Hello. Thank you for your hints, but I am still unable to boot from eMMC. 1) mmc partconf commands >mmc partconf 0 1 1 0 >mmc partconf 0 1 0 0 I think partconf flags correcponds to BOOT_ACK, BOOT_PARTITION_ENABLE, PARTITION_ACCCESS. So, I need to do something like below instead to make sure my u-boot is written to offset 1KB on eMMC? >mmc partconf 0 1 7 1 >mmc write xxxx 7D0 yyyy >mmc partconf 0 1 7 0 (Though I have to figure out what xxxx and yyyy are.) Since I have to write u-boot data to 1KB offset, I need to specify 7 (user partition)? I could better use dd command from my host, but after I issue: >mmc partconf 0 1 0 1 "ums 0 mmc 0" command gives me "bad MBR sector signature 0x0000" error (so it does not appear on host as block device), so I think I cannot access it from the host. 2) J1/J2 jumpers This may be board specific (Technexsion) issue, but I am still confused. Looking into: https://www.nxp.com/docs/en/quick-reference-guide/PICO-iMX7D-QSG.pdf I can see following jumper modes. i) Download mode ii) Boot mode I am still unsure on exactly how these affects the board behavior. (Also I can see these are different from the one from PICO-PI-IMX6UL document - so it also make me wonder if it is document typo or accurate info.) ________________________________ From: Vanessa Ayumi Maegima Sent: Tuesday, October 3, 2017 9:14 PM To: Takashi Matsuzawa Cc: Vanessa Maegima; meta-freescale@yoctoproject.org; desrochers.philippe@gmail.com; festevam@gmail.com Subject: Re: [3rdparty][PATCH v2] imx7d-pico: Add machine configuration (booting) Hi Takashi, On Tue, Oct 3, 2017 at 7:35 AM, Takashi Matsuzawa wrote: > Hello. > By the way, I found I could boot successfully using this wic image (only one > ext4 partition) by the following. > So, it might have to do something with the boot code - but I still not sure > what being wrong. > > 1) Connect power (USB-C cable) > 2) sudo imx_usb u-boot.imx > > Then, the linux successfull boot into the logon prompt. > This seems to work regardless of the J1 jumper setting (so eMMC boot setting > is not working and always being serial download mode?) > > > ________________________________ > From: Takashi Matsuzawa > Sent: Tuesday, October 3, 2017 6:47 PM > To: Vanessa Maegima; meta-freescale@yoctoproject.org > Cc: desrochers.philippe@gmail.com; festevam@gmail.com; van.ayumi@gmail.com > Subject: Re: [3rdparty][PATCH v2] imx7d-pico: Add machine configuration > (booting) > > > Hello. > I am now trying this with my board and want to make sure if what I am doing > is correct. > >>Add machine definition for imx7d-pico board. >> >>For more information about this reference design, please visit: >> >>https://www.wandboard.org/products/android-things/PICO-PI-IMX7/ > > My local build creates wic.gz file (core-image-minimal-imx7d-pico.wic.gz). > > 1) This is expected to be a one-partition disk image with an ext4 partition > in it? > > (I can see no fat partition for #1, only one ext4 partition. Is this > expected?) > > 2) In serial download mode, I could boot the board using u-boot (using > imx_usb loader tool, by pushing u-boot.imx data to the board). > > 3) However, I am failing to boot it from eMMC. > > I have written u-boot data to 1K offset on the eMMC (/dev/sdc as it is > mounted on the host). > So, at least it should boot into u-boot, but it does not. > > Though looking into hardware manuals for PICP-PI-IMX7, I am seeing > conflicing information on which is the eMMC boot mode setting on the J1/J2 > jumpers, > I tried them but non worked. > > The board as deliverd booted into the default Linux (provided by > technexsion), so the problem is not hardware. > (Unfortunately, I did not take not of the default jumper setting or data of > pre-installed boot loader) > This machine configuration generates the wic image only. This image includes u-boot.imx, dtb, zImage and rootfs and generates only the ext4 partition. The kernel files can be found at /boot. I've created a tutorial on how to build and flash this image, please see it here: https://imxdev.gitlab.io/announcement/The_imx7d-pico_board_is_now_supported_in_FSL_Community_BSP/ The imx7d-pico board is now supported in FSL Community BSP imxdev.gitlab.io The imx7d-pico is a TechNexion board defined here. It is nowsupported in meta-freescale-3rdparty in the master branch. I faced a similar issue as you are facing now. The problem was that the default u-boot by TechNexion was locked and I needed to unlock it in order to flash a new U-Boot. Please see this tutorial: https://imxdev.gitlab.io/tutorial/WaRP7_possible_brick_and_solution/ Please try to unlock your user partition and flash u-boot again in serial downloader mode. You will need to set the right parameters to mmc partconf (mmc partconf dev [boot_ack boot_partition partition_access]) Best, Vanessa