Robert, So, I have a custom overlay for a physical custom cape . . . as of this moment, I have a few gpio's( I think around 22 ish ), 6 PWM's,, and eventually I can put an ADC into that same overlay. Right, now for the ADC I'm just loading the "stock" ADC overlay for ADC functionality. Additionally, in the future I may also need to add uart4 back into the mix. For now, our current cape no longer needs uart.
The question I have is . . . Would this improve anything for us ? Right now, I just load the custom overlay through initramfs, which also seems fine. For this project we do not really have a need for an LCD, but that might change in the future. At least for *some* hardware configurations. On Fri, Dec 23, 2016 at 3:50 PM, Robert Nelson <[email protected]> wrote: > Okay, i have a version of u-boot with overlays enabled, ready for some > basic testing.. > > *************Background*************************************** > > in u-boot we are doing: > > dtb= is loaded at ${fdtaddr} > > We read /boot/uEnv.txt for (dtb_overlay=<path/file.dtbo>) > > then load it, into ${rdaddr} #(no reason that specific address) > > Then we must run thru this routine: > > fdt addr ${fdtaddr} > fdt resize; > fdt apply ${rdaddr} > fdt resize; > > Without the "fdt resize, the jump to kernel bomb's in bootz." > > ***************************************************************** > > *************Actual testing...*************************************** > > Step 1: Do you have a usb serial adapter to monitor the boot process? > > no = stop reading now... till you have one in hand... > yes = please continue > > Step 2: Remove /uEnv.txt (i forgot to code that path in this test) > > rm /uEnv.txt > > Step 3: Update u-boot to v2017.01-rc2 > > cd /opt/scripts/tools/developers/ > git pull > ./update_bootloader.sh --use-beta-bootloader > > On reboot, it should show: > > U-Boot SPL 2017.01-rc2-00002-g52b3c56009 (Dec 23 2016 - 16:22:21) > Trying to boot from MMC1 > > U-Boot 2017.01-rc2-00002-g52b3c56009 (Dec 23 2016 - 16:22:21 -0600), > Build: jenkins-github_Bootloader-Builder-493 > > If not, eMMC probably messing with you.. > > dd if=/dev/zero of=/dev/mmcblk1 bs=1M count=10 > > Step 4: /boot/uEnv.txt > > remove "cape_universal=enable" we dont want any false posititves... > > dtb_overlay=/lib/firmware/BB-UART2-00A0.dtbo > > before: > kernel: > root@beaglebone:~# dmesg | grep serial > [ 2.082007] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq = 158, > base_baud = 3000000) is a 8250 > [ 2.096583] 481a6000.serial: ttyS3 at MMIO 0x481a6000 (irq = 159, > base_baud = 3000000) is a 8250 > [ 20.106023] systemd[1]: Created slice system-serial\x2dgetty.slice. > > after: > U-Boot: > loading /boot/dtbs/4.4.39-ti-r75/am335x-boneblack-wireless.dtb ... > 64988 bytes read in 163 ms (388.7 KiB/s) > debug: [dtb_overlay=/lib/firmware/BB-UART2-00A0.dtbo] ... > loading /lib/firmware/BB-UART2-00A0.dtbo ... > 883 bytes read in 276 ms (2.9 KiB/s) > > kernel: > root@beaglebone:~# dmesg | grep serial > [ 2.081559] 44e09000.serial: ttyS0 at MMIO 0x44e09000 (irq = 158, > base_baud = 3000000) is a 8250 > [ 2.095942] 48024000.serial: ttyS2 at MMIO 0x48024000 (irq = 159, > base_baud = 3000000) is a 8250 > [ 2.096807] 481a6000.serial: ttyS3 at MMIO 0x481a6000 (irq = 160, > base_baud = 3000000) is a 8250 > [ 20.316939] systemd[1]: Created slice system-serial\x2dgetty.slice. > > Step 5: Profit!!! ;) > > ***************************************************************** > > I know it's a little limited, but something for testing over Christmas. ;) > > FAQ: > > What does this solve? Lots of random kernel races... (looking at > video/emmc/etc)... As U-Boot updates the final *.dtb and not the > kernel... > > What about 2+ overlays? Maybe next week, for Christmas you get one.. ;) > > Does this replace the current method? No it just improves things.. > > What have you tested it on? Just BB-UART2-00A0.dtbo and then i wrote > this email up and got ready to go home... > > Will it read the eeprom and auto load the correct overlay? Sure, > sometime between next week and the start of the new year... ;) > > Will this fix the issue with the painful out of box experience with > LCD3/LCD4/LCD7? Correct, as long as they have an eeprom. ;) > > How do i actually test things? > > Easiest, /boot/uEnv.txt > > dtb=am335x-boneblack-overlay.dtb > dtb_overlay=/lib/firmware/xyz.dtbo > > Regards, > > -- > Robert Nelson > https://rcn-ee.com/ > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/beagleboard/CAOCHtYiSVX8-koZ2DFH36xUqEAcSwDn% > 2Btv8phoYDE8O-tpvUXw%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORrdkUTY93VDCG9D2RyCHyEcPUs2KHxHvipWdH9-22dF1w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
