On Wed, Jul 20, 2022 at 2:14 PM Patrick Welche <[email protected]> wrote: > > [I posted this to port-arm around 4th July, but hasn't made it. Reposting > here in case useful...] > > > tl;dr On a raspberry pi zero W, updating the firmware allows the disable-bt > overlay to function resulting in a stable serial console. > > Experimental method(!) > > - grab > https://nycdn.netbsd.org/pub/NetBSD-daily/HEAD/202207031950Z/evbarm-earmv6hf/binary/gzimg/rpi.img.gz > - gunzip / dd to card / remove "console=fb" from first line of cmdline.txt > - connect raspberry pi zero W 1.1 to serial port via pins 4,6,8,10 which boots > - watch output with tip & baud rate 115200 > - all is well until /etc/rc.local is run, changing the cpu frequency, > which messes up the baud rate because the raspberry pi zero w, by > default, reserves its real UART for bluetooth, and attaches a "mini" > UART to the console, and this "mini" UART doesn't appear to have its > own clock: > ... > [ 1.0000000] simplebus0 at armfdt0: Raspberry Pi Zero W Rev 1.1 > ... > [ 1.0000000] plcom0 at simplebus1: ARM PL011 UART > ... > [ 1.0000000] com0 at simplebus1: BCM AUX UART, 1-byte FIFO > [ 1.0000000] com0: console > ... > Starting local daemons:. > JRQ > ܊VP�҇KZ�� � ���Q
Try adding this line to /boot/config.txt. core_freq=250 [snip] > BTW my impression is there is no bluetooth support, so we are not > missing anything by disabling it? (as opposed to miniuart-bt). bthfive worked at the time it was implemented till FDTized. Currently btattach fails. > > > Cheers, > > Patrick
