I guess the real question is, how do we update the Beaglebone's MLO and u-boot.img if we are running the OS from eMMC?
Thanks, Robert On Friday, July 17, 2020 at 5:25:19 PM UTC-5, Robert Cachro wrote: > > Hi, > > In an effort to mitigate a potential security vulnerability, I am > attempting to disable u-boot Serial Console output which I am monitoring > via FTDI. This can be done by modifying the source of U-Boot to configure > the device for silent booting ( > https://github.com/rickyzhang82/u-boot4bbb/blob/master/doc/README.silent) > > I am running Debian 9.9 Stretch IoT on a Beaglebone Black Wireless. > > Here is what I have done thus far: > ------------------------------------------------- > *Download U-boot* > ----------------------------------------------- > wget ftp://ftp.denx.de/pub/u-boot/u-boot-2019.04.tar.bz2 > tar -xjf u-boot-2019.04.tar.bz2 > cd u-boot-2019.04/ > ## from https://rcn-ee.com/repos/git/u-boot-patches/ > wget -c > https://github.com/eewiki/u-boot-patches/raw/master/v2019.04/0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch > wget -c > https://github.com/eewiki/u-boot-patches/raw/master/v2019.04/0002-U-Boot-BeagleBone-Cape-Manager.patch > > patch -p1 < 0001-am335x_evm-uEnv.txt-bootz-n-fixes.patch > patch -p1 < 0002-U-Boot-BeagleBone-Cape-Manager.patch > ------------------------------------------------- > *Modify U-boot to disable console output* > ------------------------------------------------- > cd /u-boot-2019.04/include/configs > vim am335x_evm.h > (add bolded) > *#define CONFIG_SILENT_CONSOLE* > *#define CONFIG_SYS_DEVICE_NULLDEV* > *#define CONFIG_SILENT_CONSOLE_UPDATE_ON_RELOC* > … > #define CONFIG_EXTRA_ENV_SETTINGS \ > DEFAULT_LINUX_BOOT_ENV \ > DEFAULT_MMC_TI_ARGS \ > DEFAULT_FIT_TI_ARGS \ > "bootpart=0:2\0" \ > "bootdir=/boot\0" \ > "bootfile=zImage\0" \ > "board_eeprom_header=undefined\0" \ > "fdtfile=undefined\0" \ > *"silent=1\0" \* > "console=ttyO0,115200n8\0" \ > ------------------------------------------------- > *Compile* > ------------------------------------------------- > cd ../.. > make ARCH=arm CROSS_COMPILE=${CC} distclean > make ARCH=arm CROSS_COMPILE=${CC} am335x_evm_defconfig > make ARCH=arm CROSS_COMPILE=${CC} > ls -l MLO u-boot.img > ------------------------------------------------- > *Update u-boot on image* > ------------------------------------------------- > dd if=MLO of=/dev/mmcblk1 bs=512 seek=256 count=256 conv=notrunc > dd if=u-boot.img of=/dev/mmcblk1 bs=512 seek=768 count=1024 conv=notrunc > ------------------------------------------------- > *Reboot* > ------------------------------------------------- > > > However, the serial console which I am monitoring via FTDI cable still > shows output. > > > Any thoughts? > > I think the final step, where I update u-boot on my current image, may not > be done correctly. > > > Thank you, > > Robert > > -- 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/261cf27a-d530-4898-a88b-b8d845e82e90o%40googlegroups.com.
