MT7621DA
I have a TP-LINK TL-R483G.
I want to try some transplants.
Some devices in OpenWrt use MT7621DA.
https://git.openwrt.org/?p=openwrt%2Fopenwrt.git&a=search&h=HEAD&st=commit&s=mt7621da
https://service.tp-link.com.cn/download/20222/TL-R483G%20V4.0升级软件20220113_2.0.1.zip
binwalk ./TL-R483G V4.0_2.0.1_Build_220113_Rel.45740n.bin
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
70016 0x11180 U-Boot version string, "U-Boot 1.1.3 (Jul 17 2019 - 21:23:56)"
198656 0x30800 uImage header, header size: 64 bytes, header CRC: 0x63858AB8, created: 2022-01-13 04:42:20, image size: 1636941 bytes, Data Address: 0x81001000, Entry Point: 0x81001000, data CRC: 0x64113980, OS: Linux, CPU: MIPS, image type: Multi-File Image, compression type: lzma, image name: "MIPS OpenWrt Linux-3.10.14"
198728 0x30848 LZMA compressed data, properties: 0x6D, dictionary size: 8388608 bytes, uncompressed size: 4868864 bytes
1901056 0x1D0200 Squashfs filesystem, little endian, version 4.0, compression:xz, size: 12303876 bytes, 3037 inodes, blocksize: 262144 bytes, created: 2022-01-13 04:42:28
Basically, this router generated firmware using MTK's OPENWRT SDK, and I found the firmware and unpacked it.
What can I get from the unpacked files to help with porting?
start by getting serial console access, you'll need sooner or later, anyway.
I seem to find unsoldered TTL pins, hoping TTL will help me get a root shell in the OS, I actually have a SPI burner as well.
It'd be interesting to discover whether it's wired up such that it can benefit from @arinc9's full-duplex gigabit LAN/WAN enhancement. If you look at the list of devices that can't, there are a number of TP-Link routers on it.
After welding the UART pin, it was found that the serial console did not output. Does this mean that the main board UART cable is not connected?
Or is the serial output of UBOOT turned off?
But it seems that zealous hackers have unencrypted the config file, but I can't seem to reproduce it.
If the UART line of the motherboard is not connected, to be honest, I don't want to modify the circuit. I hope that the UART output of UBOOT is turned off.
Maybe flashing UBOOT through SPI can solve the problem.