[meta-ti] [PATCH 0/4] IMAGE_FSTYPES fixes / improvements

[Koen Kooi]

Op 9 mrt. 2012, om 20:17 heeft Denys Dmytriyenko het volgende geschreven:

> On Fri, Mar 09, 2012 at 07:43:40PM +0100, Koen Kooi wrote:
>> 
>> Op 9 mrt. 2012, om 16:01 heeft Denys Dmytriyenko het volgende geschreven:
>> 
>>> On Fri, Mar 09, 2012 at 07:20:30AM +0100, Koen Kooi wrote:
>>>> 
>>>> Op 8 mrt. 2012, om 22:01 heeft Denys Dmytriyenko het volgende geschreven:
>>>> 
>>>>> On Thu, Mar 08, 2012 at 12:34:00PM -0700, Tom Rini wrote:
>>>>>> Hey all,
>>>>>> 
>>>>>> This short series does two things.  For 3 machines we fix a bug of using
>>>>>> '?=' rather than '+=' for setting IMAGE_FSTYPES (these are all of the
>>>>>> machines that have this issue today except for...) and on the 4th,
>>>>>> am335x-evm we add UBI support as well.  On the first three, these are
>>>>>> correct by inspection and on the fourth, I've written to and mounted
>>>>>> systemd-image from NAND on my EVM (it didn't work as I was using a custom
>>>>>> uImage that's not systemd-sane, and fixing that and confirming the config
>>>>>> used here works is on my list).
>>>>> 
>>>>> All,
>>>>> 
>>>>> Tom and I started talking on IRC and then decided to move the discussion back 
>>>>> to the mailing list for others to participate.
>>>>> 
>>>>> So, basically, the proposal is to do this in our machine.conf files:
>>>>> 
>>>>> -IMAGE_FSTYPES ?= "jffs2 tar.bz2"
>>>>> +IMAGE_FSTYPES += "jffs2 tar.bz2"
>>>>> 
>>>>> My response was that we shouldn't do that.
>>>> 
>>>> += is the OE classic way of doing things and is IMNSHO the right thing.
>>> 
>>> Not convinced:
>>> 
>>> $ grep IMAGE_FSTYPES openembedded/conf/machine/*|awk '{print $2}'|sort|uniq -c
>>>    30 =
>>>     1 -
>>>    44 ?=
>>>    31 +=
>>> 
>>> BTW, dash in there is a fluke coming from here:
>>> cm-x270.conf:#     - IMAGE_FSTYPES = "jffs2 tar cpio.gz"
>>> 
>>>>> The conf files that may set, append 
>>>>> or overwrite IMAGE_FSTYPES are parsed in the order of local.conf, machine.conf 
>>>>> and distro.conf. And if none of those set IMAGE_FSTYPES, bitbake.conf defaults 
>>>>> to a sane tar.gz. From end-user perspective, they expect the setting in their 
>>>>> local.conf to be obeyed. If they don't care and don't set IMAGE_FSTYPES, then 
>>>>> machine.conf will set it to supported values, i.e. jffs2 and tar.bz2 in our 
>>>>> case. Of course, distro has the last word and potentially can alter it, but in 
>>>>> most cases it shouldn't. That's how it works now and I believe it's the 
>>>>> correct behaviour. Changing it to append additional values to what user wants 
>>>>> is slightly heavy-handed, in my opinion. In other words, those are suggested 
>>>>> image types, not enforced ones.
>>>>> 
>>>>> As Tom poined out, this is the same behaviour as currently used in OE-Core, 
>>>>> where qemu machines all have IMAGE_FSTYPES ?= "tar.bz2 ext3".
>>>>> 
>>>>> The original issue in question may be coming from the way some setup scripts 
>>>>> pre-configure user settings in local.conf, defaulting IMAGE_FSTYPES to 
>>>>> something, that is not very suitable for the machines being used. This needs 
>>>>> to be left unset and for the end-user to decide and set specifically, IMHO.
>>>>> 
>>>>> Comments, opinions?
>>>> 
>>>> See the discussion on OE-core a while back. There was a lot of handwaving 
>>>> done and suggested that IMAGE_FSTYPES_append_$machine = " foo" in local.conf 
>>>> is the right way to do this. I think it's not intuitive because you have to 
>>>> remember that += and _append are expanded in different points during 
>>>> parsing, which requires either deep bitbake knowledge or minor braindamage.
>>> 
>>> Link or it never happened :)
>> 
>> No link, but:
>> 
>> 19:41 < Tartarus> But, where's the oe-core thread?
>> 19:41 < koen> somewhere on OE-core
>> 19:42 < koen> [OE-core] [PATCH 1/2] qemu.inc: append to IMAGE_FSTYPES instead of weakly assigning them
>> 19:42 < koen> july 2011
> 
> Ok, here's the link:
> http://thread.gmane.org/gmane.comp.handhelds.openembedded.core/2060/focus=2061
> 
> It was discussed, there was no resolution, there were no changes.
> 
> Claiming that's how it's done in Classic OE (aka .dev) is not correct - as I 
> showed above, 44 machines use ?=, 31 use += and 31 use =

And how many of those machines are broken/unmaintained/etc

> 
> OE-Core still uses ?=
> 
> Please give me the use case that this is meant to enable, which is not 
> possible now.

Setting a global, additional type in local.conf without needing deep knowledge of bitbake. People just don't understand why they need to do IMAGE_FSTYPES_append = foo instead of IMAGE_FSTYPES += or IMAGE_FSTYPE = "foo"