Hi Sylvain, Just to get to some conclusion on the build error: When YoSYS, Nextpnr and Icestorm are all compiled from latest master, the gateware compilation succeeds. Once I applied your patch: diff --git a/firmware/ice40-riscv/icE1usb/gps.c b/firmware/ice40-riscv/icE1usb/gps.c index c1ad3a8..4084b08 100644 --- a/firmware/ice40-riscv/icE1usb/gps.c +++ b/firmware/ice40-riscv/icE1usb/gps.c @@ -271,6 +271,7 @@ gps_init(void) return; } +#if 0 /* If success was at 9600 baud, need to speed up */ if (i == 0) { /* Configure GPS to use serial at 115200 baud */ @@ -287,4 +288,5 @@ gps_init(void) /* Configure GPS to be GPS-only (no GLONASS/BEIDOU) */ _gps_send("PCAS04,1"); +#endif } The module is not stuck anymore at "[+] GPS ok at 9600 baud", and now I have "Command>" on uart, and the USB enumeration works (CDC interface is up and running). let me try it out with a BTS and will report back. Thanks for the help so far! Regards, Csaba