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OpenKirin / Documentation

Unofficial and (hopefully) useful documentation to implement your own Android based rom using a Kirin platform.
GNU General Public License v3.0
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UART information #3

Open bm16ton opened 9 months ago

bm16ton commented 9 months ago

Hello, just curious if you have/can release any information on debug uart access. For instance i have a Huawei mate 9 kirin960, its muic is fsa9688c. The debug uart is 6. The uart can be muxed thru to usb-c pins. According to the fsa9688c's datasheet the rx/tx lines should be muxed thru usb dp+ dp-. I have patched the kernels driver adding a new sysfs file to force a manual bypass for uart6. The usb dp+dp- do switch to 1.8v and the usb stops responding as a usb device, but nothing I throw at /dev/ttyAMA6 cause any change on those pins, have tried the other tty's as well just in case. I have a unlocked bootloader and unlocked fastboot with fastboot oem uart enable going thru fine. I make sure to boot with uart attached to usb-c because its supposed to have an autodetect feature at boot. Im sure people who are developing for these soc's must be using uart. This soc and maybe others in the family also have the debug uart pins attached to the jtag pins and they can all be muxed over to the sdcard pins. That wouldn't really work for me and I couldn't find any sdcard/dual sim holder breakouts (tho i dont know what the official name is for those things so my googling was difficult). Well sorry for being long winded I have spent a lot of time on this with no resources so any documentation/help is greatly appreciated.

bzy-080408 commented 4 months ago

what about try "fastboot oem UART on" BTW this may be only allowed by some boardsoftware(factory software)