Thanks, I understand. Turns out what I needed could have been accomplished without rebuilding U-Boot. I had to set the value of a GPIO line, and there is a U-Boot script command for that.
So, a re-built U-Boot wouldn't have produced any benefit. However, I need to figure out how to force this GPIO to stay LOW during kernel startup. Apparently the kernel switches it HIGH (or affects some sort of a reset that forces GPIO_137 high). So, the GPIO line is switched down via "gpio clear 137" U-Boot command, but a couple of seconds later comes back up, and stays up until the user software can be brought up to switch it off. It seems that most interactions with the registers, including setting GPIO levels, can be achieved via the DTS? I see some examples for BBB, but haven't found anything for the xM. Thanks! On Monday, October 21, 2013 6:48:25 PM UTC-4, RobertCNelson wrote: > > On Mon, Oct 21, 2013 at 5:00 PM, porkupan <vladimi...@gmail.com<javascript:>> > wrote: > > The U-Boot built from the Mainline sources doesn't seem to be able to > load > > the kernel. > > > > Here is how i built it: > > git clone git://git.denx.de/u-boot.git u-boot-main > > cd u-boot-main/ > > git checkout --track -b omap3 origin/master > > > > make CROSS_COMPILE=arm-linux-gnueabihf- mrproper > > make CROSS_COMPILE=arm-linux-gnueabihf- omap3_beagle_config > > make CROSS_COMPILE=arm-linux-gnueabihf- > > > > U-Boot builds, I copied the u-boot.img into the Beagleboard xM boot SD > > (U-Boot FAT partition). The SD has been made from RobertCNelson > > preconfigured Ubuntu demo image, with currently operational U-Boot. The > new > > U-Boot fails to load the kernel image: > > > > U-Boot SPL 2013.07-00016-gbc15ff8 (Aug 16 2013 - 10:41:31) > > OMAP SD/MMC: 0 > > reading u-boot.img > > reading u-boot.img > > > > > > U-Boot 2013.10 (Oct 21 2013 - 15:03:24) > > > > OMAP3630/3730-GP ES1.2, CPU-OPP2, L3-200MHz, Max CPU Clock 1 Ghz > > OMAP3 Beagle board + LPDDR/NAND > > I2C: ready > > DRAM: 512 MiB > > NAND: 0 MiB > > MMC: OMAP SD/MMC: 0 > > *** Warning - readenv() failed, using default environment > > > > In: serial > > Out: serial > > Err: serial > > Beagle xM Rev C > > No EEPROM on expansion board > > Die ID #1c9000029ff800000163810c0d02f018 > > Net: usb_ether > > Hit any key to stop autoboot: 0 > > mmc0 is current device > > gpio: pin 173 (gpio 173) value is 0 > > gpio: pin 4 (gpio 4) value is 0 > > SD/MMC found on device 0 > > reading uEnv.txt > > 945 bytes read in 3 ms (307.6 KiB/s) > > Loaded environment from uEnv.txt > > Importing environment from mmc ... > > Running uenvcmd ... > > reading zImage > > 3812504 bytes read in 239 ms (15.2 MiB/s) > > reading initrd.img > > 3196182 bytes read in 199 ms (15.3 MiB/s) > > reading /dtbs/omap3-beagle-xm.dtb > > 13511 bytes read in 8 ms (1.6 MiB/s) > > ## Error: "expansion_args" not defined > > Kernel image @ 0x80300000 [ 0x000000 - 0x3a2c98 ] > > Wrong Ramdisk Image Format > > Ramdisk image is corrupt or invalid > > ** File not found /boot/uImage ** > > Booting from nand ... > > > > no devices available > > Wrong Image Format for bootm command > > ERROR: can't get kernel image! > > ** File not found /boot/zImage ** > > OMAP3 beagleboard.org # > > > > Is there a working U-Boot source/build environment available? Or > patches to > > build the mainline U-Boot? > > > > > Please don't mix and match source/guide's etc.. It's pain to support.. > > http://eewiki.net/display/linuxonarm/BeagleBoard > > Regards, > > -- > Robert Nelson > http://www.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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
