[yocto] ADT: understanding YOCTOADT_TARGET_MACHINE_arch

[Jonathan Austin]

Hi list,

I've been looking at the ADT, and specifically building a custom SDK/ADT 
for a particular board...

This is an ARM board, so I thought I'd set:
YOCTOADT_TARGET_MACHINE_arm="myboard"

Sadly, that doesn't work. I'm trying to understand why.

Despite changing YOCTOADT_REPO in my adt_installer.conf, the 
adt_installer fails to find the cross canadian package group for my board...

Unknown package 'packagegroup-cross-canadian-myboard

Looking at the log, I see that the installer is still looking on the 
yocto servers for (nativesdk) files. I can see that the nativesdk 
locations are hard-coded in opkg/conf/opkg-sdk-i686.conf - so I guess it 
isn't surprising that it can't find the right board, the Yocto servers 
know nothing of myboard at this stage!

Seeing those hardcoded paths made me wonder if I was using the 
YOCTOADT_TARGET_MACHINE_arm variable wrong...

Would it be 'right' to specify just 'arm' here? This is an imx6 board, 
and TARGET_SYS = "arm-poky-linux-gnueabi". By my understanding, this 
will affect which toolchain I get, among other things. I'd defintiely 
like a machine specific sysroot, for example[1]

So - what's the meaning/point of this TARGET_MACHINE_arch option? I see 
that there exists:
packagegroup-cross-canadian-imx53qsb_1.0-r0_all.ipk

  - so clearly someone's felt the need to use something other than just 
'arm' here in the past!

Has anyone else done an ADT for a custom board that uses the ADT 
infrastructure?

Do you create a detailed overlay to the adt-installer recipe and change 
config, etc?

It feels a little like I'm missing a step when generating the ADT that 
tells it more important details about what I'm creating - if so, sorry 
for the questions, but please could you point me there?

Thanks

Jonny

[1] I think that my images currently have to be called 'core-image-xxx' 
to work with existing ADT scripts, unless I'm missing some config 
somewhere, but that's a different issue that I'll dig into shortly