Connecting a Pi to Gentoo using an Adafruit 954 cable

[[n00b@localhost]]

I've bought an Adafruit 954 USB-TTL cable to connect my raspberry pi to my laptop to do some low-level OS development. I have used crossdev to build arm-hardfloat-linux-gnueabi and aarch64-unknown-linux-gnu cross toolchains on my laptop and can compile code with the arm toolchain that runs on the Pi. My aim is to get to the point where I can use the aarch64 toolchain to build an aarch64 Gentoo stage 3 and start to experiment with kernel development.

I've been following the Adafruit lesson to connect the Pi to my laptop but I cannot get it to work.

I have a Raspberry Pi B+ running Gentoo and a Raspberry Pi 3B currently running Raspbian which I would like to connect to my Lenovo Thinkpad W530 running Gentoo. I first tried following the Adafruit lesson with the Raspberry Pi 3 and could get a login console - once - after which the terminal emulator (I've tried screen, minicom and microcom) locks up, I have to kill it from another terminal and cannot reconnect (hangs indefinitely). If I connect the USB cable prior to turning on the Pi (I have to use a separate power source for the Pi 3 as it requires 2A and the 954 cable only supplies 500mA) then I get a load of garbage streamed to the terminal before finally getting a login prompt. I was expecting to see messages from the kernel. I then tried again with the Raspberry Pi B+ (as I'm more familiar with Gentoo than Raspbian) and experienced the same symptoms. I am currently at work where I'm forced to use a Macbook and get the same symptoms there too.

I have followed the Arch wiki article on setting up Linux to use the serial console, editing /etc/inittab, /etc/securetty and /boot/cmdline.txt (instead of GRUB). The USB console appears on my laptop as /dev/ttyUSB0 but I'm not sure how the console connected to the GPIO pins appears to Raspbian or Gentoo on the Pi. My original /boot/cmdline.txt contained the line console=ttyAMA0,9600 on the B+ and console=ttyAMA0,115200 on the Pi 3. I could find no ttyAMA0 entries in /etc/inittab or /etc/securetty (the latter doesn't exist on Raspbian so I created it) so added them based on the Arch wiki article. I have tried various combinations of ttyAMA0 and ttyS0 in /boot/cmdline.txt, /etc/inittab and /etc/securetty but none of them work.

Would anyone who has one of these cables or a similar setup be able to help me get mine working? I've only just received my cable so if it doesn't work I'd like to be able to send it back.

Thanks.

[NeddySeagoon]

[n00b@localhost],

Its not a cable issue. See our [topic=1041352]64 bit Raspberry Pi thread.[/topic] and the Raspberry Pi Forum