Downgrade Firmware
Original author @serrj-sv and community. Discuss here.
Gateway keeps the previous firmware before the update and you can be loaded from it.
If you update twice to a bad firmware, this method does not work.
If you have bad firmware from the factory - this method does not work.
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Open Gateway
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Solder USB UART adapter (GND to GND, RX to TX, TX to RX)
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Connect adapter to USB. UART setting: 38400 8n1, disable flow control (rts/cts)
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Power gateway with build-in USB power
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Сheck if boot is OK and there are no artifacts in console. If there are artifacts - check the wires, change the USB UART.
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Turn off gateway power
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Connect TP17 to ground (example USB case)
Don't solder TP17. It may brake UART data.
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Power gateway with build-in USB power
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Remove TP17/GND wire after
<RealTek>shows in console.
Attention: ALWAYS keep all UART logs and/or backups!
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Enable flash
<RealTek>snwbi -
Read boot_info from nand to memory
<RealTek>snwbrecc a0000000 140 800 -
Display boot_info in memory
<RealTek>db a0000000 40You will get something similar:
[Addr] .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 .A .B .C .D .E .F A0000000: 7C 91 00 00 E4 58 01 01 01 01 00 20 EC 04 C8 CF |....X..... .... A0000010: 00 00 20 EC 04 CB 19 00 00 82 80 04 62 C6 00 00 .. .........b... A0000020: 9A 40 04 72 E8 00 00 00 01 31 2E 30 2E 32 2E 30 [email protected] A0000030: 30 35 00 00 00 00 00 FF FF FF FF FF FF FF FF FF 05.............. -
Copy data to this calculator.
Scroll down to Swapped bootinfo dump section
It should change 4 bytes for first line:
A0000000: __ __ __ __ XX XX __ __ YY YY __ __ __ __ __ __ -
Paste the first line value from the calculator:
<RealTek>eb a000000 7C 91 00 00 E5 59 01 01 00 00 00 20 EC 04 C8 CF -
Check changes. Repeat step 3
All lines must match Swapped bootinfo dump section from the calculator!
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Clear nand before write
<RealTek>snwbeb 140 -
Write boot_info from memory to nand
<RealTek>snwbwecc a0000000 140 800 -
Reboot gateway (power off/on)
Gateway should starts with previous firmware.