Hi, On 10/17/20 1:31 PM, Robert Carnecky (Neopsis) wrote: > Finally, I managed to boot into barebox menu using UART1 (/dev/ttyS0) > as the console. The solution was to remove all UART related overlays > from config.txt and only activate UART1. > > enable_uart=1 > > Anyway, another problem occurred. When booting via barebox the CPU > serial number is wrong. Obviously, barebox somehow manipulates the > internal structures and > > cat /proc/cpuinfo > > returns always > > Hardware : BCM2835 > Revision : 0000 > Serial : 0000000000000000 > Model : Raspberry Pi Compute Module 3 IO board V3.0 > > When I boot the same image directly without barebox boot loader, the > info is OK. I found some discussions about U-Boot and wrong serial > number here > > https://www.raspberrypi.org/forums/viewtopic.php?t=183474#p1162778 > > maybe that's barebox related too. Anyway, that is a definitive no go > with barebox for us because parts of our software are expecting the > unique serial number. I believe you can boot Linux with /vc.dtb and you'll get the same device tree passed to Linux as if you booted without passing through barebox. > > Robert > > > On Fri, Oct 9, 2020 at 4:18 PM Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote: >> >> Hello Robert, >> >> On 10/9/20 2:30 PM, Robert Carnecky (Neopsis) wrote: >>>> Try adding to arch/arm/dts/bcm2837-rpi-cm3.dts: >>>> >>>> &uart1 { >>>> pinctrl-names = "default"; >>>> pinctrl-0 = <&uart1_gpio14>; >>>> status = "okay"; >>>> }; >>> >>> I extended arch/arm/dts/bcm2837-rpi-cm3.dts as advised + >>> additionally I set UART0 to pins 32/33. >>> >>> &uart0 { >>> pinctrl-names = "default"; >>> pinctrl-0 = <&uart0_gpio32>; >>> status = "okay"; >>> }; >>> >>> I still cannot see Barebox console on boot, however, the Barebox loader >>> starts in 3 seconds my kernel and I get the Linux console output on >>> UART1/ttyS0. >> >> Strange that this made the kernel boot now. Maybe somewhere an unclocked >> peripheral was being accessed before? >> >>> Now my Linux boots as expected, unfortunately without >>> visible Barebox console. I tried all Barebox console setting >>> (NONE/ALL/FIRST), same result, no Barebox console output on UART0 >>> or UART1. >> >> Huh, you did listen at the UART0 _before_ the RS-485 transceiver? >> UART0 should work, at least it apparently did when the CM3 support >> was added. >> >>>> If that doesn't help, use CONSOLE_ACTIVATE_ALL and listen >>>> on UART0 before the RS-485 transceiver and paste the >>>> dmesg and devinfo input you get. >>> >>> # dmesg | grep tty >>> [ 0.000000] Kernel command line: console=ttyS0,115200 >>> coherent_pool=1M snd_bcm2835.enable_compat_alsa=0 >>> snd_bcm2835.enable_hdmi=1 snd_bcm2835.enable_headphones=1 >>> 8250.nr_uarts=1 bcm2708_fb.fbwidth=656 >>> bcm2708_fb.fbheight=416 bcm2708_fb.fbswap=1 >>> smsc95xx.macaddr=B8:27:EB:C5:7D:E3 vc_mem.mem_base=0x3ec00000 >>> vc_mem.mem_size=0x40000000 root=/dev/mmcblk0p2 console=ttyS0,115200 >>> rootfstype=ext4 elevator=deadline rootwait >>> [ 1.289058] printk: console [ttyS0] disabled >>> [ 1.289175] 3f215040.serial: ttyS0 at MMIO 0x0 (irq = 53, base_baud >>> = 50000000) is a 16550 >>> [ 1.945483] printk: console [ttyS0] enabled >>> [ 2.432604] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 81, >>> base_baud = 0) is a PL011 rev2 >>> >>> # stty -F /dev/ttyAMA0 115200 >>> # cat /etc/inittab > /dev/ttyAMA0 <- OK >> >> I meant dmesg under barebox, if UART1 fails to output, but UART0 can be >> read before the transceiver. >> >> On 10/6/20 1:32 AM, Robert Carnecky (Neopsis) wrote: >>> I played a bit more with the config.txt settings and when I activated the flag >>> >>> uart_2ndstage=1 >>> >>> I got the barebox console! Here a snippet from the 2stage while >>> logging the UART lading. >> >> Oh. That would indicate that there is some sort of initialization missing. >> uart_2ndstage=1 initializes the UART for VideoCore use apparently and from >> there on, it works. >> >>> What I do not understand: how the loaded /mfs/sd/bcm2710-rpi-cm3.dtb >>> and the overlays >>> cooperate with the Barebox device tree? Does it mean we have two sets >>> of device tree >>> files? >> >> Yes. The VideoCore device tree is available in barebox as /vc.dtb, >> see e390c8799d91 ("ARM: rpi: save fdt that was passed from VideoCore") >> >> >> Hope this helps, >> Ahmad >> >> -- >> Pengutronix e.K. | | >> Steuerwalder Str. 21 | http://www.pengutronix.de/ | >> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | >> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
