On Wed, Apr 27, 2016 at 10:52 AM, Edwin Maynard <[email protected]> wrote:
> Hello - > > I am a bit of a newbie when it comes to Linux and modifying uBoot is > something that is very new to me. I remember with the Rev B boards that you > needed to hold the S2 switch in order to boot from the SD card. This was > "fixed" by the time the Rev C hardware came out - I assume by patching > uBoot. Anyway, the current behavior (Debian Wheezy) when there is both a > valid eMMC image and valid SD image is to boot off the SD card regardless > of the state of the S2 switch. I get that this is because the uBoot on the > eMMC and the SD card are the same and both defaul to booting the SD card if > it is there. > > I'd like to get the old behavior back so that the S2 switch forces a boot > from the SD card and the eMMC will ignore the SD card for the purpose of > finding the boot image. > > The reason for this is that I am making a deeply embedded system and want > to be able to update the eMMC by booting from SD card using the scripts > provided (set the cmdline in uEnv.txt to make it a flasher) and I won;t > have physical access to the uSD slot. > > Alternatively, and here is where I am a rank newbie, is there a way > (script) that I can boot into the eMMC (no boot image on the SD card) and > trigger a reflash of the eMMC? > Rebuild u-boot: https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-Bootloader:U-Boot after you've patched above, find this and remove "mmc 0" http://git.denx.de/?p=u-boot.git;a=blob;f=include/configs/am335x_evm.h;h=6ebe0b3866f9b137472cc080c9eb8f1e38233186;hb=refs/tags/v2016.03#l87 87 <http://git.denx.de/?p=u-boot.git;a=blob;f=include/configs/am335x_evm.h;h=6ebe0b3866f9b137472cc080c9eb8f1e38233186;hb=refs/tags/v2016.03#l87> func(MMC, mmc, 0) \ 88 <http://git.denx.de/?p=u-boot.git;a=blob;f=include/configs/am335x_evm.h;h=6ebe0b3866f9b137472cc080c9eb8f1e38233186;hb=refs/tags/v2016.03#l88> func(LEGACY_MMC, legacy_mmc, 0) \ Flash it "only" to eMMC, now the eMMC will never look to microSD.. 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/CAOCHtYgpwkWJX6DxNwNkH1F3naic4WKX6LwDTADg1TOoJqv8NA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
