On Tue, Oct 20, 2020 at 6:04 AM Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx> wrote: > > On Tue, 2020-10-20 at 05:59 +0200, Rouven Czerwinski wrote: > > On Tue, 2020-10-20 at 00:29 +0200, Robert Carnecky (Neopsis) wrote: > > > On Mon, Oct 19, 2020 at 11:28 AM Ahmad Fatoum < > > > a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > Hello, > > > > > > > > On 10/18/20 1:17 AM, Robert Carnecky (Neopsis) wrote: > > > > > On Sat, Oct 17, 2020 at 11:29 PM Ahmad Fatoum < > > > > > a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > > > 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. > > > > > > > > > > Yes, but then I lose my Linux console! A summary, in all cases > > > > > Barebox device > > > > > tree in arch/arm/dts/bcm2837-rpi-cm3.dts was updated following > > > > > your hint, e.g. > > > > > > > > > > / { > > > > > chosen { > > > > > stdout-path = "&uart1"; > > > > > }; > > > > > }; > > > > > > > > > > &uart1 { > > > > > pinctrl-names = "default"; > > > > > pinctrl-0 = <&uart1_gpio14>; > > > > > status = "okay"; > > > > > }; > > > > > > > > > > &uart0 { > > > > > pinctrl-names = "default"; > > > > > pinctrl-0 = <&uart0_gpio32>; > > > > > status = "okay"; > > > > > }; > > > > > > > > > > 1. Booting kernel direct, works as expected (console on uart1), > > > > > expected behavior > > > > > > > > > > kernel=zImage > > > > > enable_uart=1 > > > > > dtoverlay=uart0,txd0_pin=32,rxd0_pin=33,pin_func=7 > > > > > dtoverlay=uart1,txd1_pin=14,rxd1_pin=15 > > > > > > > > > > 2. With Barebox loader. The same config.txt as in case 1), > > > > > - no Barebox console > > > > > - kernel boots with the console on uart1 > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > enable_uart=1 > > > > > dtoverlay=uart0,txd0_pin=32,rxd0_pin=33,pin_func=7 > > > > > dtoverlay=uart1,txd1_pin=14,rxd1_pin=15 > > > > > > > > > > 3. With Barebox loader, no uart overlays in config.txt. > > > > > - Barebox console on uart1 ok, > > > > > - kernel console on uart1 > > > > > - almost done), but ... no cpuinfo > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > enable_uart=1 > > > > > > > > > > 4. With Barebox loader, no uart overlays in config.txt, Linux > > > > > boots with vc.dtb. > > > > > - Barebox console on uart1 ok > > > > > - no Linux console, Linux boots with cpuinfo ok > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > enable_uart=1 > > > > > > > > > > I did not found any combination when I get the Barebox console > > > > > and > > > > > Linux console on uart1 > > > > > and with cpuinfo ok. If the serial number is not needed, case > > > > > 3) should be ok. > > > > > > > > What happens if you combine 2. and 4. ? > > > > So you have enable_uart=1, the uart overlays _and_ Linux boots > > > > with vc.dtb? > > > > > > Negativ. Whenever I enable overlays in the config.txt that map > > > uart0 > > > to pin32/33 and > > > uart1 to pin 14/15 (console), I do not get Barebox console. It does > > > not depend on the device > > > tree passed to the kernel. This interaction between Barebox device > > > tree and Raspberry config.txt > > > overlays is a bit strange for me. > > > > > > Just an idea - does Barebox fully support this hardware? From the > > > 2835 > > > ARM Peripherals Guide, > > > chapter 2.2 miniUART : > > > > > > > The implemented UART is not a 16650 compatible UART However as > > > > far as possible > > > > the first 8 control and status registers are laid out like a > > > > 16550 UART. Al 16550 register > > > > bits which are not supported can be written but will be ignored > > > > and read back as 0. > > > > All control bits for simple UART receive/transmit operations are > > > > available. > > > > > > Barebox has support for NS16650 ( CONFIG_DRIVER_SERIAL_NS16550) but > > > not for > > > Raspberry miniUART. > > > > > > Anyway, I am giving up. I am sure I tested all combinations of > > > overlays, I have written my > > > own dts, nothing works as I need (console=uart1, incl. proper > > > serial > > > number handling). > > > There is no problem to get the console on uart0/ttyAMA0, but not on > > > uart1/ttyS0. > > > The Raspberry way how they are handling uarts lacks all logic and > > > is completely > > > unclear. > > > > Hi, > > > > looking into arch/arm/dts/bcm2837-rpi-cm3.dts: > > / { > > chosen { > > stdout-path = &uart0; > > }; > > }; > > > > The CM3 module is currently default configured to use uart0 as the > > stdout path, while bcm2837-rpi-3.dts is configured for uart1. > > This was done in ab76f9d09d3b7b77fc00d84bc2fac6bfbf82c69c after the > > miniuart support was added to the NS16550 driver > > in 77de547cd179b910cdcb8530df15d77a0fc66a3c. > > Disregard this, I didn't read the whole thread. There however was > another user who tried to use the miniuart and had failures on probe on > the CM3. Unfortunately the barebox archives don't have these mails, > I'll attach an mbox which has the whole thread. > > > Regards, > Rouven Czerwinski > The thread sent by Rouven describes really the same issue and, like me, without a solution. As I wrote in my summary, there is one combination of config.txt and barebox device tree booting into barebox console on uart1 and kernel console on uart1: barebox device tree: / { chosen { stdout-path = "&uart1"; }; }; &uart1 { pinctrl-names = "default"; pinctrl-0 = <&uart1_gpio14>; status = "okay"; }; &uart0 { pinctrl-names = "default"; pinctrl-0 = <&uart0_gpio32>; status = "okay"; }; config.txt: kernel=barebox-raspberry-pi-cm3.img enable_uart=1 Unfortunately, in this case the content of /proc/cpuinfo in Linux is wrong, which is in my opinion barebox bug. Robert _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
