Using U-boot in Yocto

Using U-boot in Yocto

[jonas.vautherin]

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Hello!

I am new to Yocto, and hope that this is the right way to ask for help :-).

I would like to have a way to flash my RPi over USB using `fastboot`, and
it seems to me that one way to do that is to enable a "fastboot mode" in
U-boot. Therefore, I am trying to use U-boot in my Yocto image.

There seems to be a recipe for it, hence I just added the package to my `-
image.bb` file:

```
IMAGE_INSTALL += "u-boot"
```

However, I am not really used to bootloaders, and I am not sure it is
booting with it. How can I check if my system is booting with U-boot? It
does not seem like it's appearing in `dmesg` (which I presume is only
starting with the kernel). Do I need to observe that with a serial
connection to my RPi, or is there a log saved somewhere on the system?

Note that my image uses `meta-raspberrypi` for MACHINE "raspberrypi4-64"
(Raspberry Pi 4 Model B).

Cheers,

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Re: [yocto] Using U-boot in Yocto

[Paul Barker]

On Sun, 20 Dec 2020 at 09:02, Jonas Vautherin <jonas.vautherin@gmail.com> wrote:
>
> Hello!
>
> I am new to Yocto, and hope that this is the right way to ask for help :-).
>
> I would like to have a way to flash my RPi over USB using `fastboot`, and it seems to me that one way to do that is to enable a "fastboot mode" in U-boot. Therefore, I am trying to use U-boot in my Yocto image.
>
> There seems to be a recipe for it, hence I just added the package to my `-image.bb` file:
>
> ```
> IMAGE_INSTALL += "u-boot"
> ```
>
> However, I am not really used to bootloaders, and I am not sure it is booting with it. How can I check if my system is booting with U-boot? It does not seem like it's appearing in `dmesg` (which I presume is only starting with the kernel). Do I need to observe that with a serial connection to my RPi, or is there a log saved somewhere on the system?
>
> Note that my image uses `meta-raspberrypi` for MACHINE "raspberrypi4-64" (Raspberry Pi 4 Model B).

The IMAGE_INSTALL variable is used for packages to install into the
rootfs. Typically bootloaders need some special handling and simply
adding them to IMAGE_INSTALL either doesn't work or isn't sufficient
to enable booting via the chosen bootloader.

For Raspberry Pi we made this simple by adding the RPI_USE_U_BOOT
variable which you can set in your distro config or in local.conf. See
https://meta-raspberrypi.readthedocs.io/en/latest/extra-build-config.html#boot-to-u-boot
for more details.

The layer documentation for meta-raspberrypi is actually pretty good,
you can find it at
https://meta-raspberrypi.readthedocs.io/en/latest/index.html.

Thanks,

-- 
Paul Barker
Konsulko Group

Re: [yocto] Using U-boot in Yocto

[Jonas Vautherin]

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Oh, for some reason I had not found the docs. Thanks a lot, that looks
really good!

On Sun, Dec 20, 2020 at 2:13 PM Paul Barker <pbarker@konsulko.com> wrote:

> On Sun, 20 Dec 2020 at 09:02, Jonas Vautherin <jonas.vautherin@gmail.com>
> wrote:
> >
> > Hello!
> >
> > I am new to Yocto, and hope that this is the right way to ask for help
> :-).
> >
> > I would like to have a way to flash my RPi over USB using `fastboot`,
> and it seems to me that one way to do that is to enable a "fastboot mode"
> in U-boot. Therefore, I am trying to use U-boot in my Yocto image.
> >
> > There seems to be a recipe for it, hence I just added the package to my
> `-image.bb` file:
> >
> > ```
> > IMAGE_INSTALL += "u-boot"
> > ```
> >
> > However, I am not really used to bootloaders, and I am not sure it is
> booting with it. How can I check if my system is booting with U-boot? It
> does not seem like it's appearing in `dmesg` (which I presume is only
> starting with the kernel). Do I need to observe that with a serial
> connection to my RPi, or is there a log saved somewhere on the system?
> >
> > Note that my image uses `meta-raspberrypi` for MACHINE "raspberrypi4-64"
> (Raspberry Pi 4 Model B).
>
> The IMAGE_INSTALL variable is used for packages to install into the
> rootfs. Typically bootloaders need some special handling and simply
> adding them to IMAGE_INSTALL either doesn't work or isn't sufficient
> to enable booting via the chosen bootloader.
>
> For Raspberry Pi we made this simple by adding the RPI_USE_U_BOOT
> variable which you can set in your distro config or in local.conf. See
>
> https://meta-raspberrypi.readthedocs.io/en/latest/extra-build-config.html#boot-to-u-boot
> for more details.
>
> The layer documentation for meta-raspberrypi is actually pretty good,
> you can find it at
> https://meta-raspberrypi.readthedocs.io/en/latest/index.html.
>
> Thanks,
>
> --
> Paul Barker
> Konsulko Group
>

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Re: [yocto] Using U-boot in Yocto

[Zoran]

Hello Jonas,

Do not forget that you can also build and use U-Boot completely out of
a YOCTO tree.

I do things like that, not using the YOCTO U-Boot build.

(As a matter of fact, I do not use the kernel as well, only rootfs for
the testing purposes)

But it depends what and how your business/project management model
looks like, I should say.

Zoran
_______

On Sun, Dec 20, 2020 at 3:10 PM Jonas Vautherin
<jonas.vautherin@gmail.com> wrote:
>
> Oh, for some reason I had not found the docs. Thanks a lot, that looks really good!
>
> On Sun, Dec 20, 2020 at 2:13 PM Paul Barker <pbarker@konsulko.com> wrote:
>>
>> On Sun, 20 Dec 2020 at 09:02, Jonas Vautherin <jonas.vautherin@gmail.com> wrote:
>> >
>> > Hello!
>> >
>> > I am new to Yocto, and hope that this is the right way to ask for help :-).
>> >
>> > I would like to have a way to flash my RPi over USB using `fastboot`, and it seems to me that one way to do that is to enable a "fastboot mode" in U-boot. Therefore, I am trying to use U-boot in my Yocto image.
>> >
>> > There seems to be a recipe for it, hence I just added the package to my `-image.bb` file:
>> >
>> > ```
>> > IMAGE_INSTALL += "u-boot"
>> > ```
>> >
>> > However, I am not really used to bootloaders, and I am not sure it is booting with it. How can I check if my system is booting with U-boot? It does not seem like it's appearing in `dmesg` (which I presume is only starting with the kernel). Do I need to observe that with a serial connection to my RPi, or is there a log saved somewhere on the system?
>> >
>> > Note that my image uses `meta-raspberrypi` for MACHINE "raspberrypi4-64" (Raspberry Pi 4 Model B).
>>
>> The IMAGE_INSTALL variable is used for packages to install into the
>> rootfs. Typically bootloaders need some special handling and simply
>> adding them to IMAGE_INSTALL either doesn't work or isn't sufficient
>> to enable booting via the chosen bootloader.
>>
>> For Raspberry Pi we made this simple by adding the RPI_USE_U_BOOT
>> variable which you can set in your distro config or in local.conf. See
>> https://meta-raspberrypi.readthedocs.io/en/latest/extra-build-config.html#boot-to-u-boot
>> for more details.
>>
>> The layer documentation for meta-raspberrypi is actually pretty good,
>> you can find it at
>> https://meta-raspberrypi.readthedocs.io/en/latest/index.html.
>>
>> Thanks,
>>
>> --
>> Paul Barker
>> Konsulko Group
>
>
> 
>