FAT partition on newer images

[Alexander Rössler]

Older BBB had a very useful FAT partition when plugged in via USB. The FAT partition was also accessible directly on the SD card. However, I have tested some newer images and saw that some of them still mount the FAT partition but it's not physically present on the SD card anymore. How can I create/modify this FAT partition? It seems to be missing on the latest Machnekit Jessie image.

[Robert Nelson]

Oh, it's been a few years since we nuked that partition..

The "virtual" fat image you see now is just an image *.img file we
started pushing back in 2015.12.04

Last year, i had added a "--enable-fat-partition" option to the sdcard
authoring script:

https://github.com/RobertCNelson/omap-image-builder/commit/f24e65c7b7b63a13c41216f893cde05529101722

There's a "setup_sdcard.sh" example here:

http://elinux.org/BeagleBoardDebian#Debian_.28stretch.29

Just add the --enable-fat-partition option and see what happens...

Regards,

--
Robert Nelson
https://rcn-ee.com/

[Alexander Rössler]

Thanks. The script created a BOOT partition when supplying the --enable-fat-partition command. However, for some reason, it created an ext4 partition called BOOT. When I plug in the BBB  to my computer via USB, it does not show up.

The FAT partition was very useful to supply host drivers and applications with the board.

[Robert Nelson]

On Fri, Sep 1, 2017 at 10:23 AM, Alexander Rössler
<mail.ar...@gmail.com> wrote:
> Thanks. The script created a BOOT partition when supplying the
> --enable-fat-partition command. However, for some reason, it created an ext4
> partition called BOOT. When I plug in the BBB to my computer via USB, it
> does not show up.
>
> The FAT partition was very useful to supply host drivers and applications
> with the board.

Passing the "/dev/mmcblkXp1" node has to be fixed here, when
"has_img_file" is not enabled. (it should only be done when there is 2
partitions)

https://github.com/RobertCNelson/boot-scripts/blob/master/boot/am335x_evm.sh#L514-L534

[Robert Nelson]

correction, it's implemented here:

https://github.com/RobertCNelson/boot-scripts/blob/master/boot/am335x_evm.sh#L466-L481

what does:

journalctl | grep am335x_evm

show in on bootup..

[Alexander Rössler]

Okay, retried with the --img-4gb command.

sudo ./setup_sdcard.sh --dtb beaglebone --enable-fat-partition --enable-cape-universal --enable-uboot-cape-overlays --boot_label SandyBox --enable-systemd --hostname sandybox --img-4gb test.img

Interestingly it still creates a ext4 partition

Journalcmd output

debian@sandybox:~$ journalctl | grep am335x_evm
Sep 01 15:47:24 sandybox sh[641]: generic-board-startup: [startup script=/opt/scripts/boot/am335x_evm.sh]
Sep 01 15:47:24 sandybox sh[641]: am335x_evm: usb_image_file=[/var/local/usb_mass_storage.img]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: uncached cpsw_2_mac: [78:A5:04:CC:90:EF]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_0_mac: [78:A5:04:CC:90:EE]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_1_mac: [78:A5:04:CC:90:F0]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_2_mac: [78:A5:04:CC:90:EF]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_3_mac: [78:A5:04:CC:90:F1]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_4_mac: [78:A5:04:CC:90:F2]
Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_5_mac: [78:A5:04:CC:90:F3]
Sep 01 15:47:26 sandybox sh[641]: am335x_evm: use_libcomposite
Sep 01 15:47:26 sandybox sh[641]: am335x_evm: modprobe libcomposite
Sep 01 15:47:26 sandybox sh[641]: am335x_evm: Creating g_multi
Sep 01 15:47:26 sandybox sh[641]: am335x_evm: g_multi Created
Sep 01 15:47:26 sandybox sh[641]: am335x_evm: Starting usb0 network
Sep 01 15:47:27 sandybox sh[641]: am335x_evm: Starting usb1 network
Sep 01 15:47:28 sandybox sh[641]: am335x_evm: dnsmasq: setting up for usb0/usb1
Sep 01 15:47:31 sandybox sh[641]: am335x_evm: Starting serial...@ttyGS0.service

 debian@sandybox:~$ sudo ls /var/local/

[Robert Nelson]

