br") as f:
+    f.seek(0x0C)
+    codelen = struct.unpack("i", f.read(4))[0] - 512
+    f.seek(0x600)
+    print("".join(format(x, "02x") for x in hashlib.sha256(f.read(codelen)).digest()))
+```
+
+Single line version
+
+```python
+exec("""\nimport struct, hashlib\nwith open("ota.bin", mode="br") as f:\n    f.seek(0x0C)\n    codelen = struct.unpack("i", f.read(4))[0] - 512\n    f.seek(0x600)\n    print("".join(format(x, "02x") for x in hashlib.sha256(f.read(codelen)).digest()))\n""")
+```
+
+## License
+
+Please check License.md for details