AGL - Using raw disk images

Purpose

Here are the commands to run on a Linux host to create a bootable SDcard from a full image file and boot a Renesas R-Car Gen3 board (Starter Kit Pro / M3ULCB).

Requirements:

• bmaptools
• SDcard (>2GB) inserted and available at $DEVICE
• the M3 board is preconfigured to boot on SDCard

TLDR; quick instructions for impatients:

• Grab the raw image (*.raw.xz) and the associated bmap file (*.raw.bmap)

• Run:

  $ sudo bmaptool copy *.raw.xz $DEVICE

• Eject SDCard, insert in M3 board and turn it on.

• Enjoy!

Install bmap-tools (recommended)

Bmap-tools is a generic tool for creating the block map (bmap) for a sparse file and copying fioles using the block map. The idea is that large files, like raw system image files, can be copied or flashed a lot faster and more reliably with bmaptool than with traditional tools, like "dd" or "cp".

Bmap-tools sources are available on [github/01org/bmap-tools]. Full documentation is also available (a bit old, but still relevant).

Note: Even if Bmap-tools is not strictly required for operation, it's highly recommended. You can still skip this section if you do not wish to install bmap-tools or don't find any package for it

RPM-based distribution

Bmap-tools is available as a noarch package here: bmap-tools-3.3-1.17.1.noarch.rpm

For example, on Opensuse 42.X:

$ zypper in http://iot.bzh/download/public/tools/bmap-tools/bmap-tools-3.3-1.17.1.noarch.rpm

Debian-based distribution

bmap-tool is available in Debian distribution (not tested).

$ apt-get install bmap-tools

Download AGL image and bmap file

Download the image and the associated bmap file:

• the raw image (*.raw.xz)
• the bmap file (*.raw.bmap)

Write a SDcard

1. Insert a SDcard (minimum 2GB)

2. Find the removable device for your card:

   The following commands which lists all removable disks can help to find the information:

   $ lsblk -dli -o NAME,TYPE,HOTPLUG | grep "disk.*1$"
   sdk  disk       1

   Here, the device we'll use is /dev/sdk.

   Alternatively, a look at the kernel log will help:

   $ dmesg | tail -50
   ...
   [710812.225836] sd 18:0:0:0: Attached scsi generic sg12 type 0
   [710812.441406] sd 18:0:0:0: [sdk] 31268864 512-byte logical blocks: (16.0 GB/14.9 GiB)
   [710812.442016] sd 18:0:0:0: [sdk] Write Protect is off
   [710812.442019] sd 18:0:0:0: [sdk] Mode Sense: 03 00 00 00
   [710812.442642] sd 18:0:0:0: [sdk] No Caching mode page found
   [710812.442644] sd 18:0:0:0: [sdk] Assuming drive cache: write through
   [710812.446794]  sdk: sdk1
   [710812.450905] sd 18:0:0:0: [sdk] Attached SCSI removable disk
   ...

   For the rest of these instructions, we assume that the variable $DEVICE contains the name of the device to write to (/dev/sd* or /dev/mmcblk*). Export the variable:

   $ export DEVICE=/dev/[replace-by-your-device-name]

3. If the card is mounted automatically, unmount it through desktop helper or directly wih the command line:

   $ sudo umount ${DEVICE}*

4. Write onto SDcard

   Using bmap-tools:

   $ sudo bmaptool copy *.raw.xz $DEVICE
   bmaptool: info: discovered bmap file 'XXXXXXXXX.raw.bmap'
   bmaptool: info: block map format version 2.0
   bmaptool: info: 524288 blocks of size 4096 (2.0 GiB), mapped 364283 blocks (1.4 GiB or 69.5%)
   bmaptool: info: copying image 'XXXXXXXX.raw.xz' to block device '/dev/sdk' using bmap file 'XXXXXXXX.raw.bmap'
   bmaptool: info: 100% copied
   bmaptool: info: synchronizing '/dev/sdk'
   bmaptool: info: copying time: 4m 26.9s, copying speed 5.3 MiB/sec

   Using standard dd command (more dangerous):

   $ xz -cd *.raw.xz | sudo dd of=$DEVICE bs=4M; sync

Configure M3 board for boot on SDcard if needed

1. Connect serial console on M3 board and start a terminal emulator on the USB serial port. Here, we use 'screen' on device /dev/ttyUSB0 but you could use any terminal emulator able to open the serial port at 115200 bauds (minicom , ...)

   $ screen /dev/ttyUSB0 115200

2. Power up the board

3. Break at uboot prompt (press any key)

4. Set the following uboot variables:

   WARNING: don't make a big copy/paste or some garbage characters may be sent to the console. Instead, copy one or two lines at a time.

   setenv board m3ulcb
   
   setenv set_bootkfile 'setenv bootkfile Image'
   
   setenv bootkaddr 0x48080000
   
   setenv set_bootdfile 'setenv bootdfile Image-r8a7796-${board}.dtb'
   
   setenv bootdaddr 0x48000000
   
   setenv bootargs_console 'console=ttySC0,115200 ignore_loglevel'
   
   setenv bootargs_video 'vmalloc=384M video=HDMI-A-1:1920x1080-32@60'
   
   setenv bootargs_extra 'rw rootfstype=ext4 rootwait rootdelay=2'
   
   setenv bootargs_root 'root=/dev/mmcblk1p1'
   
   setenv bootmmc '0:1'
   
   setenv bootkload_sd 'ext4load mmc ${bootmmc} ${bootkaddr} boot/${bootkfile}'
   
   setenv bootdload_sd 'ext4load mmc ${bootmmc} ${bootdaddr} boot/${bootdfile}'
   
   setenv bootload_sd 'run set_bootkfile; run bootkload_sd; run set_bootdfile; run bootdload_sd'
   
   setenv bootcmd 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra}; run bootload_sd; booti ${bootkaddr} - ${bootdaddr}'

   Then save environment

   saveenv

Boot the board

At uboot prompt, type:

```
run bootcmd
```

Alternatively, simply start the board.

NOTE: Due to initial operations, first boot can be long (3 to 4 minutes waiting for a timeout on a systemd service). Homescreen may also have problems to start. These issues are known. On next boots, the system should run as expected.