[Buildroot] Why is libbsd limited to ARM, x86 and x86_64?

[Carlos Santos <casantos@datacom.ind.br>]

Two questions, first:

1. Is it enough to build for quemu boards?

2. I'm absolutely ignorant about nios2. What defconfig should I use to build for it? 

Carlos Santos (Casantos)
DATACOM, P&D

----- Original Message -----
> From: "Carlos Santos" <casantos@datacom.ind.br>
> To: "Arnout Vandecappelle" <arnout@mind.be>
> Cc: "buildroot" <buildroot@buildroot.org>, "guilherme machado" <guilherme.machado@datacom.ind.br>
> Sent: Wednesday, February 3, 2016 1:39:51 PM
> Subject: Re: [Buildroot] Why is libbsd limited to ARM, x86 and x86_64?

>> From: "Arnout Vandecappelle" <arnout@mind.be>
>> To: "Carlos Santos" <casantos@datacom.ind.br>, "buildroot"
>> <buildroot@buildroot.org>
>> Sent: Tuesday, February 2, 2016 7:09:28 PM
>> Subject: Re: [Buildroot] Why is libbsd limited to ARM, x86 and x86_64?
> 
>> On 02-02-16 16:30, Carlos Santos wrote:
>>> Hello,
>>> 
>>> I'm working on a project for PowerPC in which libbsd would be useful. However
>>> the package is restricted to ARM, x86 and x86_64 architectures, since Config.in
>>> contains this:
>>> 
>>>   # libbsd requires a.out.h, which is only available for those
>>>   # architectures: arm, x86 (and alpha, currently not supported in Buildroot;
>>>   # also m68k which is currently not enabled, so can't be tested.)
>>>   default y if BR2_arm || BR2_i386 || BR2_x86_64
>>> 
>>> However, my PowerPC toolchain, generated by crosstool-NG, provides the required
>>> a.out.h file. It is based on GCC 4.8.2, GLIBC 2.19 and Kernel 3.10.47.
>>> 
>>> Where does the information about the missing a.out.h on PowerPC comes from?
>> 
>> I had to do some archeology for this one :-)
>> 
>> This exclusion was from the time that we only supported glibc for external
>> toolchains and it didn't get too much attention. So we missed the fact that
>> glibc doesn't include linux/a.out.h so you won't get this[1] error. And it also
>> seems that libbsd doesn't really require a.out support in the architecture (PPC
>> doesn't support a.out), it just needs the a.out.h file to be present (in uClibc,
>> a.out.h includes linux/a.out.h; in glibc, it doesn't). So for glibc, it works on
>> any architecture.
>> 
>> Sometime later, the bump to 0.6.0 made libbsd require a glibc toolchain [2].
>> But of course, nobody noticed that this meant that the architecture dependencies
>> are no longer needed.
>> 
>> So it would be great if you could prepare a patch that removes the arch
>> dependency and test if libbsd builds on all the arches that have glibc: aarch64,
>> mips, sh, microblaze, sparc, nios2.
>> 
>> Regards,
>> Arnout
>> [1]
>> http://autobuild.buildroot.org/results/019/019091312ec547520370ffad967b53e23f54a14b/
>> [2]
>> http://autobuild.buildroot.net/results/e94/e949d8fabeeecc74bd1c324c516e0b4938c99dbc/
> 
> OK, I will submit a patch.
> 
> Carlos Santos (Casantos)
> DATACOM, P&D