SDK meta-toolchain

SDK meta-toolchain

[Kyle Farnsworth]

I'm a bit confused about what exactly meta-toolchain is building?  It
seems to be bitbaking gcc and creating a toolchain with the prefix
x86_64-oesdk-linux- (default SDK_PREFIX) but I'm not sure what it is.  
Is it a cross-compile for my target MACHINE or a compiler for my build
machine?  Based on the prefix name I am assuming the latter.

Thanks for any help.
Kyle

Re: SDK meta-toolchain

[Mark Hatle]

On 5/7/13 11:09 AM, Kyle Farnsworth wrote:
> I'm a bit confused about what exactly meta-toolchain is building?  It
> seems to be bitbaking gcc and creating a toolchain with the prefix
> x86_64-oesdk-linux- (default SDK_PREFIX) but I'm not sure what it is.
> Is it a cross-compile for my target MACHINE or a compiler for my build
> machine?  Based on the prefix name I am assuming the latter.

There are two ways to generate an SDK.

* targeted SDK -- This is a meta-toolchain* recipe that lists -exactly- what is 
going to be in the SDK.  This is great if you want to limit your SDK to specific 
libraries for your application developers.

* implied / image based SDK -- This type of SDK bases off of what is in the 
image to generate an SDK that contains all of the libraries that are runnable 
inside of the image.  This is a very simple way to generate an SDK for 
application developers that -will- match the run-time image.

Both of the above have their place, depending on the level of command and 
control people want.

The basic meta-toolchain is just the cross compile toolchain and I believe the 
libc.  meta-toolchain-gmae is an example Gnome Mobile Application Environment.

--Mark

> Thanks for any help.
> Kyle
>
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Re: SDK meta-toolchain

[Trevor Woerner]

On Tue, May 7, 2013 at 12:36 PM, Mark Hatle <mark.hatle@windriver.com> wrote:
> There are two ways to generate an SDK.
>
> * targeted SDK -- This is a meta-toolchain* recipe that lists -exactly- what
> is going to be in the SDK.  This is great if you want to limit your SDK to
> specific libraries for your application developers.

Is this the one created using:

    $ bitbake meta-toolchain

?

> * implied / image based SDK -- This type of SDK bases off of what is in the
> image to generate an SDK that contains all of the libraries that are
> runnable inside of the image.  This is a very simple way to generate an SDK
> for application developers that -will- match the run-time image.

Is this the one created by:

    $ bitbake -c populate_sdk <image>

?

Re: SDK meta-toolchain

[Mark Hatle]

On 5/7/13 11:49 AM, Trevor Woerner wrote:
> On Tue, May 7, 2013 at 12:36 PM, Mark Hatle <mark.hatle@windriver.com> wrote:
>> There are two ways to generate an SDK.
>>
>> * targeted SDK -- This is a meta-toolchain* recipe that lists -exactly- what
>> is going to be in the SDK.  This is great if you want to limit your SDK to
>> specific libraries for your application developers.
>
> Is this the one created using:
>
>      $ bitbake meta-toolchain
>
> ?
>
>> * implied / image based SDK -- This type of SDK bases off of what is in the
>> image to generate an SDK that contains all of the libraries that are
>> runnable inside of the image.  This is a very simple way to generate an SDK
>> for application developers that -will- match the run-time image.
>
> Is this the one created by:
>
>      $ bitbake -c populate_sdk <image>
>
> ?
>

Yes to both questions.

--Mark

Re: SDK meta-toolchain

[Kyle Farnsworth]

On 05/07/2013 11:36 AM, Mark Hatle wrote:
> On 5/7/13 11:09 AM, Kyle Farnsworth wrote:
>> I'm a bit confused about what exactly meta-toolchain is building?  It
>> seems to be bitbaking gcc and creating a toolchain with the prefix
>> x86_64-oesdk-linux- (default SDK_PREFIX) but I'm not sure what it is.
>> Is it a cross-compile for my target MACHINE or a compiler for my build
>> machine?  Based on the prefix name I am assuming the latter.
>
> There are two ways to generate an SDK.
>
> * targeted SDK -- This is a meta-toolchain* recipe that lists
> -exactly- what is going to be in the SDK.  This is great if you want
> to limit your SDK to specific libraries for your application developers.
>
> * implied / image based SDK -- This type of SDK bases off of what is
> in the image to generate an SDK that contains all of the libraries
> that are runnable inside of the image.  This is a very simple way to
> generate an SDK for application developers that -will- match the
> run-time image.
>
> Both of the above have their place, depending on the level of command
> and control people want.
>
> The basic meta-toolchain is just the cross compile toolchain and I
> believe the libc.  meta-toolchain-gmae is an example Gnome Mobile
> Application Environment.
Thanks. This a good info.  I need to do the targeted SDK.  But why is it
re-creating the cross-compile toolchain with the new prefix and a libc? 
I also have cases where I want to deliver an external toolchain within
the SDK.

