Bryn Wolfe
New Member
Intel's newest E3900 series SoC chips (formerly known as Apollo Lake) come with two built-in UARTs. I've installed Ubuntu 16.04 on a E3950-based SBC and it seems to function normally except for the serial ports. A "dmesg | grep serial" shows that the OS registers two ports (serial0 at ttyS5 and serial1 at ttyS6). However, an "ls /dev/ttyS*" specifically excludes those two registered ports. I have no idea where to find these two ports if they're not in /dev so I can tickle the interface even with something as simple as "echo hello > ttyS5". I've upgraded the kernel to 4.18.14 in hopes that it might have some drivers that magically put these ports back into /dev, but no joy. If these ports are registered but not in /dev, where else might they be? I know the E3900 chipset is not officially released by Intel but hope that somebody else has gone through this process and gotten past this problem.
