[U-Boot] am3517: segmentation fault in Linux after upgrading from arago src to mainline u-boot

[Yegor Yefremov]

On Thu, Dec 5, 2013 at 6:28 PM, Måns Rullgård <mans at mansr.com> wrote:
> Yegor Yefremov <yegorslists at googlemail.com> writes:
>
>> On Thu, Nov 28, 2013 at 5:57 PM, Tom Rini <trini at ti.com> wrote:
>>> On Thu, Nov 28, 2013 at 05:39:09PM +0100, Yegor Yefremov wrote:
>>>
>>>> I'm having problems with the new u-boot (November 2013) and am3517
>>>> SoC. When I start Debian 7.0 armhf I get lots of Segmentation faults,
>>>> I can't even perform apt-get udpate. With the older u-boot (arago
>>>> sources from 2010) everything seems to work properly.
>>>>
>>>> I've checked ATAG_MEM and both u-boot versions deliver same RAM start
>>>> address and size. I've compared EMIF4 settings
>>>> (arch/arm/cpu/armv7/omap3/emif4.c) and PINMUX and everything is the
>>>> same.
>>>>
>>>> Where else can I look for differences?
>>>
>>> Can you bisect the arago tree from what it's based on, to what the top
>>> of tree is there?  Some errata or another being patched up I guess..
>>
>> I've compared the x-loader's init routine with the one from SPL. An
>> found this workaround in the mainline U-Boot
>> (arch/arm/cpu/armv7/omap3/board.c):
>>
>> static void omap3_setup_aux_cr(void)
>> {
>>         /* Workaround for Cortex-A8 errata: #454179 #430973
>>          *      Set "IBE" bit
>>          *      Set "Disable Branch Size Mispredicts" bit
>>          * Workaround for erratum #621766
>>          *      Enable L1NEON bit
>>          * ACR |= (IBE | DBSM | L1NEON) => ACR |= 0xE0
>>          */
>>         omap3_update_aux_cr_secure(0xE0, 0);
>> }
>>
>> After commenting this routine and I don't see any segmentation faults
>> during apt usage.
>
> On an r1pX Cortex-A8 (as found in the 35xx chips) you absolutely want
> those bits set, especially if you're running Thumb2 code.  Otherwise you
> will get random crashes.

Where can I find info, if am3517 is r1pX? I've looked through "AM35x
ARM Microprocessor: Technical Reference Manual", but found nothing
similar.

Yegor