Maybe there are some people owning this modem want to hack it, I have ported U-Boot 2009.08 from SG200 opensource code to these two modems.
*Download here*
For ZTE F460/F660 v3(they're compatible):
Github releases
For HGG420N:
Github releases
To flash it to your modem, you need:
Download 'u-boot-xxxx_533_128m_ddr3_nand.bin' and put it to the root directory of an tftp server running on your computer, set your computer's IP address to uboot environment: 'serverip'
Use UART to connect to your modem, keep press 'enter' to interrupt booting and type these commands
If you damaged your U-Boot or can't enter U-Boot console, follow these steps to use kwboot
kwboot usage
*Download here*
For ZTE F460/F660 v3(they're compatible):
Github releases
For HGG420N:
Github releases
To flash it to your modem, you need:
Download 'u-boot-xxxx_533_128m_ddr3_nand.bin' and put it to the root directory of an tftp server running on your computer, set your computer's IP address to uboot environment: 'serverip'
Use UART to connect to your modem, keep press 'enter' to interrupt booting and type these commands
tftp u-boot-xxxx_533_128m_ddr3_nand.bin (xxxx should be replaced) nand erase 0x0 0x100000 nand write 0x2000000 0x0 0x100000Then reboot, you will enter your new U-Boot
If you damaged your U-Boot or can't enter U-Boot console, follow these steps to use kwboot
kwboot usage