On Fri, Sep 1, 2017 at 10:57 AM, Alexander Rössler
<mail.ar...@gmail.com> wrote:
> Okay, retried with the --img-4gb command.
>
>> sudo ./setup_sdcard.sh --dtb beaglebone --enable-fat-partition
>> --enable-cape-universal --enable-uboot-cape-overlays --boot_label SandyBox
>> --enable-systemd --hostname sandybox --img-4gb test.img
>
>
> Interestingly it still creates a ext4 partition
>
> Journalcmd output
>
>> debian@sandybox:~$ journalctl | grep am335x_evm
>> Sep 01 15:47:24 sandybox sh[641]: generic-board-startup: [startup
>> script=/opt/scripts/boot/am335x_evm.sh]
>> Sep 01 15:47:24 sandybox sh[641]: am335x_evm:
>> usb_image_file=[/var/local/usb_mass_storage.img]

It's detecting the *.img file, so you'll need to remove that..

sudo rm /var/local/usb_mass_storage.img || true

>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: uncached cpsw_2_mac:
>> [78:A5:04:CC:90:EF]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_0_mac:
>> [78:A5:04:CC:90:EE]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_1_mac:
>> [78:A5:04:CC:90:F0]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_2_mac:
>> [78:A5:04:CC:90:EF]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_3_mac:
>> [78:A5:04:CC:90:F1]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_4_mac:
>> [78:A5:04:CC:90:F2]
>> Sep 01 15:47:25 sandybox sh[641]: am335x_evm: cpsw_5_mac:
>> [78:A5:04:CC:90:F3]
>> Sep 01 15:47:26 sandybox sh[641]: am335x_evm: use_libcomposite
>> Sep 01 15:47:26 sandybox sh[641]: am335x_evm: modprobe libcomposite
>> Sep 01 15:47:26 sandybox sh[641]: am335x_evm: Creating g_multi
>> Sep 01 15:47:26 sandybox sh[641]: am335x_evm: g_multi Created
>> Sep 01 15:47:26 sandybox sh[641]: am335x_evm: Starting usb0 network
>> Sep 01 15:47:27 sandybox sh[641]: am335x_evm: Starting usb1 network
>> Sep 01 15:47:28 sandybox sh[641]: am335x_evm: dnsmasq: setting up for
>> usb0/usb1
>> Sep 01 15:47:31 sandybox sh[641]: am335x_evm: Starting
>> serial...@ttyGS0.service
>

[Alexander Rössler]

I made some modifications to the setup_sdcard.sh and now it creates the flash drive.

The image file does not exist:

debian@sandybox:~$ sudo rm /var/local/usb_mass_storage.img || true  
rm: cannot remove '/var/local/usb_mass_storage.img': No such file or directory

 

Btw. I do not want to boot from the FAT partition. How does the usb_mass_storage.img solution work?

[Alexander Rössler]

Here is how I finally achieved what I wanted:

Code hier eingeben...

sudo apt install doc-beaglebone-getting-started

sudo cp /var/cache/doc-beaglebone-getting-started/beaglebone-getting-started-2017-05-25.img /var/local/bb_usb_mass_storage.img2

sudo apt remove doc-beaglebone-getting-started

sudo rm -rf /var/cache/doc-beaglebone-getting-started/

sudo mv /var/local/bb_usb_mass_storage.img2 /var/local/bb_usb_mass_storage.img

Change usb_ms_ro=0 in /opt/scripts/boot/am335x_evm.sh

Resizing was a little bit tricky but possible using gparted and the loop driver on my host system:

sudo modprobe loop

sudo losetup -f

sudo losetup /dev/loop0 /var/local/bb_usb_mass_storage.img

sudo sh -c "dd if=/dev/zero bs=1M count=500 >> /var/local/bb_usb_mass_storage.img"
sudo gparted /dev/loop0
sudo losetup -d /dev/loop0