On Sunday 31 January 2016 13:25:13 Ralph Corderoy wrote: > Does sound a bit dead then. Has it been connected to any test circuitry > yet? :-)
Yes. It has also been seen to work controlling the PWM and other light, but then it failed to read the SD Card again. As already mentioned, this device will *sometimes* work with a newly written SD Card, but rarely after the first boot. > > Even if it had worked, I would have queried the result. Without the > > SD Card, the Pi is only running the microcode that gets it booted and > > services the needed ports such as the USB. It wouldn't necessarily > > mean that the Pi could complete the boot. > > No, perhaps the SD-card connector's broken, I agree. But the test > sounds correct. The Zero has only the single On The Go USB port If the SD Card connector is broken, how come it sometimes works? It must be a very subtle problem; slow reads maybe? > provided by the BCM SoC, the SoC's GPU that boots it runs the first bit > of bootstrapping from ROM, so no SD card needed, and that can read the > next bootstrap stage from SD card into L2 cache (there's no RAM enabled > yet). But that first-stage ROM code also enables USB as a simple bulk > endpoint so you can boot over USB instead, and thus it should appear in > lsusb(8)'s output. > https://github.com/raspberrypi/tools/tree/master/usbboot#readme I still find this illogical, since the keyboard (and mouse when I've got it to boot full Raspbian) seem to work (at first, at least). They rely on the USB connector to work. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2016-02-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