Re: SDK meta-toolchain

[Mark Hatle]

On 5/7/13 12:35 PM, Kyle Farnsworth wrote:
> On 05/07/2013 11:36 AM, Mark Hatle wrote:
>> On 5/7/13 11:09 AM, Kyle Farnsworth wrote:
>>> I'm a bit confused about what exactly meta-toolchain is building?  It
>>> seems to be bitbaking gcc and creating a toolchain with the prefix
>>> x86_64-oesdk-linux- (default SDK_PREFIX) but I'm not sure what it is.
>>> Is it a cross-compile for my target MACHINE or a compiler for my build
>>> machine?  Based on the prefix name I am assuming the latter.
>>
>> There are two ways to generate an SDK.
>>
>> * targeted SDK -- This is a meta-toolchain* recipe that lists
>> -exactly- what is going to be in the SDK.  This is great if you want
>> to limit your SDK to specific libraries for your application developers.
>>
>> * implied / image based SDK -- This type of SDK bases off of what is
>> in the image to generate an SDK that contains all of the libraries
>> that are runnable inside of the image.  This is a very simple way to
>> generate an SDK for application developers that -will- match the
>> run-time image.
>>
>> Both of the above have their place, depending on the level of command
>> and control people want.
>>
>> The basic meta-toolchain is just the cross compile toolchain and I
>> believe the libc.  meta-toolchain-gmae is an example Gnome Mobile
>> Application Environment.
> Thanks. This a good info.  I need to do the targeted SDK.  But why is it
> re-creating the cross-compile toolchain with the new prefix and a libc?
> I also have cases where I want to deliver an external toolchain within
> the SDK.

There are three types of packages in oe-core.

- Target -- runs on the target

- native -- runs on the host (variant called 'cross')

- nativesdk -- runs on the 'sdkhost' (variant called 'crosssdk')

The SDK allows you to build SDK software for a host that is different then your 
build host.  Also the nativesdk is 'glibc' independent, while the native version 
is specific to your host.  This allows the SDK to be shared with other developers.

--Mark

>
>
>
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> http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core
>

Re: SDK meta-toolchain

[Trevor Woerner]

On Tue, May 7, 2013 at 1:41 PM, Mark Hatle <mark.hatle@windriver.com> wrote:
> - nativesdk -- runs on the 'sdkhost' (variant called 'crosssdk')

Is this related to the SDKMACHINE setting?

Re: SDK meta-toolchain

[Mark Hatle]

On 5/7/13 1:21 PM, Trevor Woerner wrote:
> On Tue, May 7, 2013 at 1:41 PM, Mark Hatle <mark.hatle@windriver.com> wrote:
>> - nativesdk -- runs on the 'sdkhost' (variant called 'crosssdk')
>
> Is this related to the SDKMACHINE setting?
>

Yes that's the variable I was thinking of.  You can build an SDK for 'i586' on 
your x86_64 host for instance.

--Mark

Re: SDK meta-toolchain

[Kyle Farnsworth]

On 05/07/2013 01:35 PM, Mark Hatle wrote:
>>> - nativesdk -- runs on the 'sdkhost' (variant called 'crosssdk')
>>
>> Is this related to the SDKMACHINE setting?
>>
>
> Yes that's the variable I was thinking of.  You can build an SDK for
> 'i586' on your x86_64 host for instance.
>

So in my case, since I did not specify SDKMACHINE, it is creating a
toolchain that compiles source into x86_64 executables so it can build
the host tools (i.e automake) on the targeted SDK machine.  And it has
nothing to do with the targeted device cross-compile toolchain?

Re: SDK meta-toolchain

[Mark Hatle]

On 5/7/13 2:33 PM, Kyle Farnsworth wrote:
> On 05/07/2013 01:35 PM, Mark Hatle wrote:
>>>> - nativesdk -- runs on the 'sdkhost' (variant called 'crosssdk')
>>>
>>> Is this related to the SDKMACHINE setting?
>>>
>>
>> Yes that's the variable I was thinking of.  You can build an SDK for
>> 'i586' on your x86_64 host for instance.
>>
>
> So in my case, since I did not specify SDKMACHINE, it is creating a
> toolchain that compiles source into x86_64 executables so it can build
> the host tools (i.e automake) on the targeted SDK machine.  And it has
> nothing to do with the targeted device cross-compile toolchain?

You will get a 'cross' compiler from host -> SDK, and another SDK -> target. 
The SDK -> target is the one that gets installed as part of the SDK.

--Mark

>
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