Date: Sat, 11 Jan 2014 14:00:34 -0700 From: Warner Losh <imp@bsdimp.com> To: John-Mark Gurney <jmg@funkthat.com> Cc: andrew@FreeBSD.org, freebsd-arm@FreeBSD.org, Ian Lepore <ian@FreeBSD.org> Subject: Re: svn commit: r258412 - in head/sys/arm: at91 econa s3c2xx0 sa11x0 xscale/i80321 xscale/i8134x xscale/ixp425 xscale/pxa Message-ID: <D19D8A84-850B-4F14-B1EF-B1A00D0CF2A0@bsdimp.com> In-Reply-To: <20140111205303.GZ46596@funkthat.com> References: <201311210108.rAL18AoQ051365@svn.freebsd.org> <20131221061048.GC99167@funkthat.com> <20140108071643.GB99167@funkthat.com> <1389197091.1158.370.camel@revolution.hippie.lan> <20140108173909.GF99167@funkthat.com> <20140110230241.GS46596@funkthat.com> <20140111135156.251a70fa@bender.Home> <20140111205303.GZ46596@funkthat.com>
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On Jan 11, 2014, at 1:53 PM, John-Mark Gurney wrote:
> Andrew Turner wrote this message on Sat, Jan 11, 2014 at 13:51 +0000:
>> On Fri, 10 Jan 2014 15:02:41 -0800
>> John-Mark Gurney <jmg@funkthat.com> wrote:
>>=20
>>> John-Mark Gurney wrote this message on Wed, Jan 08, 2014 at 09:39
>>> -0800:
>>>> So, I've tested that HEAD (absolutely no tree changes) w/
>>>> WITHOUT_ARM_EABI boots fine... and just to make sure my test is
>>>> correct, I've disabled it too to verify that the kernel just hangs
>>>> (absolutely no output).. and reenabled it and verified it works
>>>> (that my setting is changing something)...
>>>> worky -> no worky -> worky...
>>>>=20
>>>> Now I just realized another interesting thing about setting
>>>> WITHOUT_ARM_EABI, it also fixes the console issue I was having w/
>>>> your call to cpu_setup("") previously (w/ EABI) killing console
>>>> output and not even seeing the mtx panic message...
>>>>=20
>>>> So, it is clearly changing something very early on in boot...
>>>=20
>>> Apparently gcc ARMEB w/ EABI miscompiles code... The code to store
>>> lo_flags in the lock_object is correct:
>>> lock->lo_flags =3D i << LO_CLASSSHIFT;
>>> c03ce2d0: e1a01c06 lsl r1, r6, #24
>>> c03ce2d4: e5881004 str r1, [r8, #4]
>>>=20
>>> But when I add a printf to fetch the data, I get:
>>> printf("lo_classindex: %#x\n", LO_CLASSINDEX(lock));
>>> c03ce2e0: e5d81007 ldrb r1, [r8, #7]
>>> c03ce2e4: e59f0098 ldr r0, [pc, #152] ; c03ce384
>>> <_end+0xffcf9
>>> 19c>
>>> c03ce2e8: e201100f and r1, r1, #15 ; 0xf
>>> c03ce2ec: eb0012ea bl c03d2e9c <printf>
>>>=20
>>>=20
>>> We are doing a ldrb (LoaD Relative Byte) which would be fine to
>>> substitute for the right shift of 24, but only if it loaded the
>>> correct byte.. It should be loading #4 instead of #7 since we are on
>>> big endian...
>>>=20
>>> Anyone who know gcc arm well to figure this out?
>>>=20
>>=20
>> I have an untested fix at [1]. As I don't have any big-endian boards =
I
>> am unable to test the kernel with this.
>>=20
>> Andrew
>>=20
>> [1] http://people.freebsd.org/~andrew/armeb_gcc.diff
>=20
> I have verified that this patch allows me to boot a kernel till it
> mounts root... As I haven't put together a root fs yet, I can't say
> if it goes to single/multiuser yet...
Sounds like a sufficient test to commit it. We can make other fixes if =
there are other issues...
This is assuming that Andrew has tested on LE systems :0
Warner=
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